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IOWA

GEOLOGICAL SURVEY

Bulletin No. 4

THE WEED FLORA

OF IOWA
Eby L eee ales

GEORGE F. KAY, STaTE GEOLOGIST
JAMES H. LEES, ASSISTANT STATE GEOLOGIST

DES MOINES:
PUBLISHED FOR IOWA GEOLOGICAL SURVEY
1913

DES MOINES
ROBERT HENDERSON, STATE PRINTER
JOHN M. JAMIESON, STATE BINDER

1. OF D.
WAY 7 1914

GEOLOGICAL BOARD.

Eismihxcellency, George W. Clarke: .)o2.. -.. 0.2.2. 0.055 Governor of Iowa
EEKCHAMmme OLATIbere Mls] CAV CLV As atiaha io sire rat opoustonitcle anets: sysbadeceon je speielaraieitele Auditor of State
PCN eMES OWI ELMe ss ley arrete ste ciee) vie susie President State University of Iowa
ey monly Aes SATS OM rer c.0 seo) «scsi, si eueseieleve miso President Iowa State College
(CPPCC Vic cis cc cies exe a ere eia. eee President Iowa Academy of Science

ADMINISTRATIVE OFFICERS.

GeOGe mE) RAY oso. oasis s Ce, RARE IAT, MMM OU POT at Rte a State Geologist
20083 IST Ieee oping dsich oon veo umes poeta Assistant State Geologist
EIDE RUMEN EG wimaiiee ec AN ee es hoy uns oa SOCRetAry

LETTER OF TRANSMITTAL

Iowa Geological Survey.

To Governor George W. Clarke and Members of the Geological
Board:

GENTLEMEN: I submit, herewith, a bulletin on The Weed Flora
of Iowa and recommend that it be published for distribution among
the people of the state.

‘The thanks of the whole state are due Dr. L. H. Pammel of the
Iowa State College of Agriculture and Mechanic Arts for the
preparation of a comprehensive and thorough report, represent-
ing many years of careful and painstaking scientific work, on a
subject that is most intimately related to agriculture, the industry
that far exceeds in importance all other industries of our great
state.

The Survey wishes to express its thanks to Dean Curtis, Director
of the Iowa Agricultural Experiment Station, for his co-operation,
and for his kindness in permitting the Survey to include in the
bulletin on weeds results of investigations which were carried for-
ward by Doctor Pammel while connected with the Experiment
Station.

The Iowa Geological Survey had the honor, about ten years
ago, to publish a complete monograph by Doctor Pammel on the
Grasses of Iowa. This publication proved to be of great value,
and it is with the fullest confidence that the bulletin on The Weed
Flora of Iowa will be of equal if not of greater service to the
agricultural and related interests of the state that it is now pre-
sented for publication as Bulletin 4 of the lowa Geological Survey.

I have the honor to be,

Yours very sincerely,
Grorce F. Kay,
State Geologist.

THE WEED FLORA OF IOWA

By L. H. PAMMEL

WITH THE COLLABORATION OF.

CHARLOTTE M. KING J. N. MARTIN J. Cc. CUNNINGHAM
ADA HAYDEN and HARRIETTE S. KELLOGG

TABLE OF CONTENTS

CHAPTER I.
Page
MS Cregeen LAIN alleneyeyeic et ecu wenenneietes cre Row ccna lreallel alone, seer ervunoe le clahelbie era wee 1
CHAPTER II.
The General Characters of Seeds. BORSA ch i a eI Fey aN A/a Ml Dele ie 405
CHAPTER III.
The Microscopic Structure of Some Weed Seeds....................-.. 503
CHAPTER IV.
Morphology of Flowers and Leaves.......... Per aan ey a Asta cepa n aerate oak ne NUN oe 589
CHAPTER V.
Cale rg mG lem OUS starccet ste ous tetera orca Gia reevencl seatm a: St Setar atireene slave: maecsie balers 627
CHAPTER VI.
ECOULSH AMC OOt-StOCKS! Ob NVECUSm anne daistccde aelsule oss a ee cae one ome 641
CHAPTER VII.
Number and Kinds of Weeds in Different Soils........................ 655
CHAPTER VIII.
MMA UNO MISTS SHOeNVCCUS Hare pace cake se alors lara ecdtava seus oe aereractte, oe MNecciteensiale Ceeeiece 669
CHAPTER IX.
NCCC am VIN eae OMmec erento auc aun ska Rhos Bas er eels Wendie) am ht e 685
CHAPTER X.
ISA SG LAST WHY SRG) ai ssn ste see aCe Petco eae RS Te RS a A TTA
CHAPTER XI.
ENEMMIOO Sy Ole WICC US a eters seers seis ie o's p.oleisiors wate alee bea do weahe edhe ivan 783
CHAPTER XII.
Weed! Bing! Seeel SIRNAS Se Ramee rec oe oleae et Re ier ry rer oc 791
CHAPTER XIII.
ISUISIONPA BANG! TEMTOIbIOVSR FEN olalira yoke Hike Amiens arte Ele Gee ane a 817

GIOSSEIAT ~ iodo 5 5) 5 S!SfD ie as Ho Goa Eee EEO Eee ed es 862

PREFACE

Weeds do an enormous damage to the crops of lowa. A con-
servative estimate places the injury at $25,000,000 annually. This
loss could be largely avoided if we had more concise information -
on the subject, and if we could conserve: the matchless resources
of our soil by keeping the weeds down, the farmers would be greatly
benefited in a financial way. It would seem appropriate, therefore,
to publish a volume of the Weed Flora of the state at this time.

_ The need of a volume dealing with Iowa weeds as a feature of
the flora of the state has long been felt by the public schools.
Many papers have been published by the Iowa Agricultural Ex-
periment Station, but these papers are mostly out of print. This
work is much more comprehensive than anything heretofore pub-
lished in this state. The title indicates that it is not a weed book,
but rather ia weed flora. Much stress has been laid on the geograph-
ical distribution of weeds. It is a contribution to the local flora
of the United States.

The chapter on the geographical distribution of weeds will be
found of special interest to the phytogeographer. I desire to ex-
press my thanks to Dr. M. L. Fernald, Messrs. R. I. Cratty, F. W.
Paige, O. M. Olson, J. P. Anderson and Prof. B. Shimek for assist-
ance in giving the geographical distribution of Iowa weeds. The
chapter on the microscopic structure of weed seeds brings together
in English much on the subject which has hitherto been inacces-
sible to the student not familiar with German or French ltera-
ture. The chapter on morphology will greatly help the student to_
understand the changes occurring in the development of the flower
and the formation of the seed. The chapter on the use of weeds
in medicine will be of interest to those who occasionally make use
of wild plants for medicinal porposes. The chapter on seeds de-
scribes a large number of weed seeds; this will be found of value
to those engaged in a study of seeds.

The chapter on various weed laws gives a summary of laws
in various states in the Mississippi Valley. In compiling these

xii PREFACE

laws I have been aided by Mr. Small of the Iowa State Library,
Mr. Moore of Wisconsin, Mr. Michel of South Dakota, Dr. Howard
of Missouri and H. L. Bolley of North Dakota.

In the preparation of this Weed Flora, I have been greatly
assisted by Professor J. N. Martin, who has written the chapter
on morphology of the plant; Miss Ada Hayden, who has written
the chapter on dissemination; Professor J. C. Cunningham, who
has written the chapter on roots and underground organs; Miss
Charlotte M. King, who is the joint author of the chapters on gross
characters and microscopic structure of seeds. Miss King is also
responsible for many of the excellent drawings. The chapter on
medicinal weeds was prepared by Miss Kellogg. I am greatly in-
debted to her for painstaking editorial work and for preparing the
bibliography and the index. In the matter of bibliography, it has
seemed best to divide the subject into various sections so that the
student may easily find the desired literature. The bibliography
is not complete but enough papers are given to enable the student
to find the important literature. JI am indebted to Dr. Clark, of
the Canadian Seed Laboratory, for the privilege of using some
of the admirable illustrations of the Canadian work on weeds,
also to Dr. Ernest Bessey for illustrations from Beal’s Weeds
of Michigan, and the classical Hillman seed figures in the Michi-
gan bulletin, and to the Nevada Station for the use of the Hill-
man cuts. Some of the Hillman and a few other figures have
been taken from the government publications. I am also indebted
to various publishers for figures which have been taken from sev-
eral textbooks of botany, as the Bergen & Davis book published by
Ginn & Co.; several botanical works like Thomé’s published in
German, and to the Connecticut Experiment Station. A few fig-
ures have been taken from the Botanical Gazette. Credit is given
under each figure. The photographs were made by F. E. Colburn,
photographer at the Iowa Agricultural Experiment Station, G. T.
Hart and C. R. Quade. The clerical work of the volume was per-
formed by Miss Bertha Herr and my daughter, Miss Harriet.
Mr. Burlingmair assisted in a study of weeds in different fields.
To Mr. James H. Lees for his assistance in proof reading and edi-
torial work I am also indebted. To all I wish to express my sincere
thanks.

The reader will find it advisable to have several of the recent
treatises on weeds. Mention may be made of my work ‘‘ Weeds of
the Farm and Garden,’’ a general treatise of three hundred pages

PREFACE xiii

with numerous illustrations; the work of Fletcher and Clark of
Canada; Bolley’s *‘North Dakota Weeds;’’ Blatchley’s ‘‘Indiana
Weed Book;’’ W. J. Beal’s ‘‘The Weeds of Michigan.’’ A list of
these publications and where they may be obtained will be found
in the bibliography.

Ames, Iowa, December 18, 1912. .
: L. H. PAMMEL.

Page 754

Page 837

Page 838

Page 842

Page 858

Page 861

Rosenberg, 1882 should be 1782.

Patrick, P. E., should be Patrick, G. E.
Blankenship should be Blankinship.
L. T. Henderson anol be L. F. Henderson.

Panton, J. H. Weeds of Ontario should be listed on
page 845.

T. L. Williams should be T. A. Williams.

CHAPTER I.
DESCRIPTIVE MANUAL

L. H. PAMMEL

CHAPTER I.

KEY FOR FAMILIES.

I. Plants without true flowers; not producing seeds...Pteridophyta.
Stemsmyoimted, TUShliKe. jac ccs cero ders ec ne le ss ec Hquisetaceae.

I. Plants with true flowers, stamens, and pistils and producing seeds.

Spermatophyta.

II. Ovules not borne in a closed ovary (Pine, Spruce)..........

Gymnospermae.

II. Ovules borne in a closed ovary (Rose, Willow, Corn, etc.)....

III.

ITI.

Angiospermae.

Stems endogenous without central pith; no annual rings;
parts of the flower usually in threes; single cotyledon...
: Monocotyledoneae.
1. Grasslike plants 2.
2. Flowers enclosed by chaff-like scales.
Stems hollow; sheaths of leaves split...Gramineae.
Stems solid; sheaths of leaves not split. Cyperaceae. ©
2. Flowers not inclosed by chaff-like scales. .Juncaceae.
1. Plants not grasslike; flowers with a perianth of 6
DICCESGMSCAIMENISS Gah eienevatel svar cnoveusrate eben cis atcher cere Liliaceae.

Stem formed of bark, wood, and pith, exogenous; ieaves
netted-veined; embryo with a pair of cotyledons.........
Dicotyledoneae.
1. Corolla absent
7, IPMGNOES WSN; Op SCUNPA TS Gia bonoodbodE Chenopodiaceae.
2. Plants not fleshy or scurfy 3.
3. Ovary free 4.
4, Flowers unisexual.

Ovaryral=celle@ dl We erciesletere ate we eranestcleisns Urticaceae.
Oviatyars-¢ clledeea anes eiciseo Huphorbiaceae.
4. Flowers perfect.

Calyx and bracts greenish and scarious......
Amaranthaceae.

Calyx generally corolla-like.
1. Fruit a i1-seeded achene..... Polygonaceae.
1. Fruit a 5-12 seeded berry. ..Phytolaccaceae.
Se OVA MERTON te alsa eleve eles siedele re: wicvers Nyctaginaceae.

1. Calyx and corolla present.
2. Corolla of separate petals 3.
3. Plants fleshy, flowers yellow........ Portulacaceae.

WEED FLORA OF IOWA

3. Plants not fleshy 4.
4. Pistil single 5.
5. Flowers regular.
Stamens numerous, free...Ranunculaceae.
Stamens numerous; sepals and petals pres-
ent, inserted on calyx........... Rosaceae.
Stamens 10; fruit a legume...Leguminosae.
4. Pistil compound 6.
6. Ovary free.
Ovary l-celled ........... Caryophyllaceae.
Ovary more than 1-celled 7.
7. Ovaries united into a ring...Malvaceae.
7. Ovaries not united into a ring 8.
8. Leaves simple.
With punctate dots; stamens numer-

OUSHARie aseeneener A rors ., Hypericaceae.
Leaves not with punctate dots; sta-
NNT Hosgaqasosnabdousads Cruciferae.
Leaves compound, pinnately 3-foliate.

Anacardiaceae.
Leaflets 3, obcordate..... Oxalidaceae.

Leaflets 5-7 pairs..... Zygophyllaceae.
Leaflets 3, viscid or fetid herbs.....

Capparidaceae.
6. Ovary adherent; flowers in umbels.....
Umbelliferae.
6. Flowers not in umbels....... Onagraceae.

1. Calyx and corolla present, petals more or less united.
2. Flowers regular 3.
38. Plants with milky juice.

Stamens united .............-.0e8- Asclepiadaceae.

Stamens distinct ................... Apocynaceae.
3. Plants without milky juice.

4 Plants Gwinn eee ce eesierete eters Convolvulaceae.

4, Plants not twining 5.
5. Stamens 5 or more 6.
6. Style 2-cleft; flowers not in heads; fruit
2-4 seedlike nutlets.......... Boraginaceae.
Fruit many seeded pod...Hydrophyllaceae.
Flowers in heads; anthers in ring or

tube about the style......... Compositae.

6. Style 1; fruit many seeded..... Solanaceae.
5. Stamens fewer than corolla lobes

Caulescent, flowers blue ........ Verbenaceae

Acaulescent, flowers greenish. Plantaginaceae

2 Flowers irregular.
Stems 4-angled; ovary deeply 4-lobed...... Labiatae.
Stems not 4-angled; ovary 2-celled. .Scrophulariaceae.

DESCRIPTIVE MANUAL 4)

PTERIDOPHYTA, FERNS AND THEIR ALLIES.

This group of plants, sometimes called vascular cryptogams, Is
represented in our flora by the maidenhair fern, brake, spleenwort,
shield fern, ete. The Boston fern is frequently cultivated.

Fic. 1. Common Horsetail (Hquisetum arvense). Roadsides, fields, common
everywhere in Iowa.

(Photographed by Colburn.)

Fic. 1-A. Distribution of Common Horsetail.

6 WEED FLORA OF IOWA

EQUISETACEAE, HORSETAIL FAMILY.

This small family of rushlike plants contains a few species only
and but one that is weedy.

Common Horsetail (Equisetum arvense L.).

Description—A rushlike perennial with running rootstocks and
annual stems; branches in whorls; fertile and sterile plants, the
fertile appearing early in spring with a terminal cone, yellowish
in color, bearing the spore cases (sporangia) underneath a scale;
spores provided with hygroscopic bands; sterile frond with
whorled branches.

Distribution — Widely distributed in North America, common in
sandy moist fields, on railroad embankments; common in Story,
Boone, Carroll, Crawford, Harrison, Woodbury, Clinton, Dubuque,
Lee, Page, Polk, Cerro Gordo, Emmet, Webster, Marshall, Johnson,
Winneshiek and Allamakee counties

Extermination.—This is a most persistent perennial; only by giv- |
ing frequent shallow cultivation after small grain is removed
during the summer can the weed be kept in check.

SPERMATOPHYTA, FLOWERING PLANTS.

The seed plants have stamens and pistils and reproduce by seeds.
Represented by the pine, spruce, hemlock, wheat, rye, corn, rose,
maple, ash, aster, goldenrod, squash, ete.

GYMNOSPERMAE, GYMNOSPERMS.

The seeds are not inclosed in an ovary. Trees or shrubs gener-
ally with needlelike or scalelike leaves; represented in Lowa by
the red cedar, white pine, etc. Noné are weedy.

ANGIOSPERMAEH, ANGIOCSPERMS.

Ovules borne in a closed ovary. Represented by a large number
of our native and cultivated plants, like wheat, corn, lily, rose,
clover, tomato, ete.

MONOCOTYLEDONEAE, MONOCOTS.

Plants with endogenous stem, the woody fibers in bundles dis-
tributed through the pith. Annual ring absent. Flowers gen-
erally on the plan of 3; embryo with a single cotyledon. Corn,
lily, onion, asparagus, blue grass, switch grass are representatives.

DESCRIPTIVE MANUAL ts

GRAMINEAE, GRASS FAMILY.

This large family is of great economic importance, since it con-
tains many of our food plants, including the well known cereals,

\
tn

Fic. 2. Johnson Grass (Sorghum halepense) ; a, sessile spikelets. A most trou-
blesoume weed.
(Lamson-Scribner, U. S. Dept. Agr.)

Fic. 2-A. Distribution of Johnson Grass. Reported recently from southwestern
owa.

8 WEED FLORA OF IOWA

rye, wheat, oats, barley, corn, kaffir corn and millet, besides such
forage grasses as blue grass, timothy, brome grass, foxtail, and a
few ornamental plants, ike pampas grass, ribbon grass, ete.

Johnson Grass (Sorghum halepense (.) Pers.).

Description.—A_ stout perennial, with smooth, erect, simple
culms, 3-5 feet high, and strong, creeping rovt-stocks; leaves
elongated, 14-34in. wide, acute; ligule ciliate, and on the back
where leaf-blade joins the sheath there is more or less pubescence ;
panicle open, 6-12 in. long, the whorled branches naked below, the
3-5-flowered racemes clustered towards their extremities; pedicels
of the staminate (rarely neutral) spikelets pilose with stout hairs;
sessile spikelet broadly lanceolate, acute, 2-3 lines long, pale green
or violet, becoming dark or nearly black at maturity; callus small,
obtuse, shortly and sparsely barbate; first glume coriaceous, spar-
ingly pubescent on the flattened back, 5-7-nerved; second glume
similar and equaling the first, convex below, subcarinate above,
acute, the hyaline inflexed margins ciliate; third glume a little
shorter than the outer ones, membranous, faintly 2-nerved, the in-
folded margins ciliate; fourth glume broadly oval, obtuse, nearly
1% shorter than the second, 2-lobed or bidentate at the apex, ciliate
awned; awn 5-8 lines long; palea a little shorter than the glumes,
nerveless, ciliate. Introduced and cultivated in many southern
states for hay; in many places it has become a dangerous weed,
difficult to exterminate.

Distribution.—The weed is common in the south, often a most
troublesome weed. It has been reported as persisting in the
vicinity of Hamburg, Fremont county.

Extermination.—Use the same methods as for quack grass. This
may become a most troublesome weed.

Finger Grass (Digitaria sangwinalis (L.) Secop.).

Description—A much branched, leafy annual, 1-3 ft. high,
spreading on the ground, with erect, smooth, spreading culms, fre-
quently rooting at the lower joints, joints sometimes smooth, though
more frequently bearded with deflexed hairs; sheaths loose, gener-
ally pilose, hairy, ciliate on the margins, with a membranaceous
ligule; leaves 2-4 in. long with rough margins, occasionally pilose
at the base; flowers produced in digitate spikes, hence the common
name finger grass; spikelets less than 14 in. long in pairs, 1 nearly
sessile, the other with a stalk, each flower consisting of 2 sterile

DESCRIPTIVE MANUAL

Fic. 3. Common Crab Grass (Digitaria sanguinalis). Common in fields, gar-
dens, meadows. Rooting at the joints.

(Photographed by Colburn.)

— Si
a ator Mitchel ties
ROMA SauPene * fe le
Kossuth = ote a
Ay . Bai AO z
*. ‘|: CL |RAko
+ ° . is .
mf . 2 : 2. 2
Sure .
a Tel . + dubug
Z ce . re
° 47 Sle ot
a is ee
:
5 rene eo bt t,]. Ce ole =
+. es Geet ate =
Se a hee eet = 2 Clinton
C a - tr . eo bohvsbw eis
e : es| Ma Ra eed lie +
- = = Hieiscarine
ONG fs z Keokuk =
awaited mie + 5
ote ° a5 +>
. =o
’ # Henn
/ | E ae +
a A faye Decatur a
c + | +. Fe +
the he ee Se ee ee %

Fic. 3-A. Distribution of Common Crab Grass.

glumes and the flower proper; the first glume very small, the sec-
ong about 14-24 as long as the spikelet, usually hairy on the mar:
gin, the third glume somewhat longer than the fourth, which is 5-

10 WEED FLORA OF IOWA

nerved and usually silky-villous along the marginal nerves, fourth
glume smooth and acute; fruit minute, pitted and cross-striated,
light straw color except where the sterile glumes remain attached,
which are gray in color and minutely hairy.

Distribution.—This European grass is cosmopolitan; abundant in
the eastern and southern states and in California; common in all
parts of Iowa, more particularly in gardens, corn fields, and streets.

Extermination—tThis grass is much more difficult to remove than
the foxtails because it roots so readily at the joints. Thorough
cultivation will remove the weed. Do not allow it to go to seed.

Chemical Composition—Common crab grass (Digitaria sanguin-
alis) has been used as a forage plant in many parts of the United
States and many chemical analyses have been made. Analyses are
reported from Mississippi, Tennessee and lowa. The Iowa analysis
reported by Weems is as follows:

NATURAL CONDITION

Albu~ Crude Nitrogen
Sample Water Fat Protein minoids Fiber Ash free
extract
‘he a ee 66.95 Ul 2e02 (1.98) 8.62 4.10 16.70

WATER FREE SUBSTANCE

see ase 2 | eee eee | 3.34 | 7.61 | (5.98) | 26.11 | 12.41 | 50.53

Smooth Crab Grass (Digitaria humifusa Pers.).

Description.—An annual 6 in.-2 ft. high, closely resembling D.
sanguinalis in habit, but smooth throughout, excepting for a few
hairs at the throat of the sheaths; spikelets 2-7, smaller than in
D. sanguinalis, about 1 line in length; first glume very minute or
obsolete; second and third glumes nearly equal in length, or the
second a little shorter than the fourth, pubescent at the back.

Distribution—Smooth erab grass is native to Europe but is
now cosmopolitan; in eastern North America from New England
to Texas and Mexico, Rocky mountains and Pacific coast; less com-
mon in Iowa than common crab grass; rapidly spreading in the
state, more particularly in gardens; common in lawns and pas-
tures.

SES:

[Z
= ex
aS Sc
===
SS
a
xe

Fic. 4.
Fic. 4-A.

Tt DEE
SO _

S$

S

Figure 4
Crab Grass (Digitaria sanguinalis).

Figure 4A

——
SEOQEE

<a
2

NS RS <:

Ce

i
x3
ee ater ae

<23
—
SS

ee
Sy “Ra

SQ

Common in cultivated fields.
fusa); a, leaf with sheath; b

Smooth Crab Grass (Digitaria humi
spikelet; c, d, scales, stamens and pistils. Common in gardens and lawns.

(Drawn by C. M. King. )

4

12 WEED FLORA OF IOWA

“ug a h E iN : Be
PO eee
erie a

eae han ee?

Fic. 4-B. Distribution of Smooth Crab Grass.

Extermination—This weed is somewhat more difficult to exter-
minate than the foxtail, especially in lawns where it is common.
Here it produces seed so close to the ground that the lawn mower
will not catch this part of the plant. It may, however, be easily
destroyed in fields which are cultivated. Stir the soil with a cul-
tivator or hoe, exposing the roots to the sun.

Old Witch Grass (Panicum capillare L.).

Description.—An annual with usually coarse, branching stems,
1-3 feet long, with very hairy leaf-sheaths and capillary, widely
spreading panicles, terminal on the culm or its branches; culm
geniculate and branching near the base, rarely simple, generally
pilose or pubescent below the bearded nodes; sheaths pilose to
densely hirsute, with spreading hairs; ligule very short, densely
ciliate; leaf-blade flat, lanceolate or linear, acute, usually thinly
hairy on both sides, margins scabrous and ciliate near the base;
hairs throughout spring from small papilla, those on the leaf-blade
being confined chiefly to the principal nerves; panicle diffuse, 3-12
in. long, the branches solitary in pairs, or rarely whorled, the ulti-
mate branches and pedicels strongly hispid; spikelets 1 line long,
ovate, acute, or abruptly acuminate-pointed, smooth; first glume
clasping the base of the spikelet, obtuse or acute, 1-3-nerved, about
1% the length of the 5-7-nerved and nearly equal second and third
glumes, the acute tips of which are sometimes minutely pubescent ;
flowering glume smooth and shining, elliptical, obtuse, or subacute,
a little shorter than the larger outer glumes. Variable. July to
October.

DESCRIPTIVE MANUAL 13

Fic. 5. Tickle Grass (Panicum capillare). Common in fields and gardens, etc.
(Photographed by Hart.)

Fig. 5-A. Distribution of Tickle Grass.

14 WEED FLORA OF- IOWA

Distribution Old witch grass is common throughout the state,
frequently as a weed. It is variable, the form occurring in cul-
tivated fields being stout and hispid; but when occurring in moist
meadows and old lake beds it has slender and somewhat capillary
branches. In Iowa it is quite common in Plymouth, Woodbury,
Muscatine, Story, Emmet, Franklin, Clinton, Carroll, Crawford,
Pottawattamie, Scott and other counties.

Extermination.—This annual grass is easily exterminated by cul-
tivation. It seldom gives trouble in well cultivated corn fields. It
might be well also, when the weed is abundant, to rotate with some
leguminous crop.

‘Sprouting Crab Grass (Panicum dichotomiflorwm Mx.).

Description—A smooth, usually much-branched annual with
stems 2-4 or 6 ft. tall, rather coarsely spreading or ascending
(rarely erect); long, flat leaves and diffuse terminal and lateral
panicles; sheaths smooth, lax, somewhat flattened; ligule ciliate;
leaf-blade 6-12 or 24 in. long, 2-10 lines wide, acute, scabrous on
the margins and sometimes also on the prominent nerves, rarely
pilose on the upper surface; panicles pyramidal, 4 or 5-12 or 15
in. long, the primary and secondary branches spreading, scabrous;
spikelets rather crowded upon short, appressed and scabrous pedi-
cels, lanceolate-ovate; acute 1-114 lines long, smooth, green or
purplish ; lowest glume embracing the base of the spikelet, usually
obtuse and nerveless, rarely 1-3-nerved, 1/4,-14 as long as the
nearly acute 5-7-nerved second and third glumes, the latter having
sometimes a hyaline palea in its axil; floral glume elliptical, sub-
acute, smooth and shining, a little shorter than the larger outer
glumes; anthers saffron yellow.

Distribution.—Widely distributed in eastern North America,
common in many parts of Iowa, as Ames, Des Moines, Sioux City,
Council Bluffs, Davenport, Eddyville.

Extermination—Prevent the formation of seed and give thor-
ough cultivation.

DESCRIPTIVE MANUAL 15

a

Fic. 6. Sprouting Crab Grass (Panicum dichotomiflorum) ; a, b, ¢, spikelets;
d, e, flowering glume. Widely distributed in the state.

\ \\
IN
© NY, \) iy

ae

fl

Fie. 6-A. Distribution of Sprouting Crab Grass.

16 WEED FLORA OF IOWA

Barnyard Grass (Echinochloa crusgalli (.) Beauv.).

Description.—A coarse, ascending, leafy annual 1-5 ft. high,
with wide leaves; spike 1-3 in. long, crowded in a dense panicle;

Fic. 7. Barnyard Grass (Hchinochloa crusgalli). Fields, barnyards and road-
sides.
(Photographed by Hart.)

Fic. 7-A. Distribution of Barnyard Grass.

DESCRIPTIVE MANUAL 17

culms frequently branched near the base; sheaths loose; smooth or
sometimes hispid; leaves broad and flat, 6 in.-1 ft. or more long;
smooth or roughened, margin roughened; spikelets densely and ir-
regularly crowded in several rows along one side of the spikelike
branches of the panicle, 114 lines long, outer glume or bract from
14-14 the length of the spikelets, second and third glumes smooth,
pubescent or hispid along the nerves, fourth glume smooth, awn-
less or short awn-pointed.

Distribution Barnyard grass is native to Iowa, also to other
parts of North America, and is quite generally distributed, par-
ticularly in barnyards, on shores of lakes, streams and in gardens,
‘but is most abundant in low places.

Extermination—By thorough cultivation and preventing the
formation of seeds.

Chemical Composition—Chemical analyses of this grass have
been reported from Iowa, North Carolina, South Dakota and
Mexico. Weems reports the following composition from Iowa ma-
terial.

NATURAL CONDITION

|
Albu- Crude Nitrogen

Sample Date | Height Water Fat Protein | minoids | Fiber Ash free
i extract
1

ee |e eee eee er 76.34 «73 1.43 (1.35) 9.44 2.47 9.59

WATER FREE SUBSTANCE

se a | a eS COALS | 3.09 | 6.07 | (6.73) | 39.00 10.46 | 40.48

Pigeon Grass, Foxtail (Setaria glauca (li.) Beauv.).

Description—An erect annual 1-214 ft. high; with flat leaves;
bristly cylindrical spike, from 1-3 in. long; heads slender; bristles
tawny yellow; small seeds conspicuously cross-striated and easily
distinguished from the next species because of their larger size
and by the cross-striation.

Distribution—This weed is quite generally distributed in the
United States, particularly in eastern states. It occurs every-
where in the state of Iowa, particularly in corn fields, where it
comes up abundantly, after the corn is ‘‘laid by:’’ also in gardens

and in pastures, especially in the fall.
2

18 WEED FLORA OF IOWA

Extermination.—It is not generally recognized, but it is prob-
ably true, that more money is spent in the extermination of fox-
tails than of any other class of weeds we have in the state of lowa,
yet they are all easily destroyed. One of the best and most effective
methods of destroying the foxtail is by plowing the small grain
field as soon as the grain is removed. If this is not done a large
amount of seed is produced. After this plowing in the fall the
field should be disked and harrowed in the spring and then planted
to corn. The corn should be cultivated as frequently as possible,
at least four or five times. This method should prove effective for
the destruction of foxtail and pigeon grass.

Vic. 8. Pigeon Grass (Setaria glauca) ; a, spikelet showing the second glume,
the upper portion of the flowering glume and bristles; b, spikelet showing
the back of the first and third glumes.

(U. S. Dept. Agr.)

DESCRIPTIVE MANUAL 19

Chemical Composition.—Various analyses have been reported
from Washington, D. C., Mississippi, South Dakota and Iowa. The
following analyses are given by Dr. Weems:

a
‘;

Fic. 8-B. Pigeon Grass (Setaria glauca) ; a, portion of leaf showing ligule; b,
spikelet' with bristles; ¢, spikelet; d, spikelet with first, second, and third
glumes; e, spikelet showing flowering glume and sterile glume; f, flower

opened showing stamens and pistil.

ioe ue ae a ea

a

ee Kossuth
Are o| eo |e :
5 oo if
5 + cca +/+.
F .

fe
) ee t= r =
A Ida 2 | 3 R
= : <
~— a .
‘ 5 = Wein : -
. Lm . s
© . . + .
Ue ons ae aq hliatan’.
G °
+ 2 ‘a robwse F- Y
fe » Nb aes| Mar A +
“atin
¢ SN [Aeokusk pies ooe
Hawattdme! ’ :
. +~ .
+

Hig. 8-A. Distribution of Pigeon Grass.

20 WEED FLORA OF IOWA

NATURAL CONDITION

kc g 3
A (S) be 2 8
Date 3 $ Bn ga e3¢
‘ 8 3 2 2A FA) a £f0
= fa 04 q iS) < Z
Lied
£o al lan hres ae ce NS | 80.53 50 | 2.05 | (1.91) | 6.86 | 2.92 | 7.14
WATER FREH SUBSTANCE
| 55 oe | 2.55 | 10.58 | (2.80) | 35.30 | 14.49 | 37.13
FRESH OR AIR DRY SUBSTANCE
Q
ges| 8
wi fe ij o
o im 3s S98 oa
3 S 3 BE ° S83 | 28
es < em is) ¥ Zz <
See (ii) ees oer a ee 8.17 13.40 1.8 31.25 10.53 34.77 6.94
Tenn. (2):
Nearly ripe —----------__ 3.26 Co 3.80 31.77 5.00 47.48. | soe
Washington, D. C. (8): h
Cut July 1, very young| 74.20 2.89 .60 5.59 4.39 1242s |S eeee
Cut July 24, early ;
bloom” 2222s 68.40 2.29 .84 8.14 2.86 VAS SS
WATER FREE SUBSTANCE
S. D. @): ia
ATIC? 8h SOR! 2s Se eee ee 14.59 2.05 34.03 11.47 S87 86h} aoe eee
Tenn, 1(2)s ae eee eee ere 9.04 3.93 32.82 5.16 49°05 || fozeees
Washington, D. C. (8):
Cut July 1, very young|_-_-_-____ 10.80 2.30 21.70 17.00 48, AQia| Meee
Cut July 24, early :
lOO mn! 22 ae |e eee ce 7.30 2.70 25.80 9.00 5 SO | Sears
Mississippij2 22222 eee ees 3| 16.74 Pe TIL

385.04 9.20 S431; | 222 eee

Green Foxtail (Setaria viridis (L.) Beauv.).

Description.—An erect annual from 1-3 ft. high; leaves 4-12 in.
long, with rough margins; greenish, more or less compound eyl-
indrical spikes from 1-5, or even in some cases 6 in. long; bristles
few, much longer than the spikelets; spikelets 14 in. long, the chaff
of second and third glumes as long as the minute chaff of the
fourth glume, the latter being dotted and striate. A single head
produces an enormous number of seeds.

Distribution.—This European grass is common in North Amer-
ica, especially eastward. It is found everywhere in the state, more
particularly in corn fields, gardens, and in vacant places.

Extermination—The same method of extermination should be
used for this weed as for pigeon grass.

DESCRIPTIVE MANUAL 21

Chemical Composition—Green foxtail grown in Pennsylvania
and cut Aug. 11, 1880, analyzed as follows, according to the U. S.
Dept. Agr. (Chem. Comp. Am. Grasses, 1884, p. 125) :*

GREEN FOXTAIL
{Seraria viridis (ferent }

Fie. 9. Green Foxtail (Setaria viridis). Common in corn fields, waste places.
(After Clark and Fletcher.)

*Jenkins and Winton: Bull. Off. Exp. Sta. 11: 71.

re WEED FLORA OF IOWA

Fic. 9-A. Distribution of Green Foxtail.

FRESH AIR DRY MATERIAL

x . . Nitrogen free
Water | Ash | Protein | Fiber | er Fat
14.30 | 6.80 | 7.30 | 18.80 | 50.18 | 2.62
WATER FREE SUBSTANCE
\
| 7.9 | 8.6 21.9 | 58.5 3.1

Bristly Foxtail (Setaria verticillata (.) Beauy.).

Description—An annual from 1-214 ft. high with leaves from
2-7 in. long, somewhat narrower than in the preceding, from 14-14
in. wide; sheaths smooth, rough on the margins and veins; spike
. cylindrical, from 1-414 or 5 in. long, composed of short cylindrical
clusters; bristles short, a little longer than the spike, single or in
pairs, barbed downward; seeds small, greenish, 14 line long,
minutely cross-striated and wrinkled.

Distribution—This European grass is more common eastward
and southeastward. It is of comparatively recent introduction into
Iowa, being most abundant in the southeastern part, though also
occurring at such points as Marshalltown, Ames, Sioux City and
Council Bluffs. It is found in gardens and in the streets.

Extermination —tThe foxtails are annuals and hence it ought to
be an easy matter to destroy them. They produce an enormous
amount of seed. Mr. G. M. Lummis estimated that a good sized
plant of Setaria viridis had 2,500 to 5,000 seeds, and Setaria glauca
1,000 to 5,000; this being the progeny of a single seed.

DESCRIPTIVE MANUAL 23

Fly
Fic. 10. Bristly Foxtail (Setaria verticillata) ; a, spikelet showing bristle and
glume; b, spikelet.
(U. S. Dept. Agr.)

Wic. 10-A. Distribution of Bristly Foxtail.

24 WEED FLORA OF IOWA

Where these grasses are so abundant the ground becomes thickly
covered. Dr. Beal of the Michigan Agricultural College has found
that the seed retains its vitality for a considerable length of time.
After six, years twenty-one seeds out of fifty germinated. The
seeds of all three species are much more tenacious when young than
when older. The ground is covered so thickly that only a few of
the plants are destroyed. Covering up with soil or exposing the
roots to the sun is effective.

Fic. 11. A weedy cornfield: Foxtail, Smartweed, etc. Such a weedy field ma-
terially decreases the yield of corn. Notice how the weeds have crowded
out the corn.

(Photographed by Pammel.)

Clark and Fletcher recommend as follows: ‘‘The only way to
eradicate this weed is to mow it or hoe it out before it goes to
seed. Anything which prevents it from going to seed for a number
of years will eradicate it in time. Most ground, however, is so full
of the seed that it takes a number of years of conscientious work to
exterminate it.

DESCRIPTIVE MANUAL 25

Fic. 12. Foxtail and other weeds in back dooryard. Too many such places
in Iowa.
(Photographed by Charlotte M. King.)

Sandbur (Cenchrus tribuloides L.).

Description.—Annual, with spreading or ascending, much-
branched culms, rarely 1 ft. high, somewhat compressed ; leaves flat
or simply folded, about 6 in. long, acute, finely serrulate along the
margins; sheaths generally much exceeding the internodes, hairy
along the margins and at the throat; burs containing the spike-
lets, 6-20, nearly globose, covered with strong and more or less
pubescent, barbed spines, which become very hard at maturity and
readily fall off.

Distribution—Common in eastern North America, sandy
shores of lakes, streams, and sandy soil. In Iowa, common on
Muscatine Island, railroad embankments, gravel knolls, and in
Polk, Clinton, Muscatine, Scott, Woodbury, Linn, Jackson, John-
son, Dubuque, Webster and Black Hawk counties.

Extermination.—This weed is easily exterminated by cultivation.
The roots are fibrous and exposure to the sun for a short time will
destroy the weed. .

26 WEED FLORA OF IOWA

Fic. 13. Sandbur (Cenchrus tribuloides). Common on sandy soils, gravel
k t

s, ete.
(Photographed by Hart.)

Fic. 13-A. Distribution of Sandbur.

DESCRIPTIVE MANUAL 27

Vanilla or Hoiy Grass (Hierochloe borealis Roem. and Schultes).

Description.—A perennial grass with creeping, fragrant root-
stocks, 144 ft. high; panicle somewhat one-sided, 2-5 inches long;

Fic. 14. Holy Grass, Vanilla Grass (Hierochloe borealis). Common in north-
western and northern Iowa in low grounds. Creeping ‘roots’? something like
Quack Grass, but with the odor of vanilla.

(Photographed by Colburn.)

Wie. 14-A. Distribution of Holy Grass.

28 WEED FLORA OF IOWA

spikelets chestnut colored, 3-flowered; the 2 lower flowers stamin-
ate with 3 stamens; the upper flower perfect, short pedicelled,
awnless, with 2 stamens.

Distribution.—Common in the north. Frequently a trouble-
some weed in Minnesota and northwest territory. Common only as
a weed in a few of the northwestern counties of Iowa.

Extermination.—This weed can be exterminated by giving a
shallow plowing after the crop has been removed and stirring the
soil thus exposing the root-stocks to the action of the sun.

Poverty Grass (Aristida dichotoma Michx.).

Description.—A_ slender, tufted, branched annual from 12-24
inches tall; spikelets in narrow, striate, simple or compound spikes;

Fic. 15. Poverty Grass (Aristida dichotoma). Common in dry, sterile soil.
a, lower or empty glumes of a spikelet; b, a floret showing awns, middle
one coiled.

DESCRIPTIVE MANUAL 29

Fie. 15-A. Distribution of Poverty Grass.

empty glumes nearly equal, longer than the flowering glume,
equaling the small lateral awns; the awns unequal, the long mid-
dle awn horizontal, but soon becoming reflexed.

Distribution.—Poverty grass is common in dry, sterile, or clay
soil in southeastern Iowa.

Extermination.—The fibrous roots of the plant are easily killed
by cultivation.

Long-awned Poverty Grass (Aristida tuberculosa Nutt.).

Description—A rigid, much-branched perennial, 12-18 in. tall;
panicles simple, 4-7 in. long; erect, rather distant branches, the
lower in pairs of which one is short and few-flowered, the other
elongated and many-flowered; empty glumes, nearly equal, awn-
pointed, flowering glume, twisted above to division of awns; awns
nearly equal, articulated with glume.

_ Distribution—Common gravelly knolls and sandy soil, northern
and eastern Iowa.

Extermination—Succumbs readily to cultivation.

30 WEED FLORA OF IOWA

Fic. 15-B. Poverty Grass (Aristida tuberculosa). Common in gravelly and
sandy fields.

(Photographed by Colburn.)

Nimble Will (Muhlenbergia schreberi J. F. Gmel.).

Description—A low, ascending perennial with slender, much-
branched, wiry culms, 1-2 ft. long; sheaths smooth, pilose at the
throat; ligule very short; leaf-blade 1-2 lines wide, 1-4 in. long,
scabrous on both sides; panicles 3-7 in. long, slender, branches
erect, rather densely flowered; spikelets 1 line long, equaling or
exceeding the pedicels; empty glumes minute, unequal, the lower
sometimes obsolete; flowering glume narrowly lanceolate, pilose
near the base, scabrous on the nerves above, terminating in a
slender straight awn, 1-2 lines long; palea equaling the glume.
Shaded thickets.

Fic. 16. Nimble Will (Muhlenbergia schreberi) ; a, sheath and base of leaf; b, d,
glumes; c, lower part of rachilla; e, flower. In southern Iowa.
(Prawn by C. M. King.)

32 WEED FLORA OF IOWA

Distributton.—Nimble Will was originally confined to southeast-
ern Iowa. It has spread northward along the Mississippi, where it
is now abundant as far north as Dubuque. It occurs also in central
Iowa in Story, Boone and Webster counties and is spreading. The
grass is of little economic importance.

Extermination.—This weed is much more difficult to destroy than
the other nimble weeds illustrated. The root-stocks spread more or
less horizontally and are large and fibrous. Give a thorough culti-
vation, exposing the roots to the sun, and then follow with some
leguminous crop. This weed is apt to be abundant in pastures.
Here there is no other method of treatment than to get blue grass
and white clover into the pasture.

Mexican Drop-seed Grass {Muhlenbergia mexicana (L.) Trin.).

DescriptionAn upright or ascending, usually much-branched
perennial 1-3 ft. high, with a scaly, creeping root-stock; numerous
flat leaves and contracted, densely-flowered panicles; sheaths longer
or shorter than the internodes, smooth; ligule 1% line or less long;
leaf-blades 1-3 lines wide, 2-7 inches long; spikelets about 1 line
long on very short pedicels; empty glumes nearly equal, acuminate-
pointed about the length of the floral glume (a little shorter or
sometimes a little longer), scabrous on the keel; flowering glume
lanceolate, acute or mucronate-pointed, 3-nerved, pilose near the
base and on the callus; palea a little shorter than its glume, very
acute.

Distritution—Widely distributed in eastern North America,
from Canada to Minnesota, South Dakota, Iowa, Nebraska and
Missouri. Common everywhere in waste ground in Iowa, espec-
lally in Polk, Story, Pottawattamie, Webster, Crawford, Black
Hawk, Calhoun, Clinton, Linn, Jasper, Lee and Dubuque counties.

Extermination—The character of the ‘‘roots’’ is so different
from that of the roots of quack grass and the other perennial weeds
that it is not difficult to exterminate. The ‘‘roots’’ of this weed and
the allied species are more or less clustered. In an experiment con-
ducted to exterminate it we found that by giving a shallow plow-
ing of four or five inches and harrowing to expose the ‘‘roots’’ to the
. sun, they were killed, no growth making its appearance during the
rest of the season. Of course this is not effective during rainy
weather.

DESCRIPTIVE MANUAL 33

Fic. 17. Mexican Drop-seed Grass or Nimble Will (Muhlenbergia mexicana).
Common in orchards, gardens and fields; sometimes called Orchard Grass,
but incorrectly also called Turkey Grass because of the thickened clustered
“roots.” (ot) de ug

(Photographed by Hart.)

Fic. 17-A. Distribution of Mexican Drop-seed Grass.

oo
nS

WEED FLORA OF IOWA

Chemical Composition—Mexican drop-seed grass has been
chemically investigated by the Dakota, Tennessee and Iowa sta-
tions. The Iowa analyses were made at 7 different times between

April 29 and July 20 with the following results.
tent varies greatly as does the protein content.

NATURAL CONDITION

Sample | Date
|
i afl wean 4-29-1896
Deane monn 5-14-1896
E Mitaneeres.. 5-28-1896
1 tae oe 6 8-1896
Ease ait 6-18-1896
6) ee 6-29-1896
7 ae | 6-20-1896

Height| Water} Fat penn
4-12 84.82 .88 3.5L ( 2.738)
20-23 73.28 1.21 Fp be) ( 3.78)
26-29 82.95 54 2.86 (.1.96)
36-38 77.46 .79 2.41 ( 2.14)
38-39 73.37 -81 2.13 ( 2.10)
39-40 58.77 1.49 3.22 ( 2.60)
48-49 81.98 .53 1.48 ( 1.09)

Ey aes
SRYSSRAE

a

The water con-

Nitrogen

free
extract

Fic. 18. Mexican Drop-seed Grass (Muhlenbergia mexicana); a, b, spikelets.

DESCRIPTIVE MANUAL 35
WATER FREE SUBSTANCE
; ay Nitrogen
Sample Date |Height| Water| Fat |Protein|4!bumin-| Crude} 4.4 free
: oids Fiber .

extract

Ren
Beg ee ae 5.8! 23.16 (17.09) 24.36 13.41 30. 26
Ba a NA ae RRR) mes eo ee ae 4,52 19.17 (14.17) 28.90 10.38 37.03
Bee eA ATEN Teh Oo 3.10) 16.77 | (l.46) | 37.72 11.48 30.94
ce etl a ee ea Se I SI Rh iV epee 3.49 10.70 ( 9.52) 5.94 9.27 40.60
Fa rae eR CRIS RE a |S aes 3 03 8.00 (G88) 33.83: 9.67 45.47
eee Set en Ne S| 3.62 7.81 ( 6.30) BRaail 6.40 49|,86
pe se 2.95! 8.96! (6.11) | 32.48 6.16 50.16

Description——A rather stout, upright perennial, with very tough
and densely scaly root-stocks, nearly simple culms, 2-3 ft. high, and
densely flowered panicles, 2-4 in. long; spikelets 2-3 lines long, the
long, acuminate-pointed outer glumes nearly equal and exceeding
the very actite flowering glume, which is densely bearded at the

base.

Fic. 19. Marsh Muhlenberg, Drop-seed Grass, Wild Timothy, and frequently
ealled Orchard Grass (Muhlenbergia racemosa).
chards, and especially in grain fields in low grounds.

(Photographed by Hart.)

Common in gardens, or-

36 WEED FLORA OF !OWA

Fic. 19-B. Marsh Muhlenberg (Muhlenbergia racemosa) ; a, spikelet with long
acuminate-pointed outer glumes; b, flowering glume, bearded.

DESCRIPTIVE MANUAL 37

Distribution.—Widely distributed in eastern North America, es-
pecially in meadows from Canada and New England, to New Jer-
sey, west to the Rocky mountains, Iowa to Missouri.

Extermination.—The clustered root-stocks are easily destroyed
by exposing to the sun. Use the same methods as IESE given for
the Mexican drop-seed grass.

Sheathed Rush Grass (Sporobolus vaginiflorus (Torr.) Wood.).

Description.—A slender, caespitose annual, 1-3 ft. high, with
narrow, short leaves, and simple, few-flowered, terminal and axil-
lary, spikelike panicles which are about 1 in. long, and mostly en-
closed in the somewhat inflated leaf-sheaths; spikelets 1-2 lines long.

Fic. 20. Drop-seed or Rush Grass (Sporobolus vaginiflorus). Common in sandy
fields, lawns and gravelly soil.
(Photographed by Hart.)

38 WEED FLORA OF IOWA

Fic. 20-A. Distribution of Sheathed “Rush Grass.

- Distribution—Common in sterile fields and waste places from
New England to Wisconsin, South Dakota, and Jowa, and south-
ward. Especially common in pastures, lawns, and along roadsides ~
in Iowa. Story, Polk, Boone, Clinton, Crawford, Carroll, Web-
ster and Emmet counties.

Extermination.—This annual is easily exterminated by culti-
vation. The small fibrous roots succumb readily when exposed to
the sun. Do not permit the plant to form seed.

Small Rush Grass. (Sporobolus neglectus Nash).

Description-—Culms 6-12 in. high, erect, from a usually decum-
bent base, slender, often much-branched, smooth and glabrous;
sheaths about half as long as the internodes, inflated; ligule very
short; leaves 1 line wide or less at the base, smooth and glabrous be-
neath, scabrous and hairy near the base above, attenuate into a
slender point, the lower elongated, the upper 1-3 in. long, setaceous;
terminal panicle 1-214 in. in length, usually more or less included in
the upper sheath, striate; lateral panicles enclosed in the sheaths;
spikelets about 114 lines long, the outer scales acute, the lower one
shghtly shorter, third scale acute, glabrous, a little longer than the
second, and about equaling the acute palet.

Distribution.—Oeccurs from New Brunswick to Virginia, Wiscon-
sin, Iowa, South Dakota and Texas. In similar situations with the
preceding species. Along beaten paths, pastures and roadsides.

DESCRIPTIVE MANUAL

Fig. 21. Drop-seed or Rush Grass (Sporobolus neglectus). Pastures,

‘fields.
(Photographed by Hart.)

i
| SS 4} — 4 }.- —-- =. -. —— fe
| Ms el eische

A
| } OBren head SS
| + Ie

[Bu Har
+
“%G = ES
y 5 + bug.
toa bent
° +
tne] :
saul ae mes e
{ . s Re
zs Chats
\ + ® » ne
es) +
Heokish ps
wath mre
? +
alt

i Fic. 21-A. Distribution of Small Rush Grass.

39

sandy

Extermination. == his weed should be treated in the. same man-

ner as the preceding species.

40 WEED FLORA OF IOWA

Wild Oats (Avena fatua L.).

Description.—An erect, glabrous annual, 3-5 ft. high, with flat
leaves and spreading panicles of large, oatlike, nodding spikelets;

WILD OATS

(Avena Fatua «)

Fic. 22. Wild Oats (Avena fatwa). In oat and grain fields, northeastern Iowa.
(After Clark and Fletcher.)

DESCRIPTIVE MANUAL 41

Fig. 22-A. Distribution of Wild Oats.

spikelets 2-4-flowered, with empty glumes 34 to 1 in. long, and
pubescent, flowering glumes 6-9 lines long, awns nearly twice as
long as the spikelets..

Distribution—Common in Canada, rare in eastern North Amer- —
ica, abundant in the northwest, Wisconsin, Minnesota, Dakotas,
Rocky mountains and Pacific coast. In a few counties in northern
and northeastern Lowa.

Extermination.—largely spread with oats seed. Use only clean
oats seed. It succumbs readily to cultivation. Practice rotation of
erops. Corn or some other cultivated crop should follow oats. The
oats field should be prone into meadow. Clover and timothy are
good rotations.

Crowfoot Grass, Wire Grass (Eleusine indica Gaertn.).

Description—aA coarse, tufted annual, with erect or spreading
stems, 6-24 in. high, and digitate spikes; sheaths compressed and
sparingly ciliate; leaf-blade long and narrow, both surfaces glab-
rous, or the upper scabrous and thinly hairy; spikes 5-7, 2-4 in.
long, digitate at the apex of the culm, often with 1 or 2 lower down,
-widely spreading; spikelets closely imbricated, 114-2 lines long, 3-6-
flowered ; glumes obtuse, the first small and 1-nerved; seeds rugose,
enclosed within a thin, loose pericarp.

Distribution.—Naturalized from the Old World. In waste
ground, streets, yards, from New England to Iowa, and common
southward. In Iowa, in Marshall, Scott, Pottawattamie, and Clin-
ton counties.

42 WEED FLORA OF IOWA

Fic. 23. Crowfoot Grass (EHleusine indica). Streets, roadsides, southern and
southeastern Iowa.
(Photographed by Hart.)

Kassuth

Fic, 23-A. Distribution of Crowfoot Grass.

DESCRIPTIVE. MANUAL | 43

Extermination.—Cultivation readily destroys the weed. When
it appears in the lawn it must be pulled up or the grass cut closer
to the ground. .

Chemical Composition—The chemical composition of Yard
grass, Crowfoot, Crab grass, Wire grass (Hleusine indica): (Cut
Aug. 11, 1880; grown in Pennsylvania) according to U. S. Dept.
Agr., Chem. Comp. Am. Grasses, 1884, p. 125, is as follows :*

FRESH OR AIR DRY MATERIAL

: A Nitrogen free
«Water | Ash | Protein | Fiber | eaaieteh Fat
14.30 | 19.81 | 10.14 | 19.63 : 43.33 | 2.79
WATER FREE SUBSTANCE
: :
| 11.5 11.8 | 22.9. 50.5 3.3

Candy Grass (Eragrostis major Host).

Description.—A rather showy, much-branched annual, with erect
or ascending stems, 6 inches-2 or 3 feet high; sheaths striate, smooth,
~ hairy at the throat; ligule a fringe of short hairs; leaf-blade flat,
3-10 in. long, 1-3 lines wide, somewhat scabrous on the upper sur-
face; panicle elliptical or oblong, the branches usually spreading,
flowered, 2-8 lines long, 114-2 lines broad, spikelets ovate to linear,
7-40 empty glumes nearly equal, ovate, obtuse, prominently nerved,
and scabrous on the keel; palea ciliate on the keels.

Distribution Eragrostis major is a weedy grass in all parts of
the state; introduced by the earliest settlers.

Extermination.—This weed is easily exterminated by cultivation.
The best way to kill it is to cultivate corn in the soil and follow
with small grain.

*Bull Off. Exp. Sta. 11; compiled by Jenkins and Winton.

44

Fic. 24.

WEED FLORA OF IOWA

Candy Grass, Stink Grass (Hragrostis major). Common in gardens,
fields and roadsides.
(Photographed by Colburn.)

Fic. 24-A. Distribution of Candy Grass.

el a a

DESCRIPTIVE MANUAL 45

Southern Spear Grass (Hragrostis pilosa (L.) Beauv.).

Description.—An annual, 5-18 in. high, with erect or ascending
stems diffusely branching near the base; sheaths pilose at the throat,
otherwise smooth, leaf-blade 1-7 lines long, 14-114 lines wide, con-
duplicate when dry; panicle oblong-lanceolate to pyramidal, 3-8
or 12 in. long, the widely spreading primary branches solitary, or
2-3 together, the axils not pilose; spikelets narrow-lanceolate, 2-414
lines long, 3-15-flowered, appressed to the branches, nearly equal-
ing or exceeding their capillary pedicels; empty glumes ovate, acute,
scabrous on the keel, the longer one about 1% line in length; flower-
ing glume broadly ovate, obtuse, distinctly 3-nerved, scabrous on the
keel, about 34 line long; palea scabrous on the keels; grain oblong.

Fic. 25. Spear Grass (Hragrostis pilosa). Roadsides, streets, fields, etc.
(Photographed by Quade.)

46 WEED FLORA OF IOWA

Hic, 25-A. Distribution of Spear Grass.

Distribution.—This grass is widely distributed in eastern North
America in waste places, roadsides, and sometimes in fields, espe-
cially in sandy soil. New England to Wisconsin, Minnesota and
southward.

Extermination.—Suceumbs readily to cultivation.

Soft Chess (Bromus hordeaceus L.).

Description.—An erect, usually slender, pubescent annual, 1-3
ft. high, with flat leaves, and contracted panicles, 1-3 in. long; spike-
lets 3-8-flowered, 14-1 in. long, with pubescent glumes, the flower-
ing ones 314-41 lines long, obtuse and awned; awns 3-4 lines long.

Distribution.—Frequent in waste places, roadsides, and fields,
from Canada to Virginia and Rocky mountains. Most abundant
of the brome grasses in Iowa, Story, Boone and Polk counties.

Extermination.—Succumbs readily to cultivation. Fields are
largely sown from plants growing in waste places. Therefore, cut
down the weed along roadsides and in waste places.

Chemical Composition.—Chemieal analysis made at the experi-
ment station at Ames by Dr. Weems shows the following results:

47

DESCRIPTIVE MANUAL

Soft Chess, Annual Brome Grass (Bromus hordeaceus). Common in

Fic. 26.

fields and waste places.
(Photographed by Colburn.)

Fic. 26-A. Distribution of Soft Chess.

48 WEED FLORA OF IOWA.

NATURAL CONDITION

é aoe Nitrogen
Sample Date |Height| Water| Fat |Protein Pee Fee Ash free
: extract
i ape eae Sr 4-24-1896 5.10 85.07 1.41 4.19 ( 3.23) 3.18 1.92 4.23
A Oe See 5- 4-1896 18-18 87.29 .94 2.14 ( 1.38) 3.38 1.83 4.45
BS aeseo eee 5-11-1896. 18-24 79.37 85 2.62 ( 2.50) 5.47 2.19 9.50
ieee aera a 5-20-1896 |__--- eal G0L635 .78 2.96 ( 2.10) 6.42 2.05 7.16
gee ce, 6— 1-1896 | 30.32 71.41 .85 3.52 ( 3.08) 10.01 2.54 11.67
WATER FREE SUBSTANCE

Ds oe | se ee | ee | 9.46 28.05 (26.61) 21.31 12.89 28.26
9 a Pon Ci Ramin | DRA DIE as 7.43 | 16.83] (14.80) | 26.61] 14.38 34.75
By Laem eC ae OS SAI ald a 4.10 12.71 (12.12) 26.54 10.64 46.01
A eX ee ee ee ee ma (FE | ee 4.08 15.30 (10.§8) 33.18 10.61 36.83
5 2.95 12.30 (10.76) 35.01 8.91 40.83

This grass is very nutritious in its young condition. The protein
varies from 2.14 per cent to 4.19 per cent, but there is a seeming
variation with different plants found under different conditions.

Chess, Cheat (Bromus secalinus L.).

Description.—An erect annual, 2-3 ft. high; culms smooth or
pubescent at the nodes; sheaths striate smooth, scabrous or some-
times pilose; ligule short, blunt; leaf-blade 6-12 in. long, rather
broadly linear, smooth beneath, more or less rough and pilose on
the upper surface; panicle 4-8 in. long, erect, the more or less com-
pound branches, spreading, even in fruits; spikelets 6-10 lines long,
oblong ovate, turgid, 6-12-flowered, pendulous in fruit, empty
glumes oblong lanceolate, acute, the first 3-5, the second 7-nerved ;
flowering glumes ovate-oblong, obscurely 7-nerved, smooth or mi-
nutely downy along the margins and toward the apex, becoming
nearly cylindrical in fruit; palea obtuse, strongly nerved; nerves
toothed or frmged with distant bristles.

Distribution—Common wherever wheat is cultivated and some-
times in waste places, from the Atlantic to the Pacific. At one time
common in many parts of Iowa, but now occurring sparingly ex-
cept where wheat is cultivated.

Extermination.—uUse clean seed and sow in clean soil. The weed
succumbs readily to cultivation.

Chenucal Composition.—The common Bromus secalinus analyzed
at the Iowa station by Weems shows the following analysis.

DESCRIPTIVE MANUAL

‘CHESS or CHEAT

BroMus Secs

AOS Sh}

Fic. 27. Cheat or Chess (Bromus secalinus) :
(After Clark and Fletcher.)

In grain fields.

49

50 WEED FLORA OF IOWA

Wok oCrecr !
rmaseesun

VL SIT
at
Coe Leb Bees

Fic. 27-A. Distribution of Cheat or Chess.

NATURAL CONDITION.

é Bs

= = asa eet a OS

Sample ® cs 2 £ 3c ss £5

3 a 3 = ° 26 3g ee Ene a

a ca = ey Ay < 6) <q |Z"
iy te eee re 5-20-1896 | 25-30 | 79.22 | 1.99 | 2.74 (56) | 9.15 | 2.21 4.59
OD, Loni nto isn) Pabaale3 | e-y)) | ase |) Ie | 3.23 | (2.49) | 22.88 2.64 | 14.01
WATER FREE SUBSTANCE

igh Bee ee “SE 1A Poh NR Eom RNa let SE 9.59 | 13.17 { (9.42) | 44.04 | 10.63 | 922.57
De RI Rc AE ES er et ea a Re 3.57 9.66 | (7.44) | 37.03 | 7.91 41.83

There is considerable nourishment in the nutritive suhstance
when the plant is young, but when old it can not be considered
very nutritious.

Downy Brome Gress (Bromus tectorum L.).

Description —A slender, erect. leafy annual. 7-25 in. high, with
narrow, softly pubescent leaves, and open, nodding panicles, 3-714
in. long; spikelets 5-8-flowered, with unequal, acuminate-pointed,
hirsute, empty glumes, and rough or hirsute flowering glumes, 4-6
lines long; awns 6-8 lines long.

Distribution—Common in waste places, Rocky mountains and
the Pacific coast, Atlantic states, Maine to Iowa. Not abundant in
Towa.

DESCRIPTIVE MANUAL 51

Fic. 28. Downy or Awned Brome Grass (Bromus tectorum).
in streets of our larger cities.
(Photographed by Quade.)

An annual grass

MLA

eG a noma alee —— jaa K a ee
Kossuth SS = a
os aa

reene lor |, | i
Clinton
0es| Mon Ss

i Hpbscatne)
Keokuk :

| G
Fage Decatur |

Fig. 28-A. Distribution of Downy Brome Grass.

52 WEED FLORA OF IOWA

Extermination.—Care should be used in destroying packing ma-
terial. In the few localities in which this weed occurs in Jowa, it
has come from packing material. It succumbs readily to cultivation.

Poison Darnel (Loliwm temulentum L.).

Description.—An annual, with smooth, stout culm, 2-3 ft. high;
sheaths scabrous; ligule short, spike 6-12 in. long; spikelets 5-7-
flowered ; empty glumes sharp pointed, as long as the spikelet, flow-
ering glumes turgid, awned or awnless, shorter and broader than
in L. perenne.

Distribution.—Introduced from Europe; naturalized in eastern
North America and quite abundant on the Pacific coast; found in
many counties in Iowa.

Fic. 29. Poison Darnel (Loliwm temulentwm). Common in oat and wheat
fields in northern lIowa.
(Photographed by Hart.)

DESCRIPTIVH MANUAL 53

Fic. 29-A. Distribution of Poison Darnel.

Extermination.—Sow clean oats or wheat. The weed succumbs
readily to cultivation.

Quack Grass (Agropyron repens Beauv.).

Description—aA perennial with a many-jointed, creeping rhi-
zome (root-stock) ; culm from 18 in-4 ft. high, bearing numerous
leaves from 5-12 in. long, and from 14-14 in. wide; margins rough,
very smooth beneath, slightly hirsute above; spikes 6-12 in. long,
erect ; spikelets on opposite sides of a jointed and channeled rachis,
pubescent on the margin, erect, 4-8-flowered ; lower or sterile glumes
acute or short-awned, prominently 5-7-nerved, flowermg glumes
smooth ; palet acute or somewhat rounded, smooth or shghtly pube-
scent.

The Western Wheat Grass (Agropyron smithti Rydb.) is closely
related to quack grass. The plant is glaucous; leaves are rigid,
bluish green in color, scabrous on the margin, edges rolling in;
spikelets 7-13 flowered, in a thicker spike (‘‘head’’) than quack
erass ; running root-stocks (‘‘roots’’). Common along railways
and in northwestern Iowa. This plant is not considered a weed.
It may be used to plant railway embankments.

The Slender Wheat Grass (Agropyron tenerum Vasey) produces
a slender long head, greenish in color, running roots absent.

Distribution.—This grass is common and widely distributed from
Manitoba, Minnesota, and western Iowa to Arkansas and Texas.
In lowa it has. been found and reported in the following localities:
Afton Junction, Ames, Armstrong, Iowa and Minnesota line nea’
Ceylon (Minnesota), Elmore, Hampton, Harcourt, Keokuk, Des

54 WEED FLORA OF IOWA

Moines, Mason City, Nora Springs, Ontario, Pilot Mound and in
Hamilton county. ‘It is especially common in the loess soil from

COUCH QUACK on SCUTCH GRASS

2) Sens + )

Fic. 30. Quack Grass, Quick Grass, Scutch Grass (Agropyron repens). Fields,
waste places, around elevators, meadows, roadsides and pastures, especially
northern Iowa.

(After Clark and Fletcher.)

DESCRIPTIVE MANUAL 55

Agr
(one canna
arse se .
VCE RESET ke [SS
eee

Fic. 30-A. Distribution of Quack Grass.

Carroll to Lyon county and eastward and northward and is found
extensively along railroads. It is found in northern lowa from
Mississippi to Missouri rivers, probably in every county.

Extermination.—With reference to the extermination of quack
grass, experiments made at Ames indicate that quack grass can be
exterminated. When it covers considerable areas it may be neces-
sary to summer fallow. The land should be plowed in August when
the small grain crop has been removed. The first plowing should
be shallow, not more than two or three inches deep. Then harrow
with a common drag. This will expose a large number of the
‘‘roots’’. If the grass appears again, run over the field with a disc
and drag. This should be continued for the remainder of the sea-
son. In the spring plow the soil six or seven inches; drag and ex-
pose the ‘‘roots’’. The field should be kept free from weeds of all
descriptions during the entire growing season. It may be neces-
sary to go over the field at least once a week to get all of the quack
grass. Where land brings as much per acre as in Iowa, no farmer
can afford to leave his land fallow. The field should be given the
same treatment in the fall and early spring as outlined above. Sow
thickly with one of the following crops: Sorghum, Millet, Buck-
wheat, or Rye. These crops will not entirely kill the quack grass but
will reduce its vitality to such an extent that what remains may be
easily treated by plowing six or seven inches deep in the fall, follow-
ing with a harrow. With sorghum very little quack grass will re-
main. Experience has shown that quack grass is shallow-rooted and
that the roots will not grow readily through the soil beyond a depth
of six inches.

56 WitED FLORA OF TOWA

Fic, 30-B. Western Wheat Grass (Agropyron smithii). Common along rail-
roads and in northwestern Iowa. The distribution of A. smithii is shown in
fig. C and of Slender Wheat Grass (A. teneruwm) in fig. D. a, empty glumes;
b, flowering glumes with flowers.

Fic. 30-C. Distribution of Western Wheat Grass.

DESCRIPTIVE MANUAL 57

The following suggestions for exterminating the weed are made
by Fletcher and Clark: ‘‘Let the plant exhaust its substance in
the production of a hay crop, which should be cut and removed as
soon as the head is formed and before it is in bloom. Plow shallow
and cultivate until the root-stocks have been brought to the surface
by implements that can be forced, after repeated applications, to the
full depth of the furrow. A disc is not satisfactory because the cut-
tings from the root-stocks are difficult to gather and they perpetuate

SS
chell\\ ™
e eset

Fic. 30-D. Distribution of Slender Wheat Grass.

the growth, wherever transplanted. When brought to the surface the
root-stocks should be gathered and burnt or removed. This should
be done at once before the plant has had an opportunity to renew
its growth. For Manitoba, S. A. Bedford recommends plowing up
the couchgrass late in the spring and seeding at once to barley, three
bushels to the acre.”’

Chemical Composition.—V arious chemical analyses have been
made of quack grass. The following were reported by Weems from
material grown in Iowa.

NATURAL CONDITION

~ a cE H 5 8
= a0
Sample 2 % 8 Geis oe oo8
3 o 3 s © 2e Pe ao 1880
Qa q E i A < ‘S) <q |Z
1c, (CHA SC A ee 418-1996 | 48 | 73.96 | 1.15 | 5.13 | (4.57) | 6.13 | 3.14 | 10.49
Ourgnenes Cees 5- 6-1896 | 16.24 | 79.06 181 | 4.41 | (2.47) | 5.66 | 3.11 6.95
SMe ees See 5-20-1896 | 20-30 | 79.56 | 1.51 | 4.64 | (2.11) | 4.96 | 2.09 7.24
[ee B= RS ae 6-1-1996 | 26.28 | 75.84 | 1.47 | 4.23 | (2.04) | 6.68 | 2.66 9.64
Ei oh oes, Ar eS 6-15-1896 | 26-98 | 80.56 | 1.28 } 1.35 | 4.32) | 5.05 ! 2.12 9.64
WATER FREE SUBSTANCE.
Rep OE aon Ge oer Bel ad ee 4.41 | 19.70. (7.57) | 23.55 | 12.08 | 40.26
Oe) Sen fees SS DEFENSE OR BOUIN (ET eI ae) ARS Nm 3.86 | 21.06 |(11.80) | 27.12 | 14.84 | 33.12
Gps cM Oy een [Res Som mea OI ena ga abate 7.37 | 22.71 |(10.34) | 24.98 | 10.24 | 35.40
AS ROLES REV CMER gta oie ts Tae Smear rare 6.08 | 17.52 |( 8.44) | 27.56 | 11.00 | 37.84
fi. VEEL aa UEC Pelee” Ciesla = We Uc (ear eal 6.59 | 6.96 |( 6.80) | 25.97 | 10.93 | 49.55

58 WEED FLORA OF IOWA

It is not as valuable for pasturage as blue grass but it compares
very favorably with timothy in regard to the amount of protein and
nitrogen free extract it contains.

Squirrel-tail Grass (Hordeum jubatum L.).

Description—An annual cr winter annual from 6 in.-2 ft. high,
producing fibrous roots which form solid, compact bunches, leaves
not unlike those of blue grass, but paler in color, from 2-4 in. long,
margins scabrous; flowers in a dense spike from 2-4 in. long, pale
ereen or purplish in color; spike consisting of a number of 1-flow-
ered spikelets, 3 occurring at each joint, 1 being perfect, the other
spikelets awl-shaped, rudimentary, and borne on short stalks, 1
sterile spikelet occurring on each side of the perfect flower, which
bears a long awn; at each joint will be found 6 empty long-awned
glumes spreading at maturity giving to the plant its bristly appear-
ance; when mature, the spike breaks up into joints consisting of the
rudimentary spikelets and a perfect flower, so that each joimt has
one “‘seed,’’ the number of ‘‘seeds’’ in a spike varying from 35-60.
A single cluster of plants may therefore produce from three hun-
dred to two thousand mature ‘‘seeds’’. The plant has a wonderful
capacity for “‘stooling’’. From a single plant as many as forty
spikes may be produced, and the number no doubt often exceeds this.

- Distribution —Squirrel-tail grass, originally, was abundant in the
vicinity of alkali lakes and along the borders of streams west of
Missouri river. It also occurred sparingly on the North Atlantic
coast; now, however, it is common across the continent. In: Iowa it
is abundent3 in all parts of the state not only in pastures but in mea-
dows, fields and gardens.

Extermination.—Squirrel-tail or wild barley is a most pernicious
weed along the roadsides and in pastures and meadows; pernicious
because it not only prevents the growth of the better grasses but 1s
injurious to live stock. As this weed is most common in the pas-
ture, the best way to treat it is to mow the pasture before the grass
has matured its seed: Since this weed is an annual, or winter an-
nual, this would effectively dispose of the plant were it not for the
fact that the seed is blown in from neighboring fields and roadsides.
Cultivation-will readily destroy the weed and where it is abundant
in fields shallow cultivation followed by-the disk and harrow should
be effective. : i Bee

DESCRIPTIVE MANUAL” 59.

Clark and Fletcher, in regard to exterminating this grass, which
in Canada is known as Skunk-tail Grass, say: ‘‘There is no diffi-
culty in eradicating this grass from any land which can be plowed,

Fic. 31. Squirrel-tail Grass or Wild Barley (Hordeum juvatum). Meadows,
oh . pastures and roadsides.
(After Clark and Fletcher.)

60 WEED FLORA OF IOWA

Fic. 31-A. Distribution of Squirrel-tail Grass.

as the usual method of breaking in June will destroy it. It gives
most trouble in waste places where it ripens its seed, which is spread
abroad in every direction by wind and water. It grows freely about
the edges of hay sloughs on the prairie and is generally ripe before
the hay is cut. The remedy in this case would be cutting before the
seed is formed.’’

Fic. 32. Squirrel-tail Grass or Wild Barley (Hordewm jubatuwm). Widely dis-
tributed in Iowa pastures, roadsides, etc.
(Photographed by Charlotte M. King.)

Chemical Composition.—Analyses have been reported from Iowa
and South Dakota. The following report is by Weems from Iowa.

DESCRIPTIVE MANUAL ~ 61

NATURAL CONDITION.

4 a 3
py u A a 5 Boece
Sample 2 ic 2 2 EZ 32 o¢s
, = oO 8 3 2 20 ps G BHO
Qa se es cy 3 = ‘S) “_ | %
iy a ee aS 5-20-1896 | 10.15 | 80.51 97 | 4.33 | @.CO) | 7.13 | 2.19 4.87
Oe ed pa aa 5-26-1896 | 23.24 | 72.60 | 1.59 | 3.38 | (2.26) | 10.10 | 2.36 91.98
Gna a ae 6-5-1896 | 23.24 | 67.97 .94 | 3.74 | (2.75) | 12.47 | 2.70 | 12.18
Aenea nse! s 6-17-1896 | 21.25 | 54.39 | 1.68 | 5.e0 |( 3.76) | 17.85 | 4.00 | 16.28
|
WATER FREE SUBSTANCE.
ye eae Dae Olen eel WEE OTR hs Ty A ee 4.97 | 22.21 |(15.48) | 36.59 | 11.24 | 24.99
NR PL Se UI SS Fs 5.82 | 12.36 |( 8.62) | 36.90 | 8.46 | 36.46
Q) - cail BUS OE RRO ER S710 2 8 a mal en 2.94 | 11.78 |( 8.57) | 38.92 | 8.43 | 37.93
Ae ef TS ARES PIES 52 | SO 3.69 | 12.71 |( 8.24) | 39.14 | 8.78 | 35.68

Little Barley (Hordeum pusillum Nutt.).

Description —An annual, 4-10 in. high ; culms more or less genicu-
late at the lower nodes; sheaths smooth, the uppermost often in-
flated and enclosing the base of the spike; leaf-blade 1-3 in. long,
usually a little pubescent on the lower surface; spikes narrow, 1-3
in. long; empty glumes rigid, the 4 internal ones of each group di-
lated above the base, those of the central spikelet sublanceolate, all
awn-pointed; outer glumes of the imperfect, lateral spikelets seta-
ceous; flowering glume of the central spikelet awned; awn equaling
those of the empty glumes; florets of the lateral spikelets awnless,
or nearly so.

Distribution—Common in Missouri and Illinois and becoming
plentiful in southeastern Iowa; also in Marshall and Pottawattamie
counties. Common on the plains.

Extermination.—This annual weed is easily destroyed by cultiva-
tion. Comes up abundantly in streets and along roadsides. The
production of seed in such places makes it possible for farm land to
be sown. The plants should be cut to prevent seeding of farms.

Chemical Composition According to the Wyoming Experiment
Station the composition is as follows :*

*Bul. Wyo. Agr. Exp. Sta. 87; compiled by Henry G. Knight, Frank EH. Hep-
ner, Chemists; and Aven Nelson, Botanist. f

62, WEED FLORA OF IOWA

Fic. 33. Little Barley (Hordeum pusillwm). Roadsides, fields. Common in

southern Iowa.
(Photographed by Colburn.)

pny ye
Mitchel)

Kossuth Sa

‘ar =

Fic. 33-A. Distribution of Little Barley.

DESCRIPTIVE MANUAL 63

=o o
So a) 8
B66| 2258
sOs Shima
Z Ee
iWieuter = === -- Beata arene rt hase WEN UE A BEEN RS eee a te oe erie) Meee
ANS, oo Se a Se Se eee el Oe Oe ee ee 9.25 9.82
BGM OIERUEE ACE» sane ees tsi kT oe ee SR ee oe ee eo Res eae ea eee ei 1.88
OTT CLE BLT Ey Tre ee ec en ee A ae eS Mac Oe es Se 31.58 | 33.52
(COAG) SOFR OY yO Se ee eee eh eee en a gee SE re ee eee a ee a ee ee 6.49 6.89
INTROS ene Treenexbha Ct tas 525 oe eee Mo ee ot oe a Bs 45.12 | 47.89

CYPHRACEAE, SHDGH FAMILY.

This family contains few economic plants. The chufas is used as
food for hogs. The papyrus of the ancients, and the so-called
rushes of our ponds belong to this family. Many of the plants grow
in low grounds.

Northern Nut Grass (Cyperus esculentus L.).

Descripticn.—A grasslike plant growing from 1-214 ft. high; with
triangular stems, leafy at the base when young, later leaves termin-
ating the stems; spikes of numerous spikelets with from 12-30 hght
chestnut or straw-colored flowers; scales of the spikelets rough-mar-
gined ; achene longer than broad.

This perennial weed spreads extensively by its underground nut-
like tubers. It is closely related to the Southern Nut Grass (Cys
perus rotundus Li.) and in the north entirely replaces it.

Distribution.—lt is quite generally distributed in the state and
oceurs frequently in North America from New Brunswick to Texas;
common especially in low spots. Being somewhat yellowish in ap-
pearance it is easily recognized.

Extermination.—This weed can be exterminated only by thorough
cultivation. Running the harrow over the field when corn is young
will not exterminate the weed. The little offshoots merely sprout
again giving rise’-to many more plants. Running the cultivator
through the field is. more effective, but not sufficient. In badly in-
fested fields it will ke necessary to use the hoe.

JUNCACEAEH, RUSH FAMILY.

These grasslike plants are related to the lilies. They generally
grow in low grounds and are of little economic importance.

64 WEED FLORA OF IOWA

Fic. 34. Northern Nut Grass (Cyperus esculentus). Corn fields, especially
low grounds. Young plants have a yellowish color. Weed spreads by the
“roots.”

Fic. 34-A. Distribution of Northern Nut Grass. -

DESCRIPTIVE MANUAL 65

Slender Rush (Juncus tenuis Willd.).

Description.—A leafy perennial, wiry stem, 9-18 in. high; leaves
flat or channeled; flowers in panicles, the panicles shorter than the
involucral leaves; flowers green, sepals lanceolate-acute, spreading
in fruit; capsule green; seeds small, ribbed.

Distribution—A. cosmopolitan weed widely distributed in North
America; common along beaten paths and fields, especially in pas-
tures, in every part of Iowa.

Figure 25 Figure 35A

Fig. 35. Wire Grass or Slender Rush (Juncus tenuis). Common in pastures
along roadsides.
(Photographed by Colburn.)

Fic. 35-A. Distribution of Slender Rush.

Extermination.—This weed is not difficult to exterminate by cul-
tivation. Where it occurs in pastures that cannot be cultivated, an
effort should be made to start a leguminous plant like white clover

which will kill out the rush to some extent.
5

66 WEED FLORA OF JOWA

LILIACEAE, LILY FAMILY.

This family contains a number of economic plants like onion, gar-
lic, leek, chives, such cultivated ornamental plants as the lily, lily
of the valley, and hyacinth and some poisonous plants as the colchi-
cum and bunch flower.

Common Bunch Flower (Melanthium virguucum L.).

Description.—Tall, leafy-stemmed plants 3-5 ft. high; leaves lin-
ear, the lower sheathing, the upper similar and sessile; flowers in an
ample panicle, fragrant; perianth of flat segments greenish yellow ;
styles persistent, capsule 3-celled; 8-10 seeds in each cavity.

Distribution.—In low meadows and prairies from New England
to Iowa river basin, Minnesota, Texas and Florida. Common only
in eastern central Iowa to the Missouri line.

Fic. 36. Bunch [Flower (Welanthium virginicum) In meadows, eastern and
scuthern Iowa. Poisonous.
(Photo Gardner.)

DESCRIPTIVE MANUAL 67

Mitchell\| \. |
ossuth

Fic. 36-A. Distribution of Bunch Flower.

Extermination.—This weed is common only in native meadows
It is killed when these meadows are broken up and cultivated.

Wild Onion (Allium canadense L.).

Description.—A perennial herb, with small scapose bulb; bulb
coat somewhat fibrous; flowers umbellate, umbels densely bulbifer-
ous; perianth of 6 divisions which are narrowly lanceolate, as long
as the 6 stamens or longer ; capsule 3-celled, not crested ; seeds black.

Distribution Common in moist meadows in many parts of Iowa:
Boone, Story, Marshall and Polk counties; from New Brunswick to
Wisconsin, Texas and Florida.

Extermmation.—This weed is common in native meadows, seldom
persists like the wild garlic (Allowm vineale) of Europe in cultivated
fields; thorough cultivation of the field with a plow and disk and
-eultivator will destroy the weed.

DICOTYLEDONEAE, DICOTS.

Stem formed of pith wood and bark; between the bark and wood,
the cambium layer an annual ring of wood formed each year; leaves
netted veined; flowers generally on the plan of five; embryo with a
pair of cotyledons. Rose, pigweed, potato, bean, clover, Russian
thistle, horse nettle, Canadian thistle belong to this division.

68

WEED FLORA OF IOWA

Fic. 37. Wild Onion (Allium canadense).
(Photographed by Charlotte M. King.)

aan ne rr

Michell

Fie, 37-A. Distribution of Wild Onion.

DESCRIPTIVH MANUAL 69

' URTICACEAE, NETTLE FAMILY.

This family in the large sense contains such economic plants as
the fig, india rubber tree, hemp, hop, and such trees as the hackberry
and elm.

Nettle (Urtica gracilis Ait.).

Description.—A perennial, stinging herb from 2-6 ft. high; spar-
ingly bristly; leaves ovate-lanceolate, sharply serrate, with long
petioles, 3-5-nerved sparingly pubescent, petioles usually bristly ;
flowers inconspicuous, paniculate, dioecious or of staminate and pis-
tilate flowers; achene compressed, inclosed by the persistent calyx.
Hairs multicellular at base, urticating.

Fic. 38. Stinging Nettle (Urtica gracilis). Common along. fences and in waste
places. a, stinging hairs of plant.
(Photographed by Colburn. a drawn by Charlotte M. King.)

70 WEED FLORA OF IOWA

Fic. 38-A. Distribution of Nettle.

_ Distribution.—Eastern Canada to Wisconsin, Minnesota, central
Canada and Louisiana; found along roadsides, borders of thickets
and woods; occasionally in gardens and waste places especially in
eastern and southern lowa.

Externunation.—The perennial root stocks make this weed quite
persistent and difficult to destroy, because the weed often occurs in
inaccessible places along fence-rows; however, persistent cultivation

will exterminate the weed.
Chemical Composition.*

FRESH OR AIR DRY {ATERIAL.

s < Nitrogen free
Water | Ash | Protein | Fibe | Se aeh Fat
82.44 | 2.30 | 5.50 | 1.96 | 7.13 | 0.67

WATER FREE SUBSTANCE,

[| ae | a)

Hemp (Cannabis sativa L.).

Description.—A rough, stout, dioecious annual, 3-10 ft. tall;
inner bark of tough fibers; leaves digitate, of 5-7 linear-lanceolate,
coarsely toothed leaflets, the upper alternate; flowers green; stam-
inate, in compound racemes; pistillate, in erect spikes, each con-
sisting of a calyx of a single sepal folded around the ovary and 2
filiform stigmas; fruit an achene; endosperm fleshy; embryo
curved.

*Compiled by Jenkins and Winton: Bull. Off. Exp. Sta. 11.

(iat

DESCRIPTIVE MANUAL

Ss
Dre

¥
cS

0 9 at

Wy

as

(Cannabis sativa).

38-B. Hemp

Fic.

mn

S

asSrSs ass = =

Witchell| s

Distribution of Hemp.

Fic, 38-C.

72 WEED FLORA OF IOWA

Distribution.—Waste places, New Brunswick south to North
Carolina and west to Minnesota, Kansas, and Rocky mountains.
Widely distributed through cultivation but often becoming a
troublesome weed. In many parts of Iowa; reported from Story,
Dubuque, Clinton, Polk, Boone, Allamakee, Winneshiek, Marshall,
Grundy, Plymouth, Pottawattamie and other counties.

Extermination.—Kasily killed by cultivation. Practice rotation
of crops.

Pellitory (Parietaria pennsylvanica Muhl.).

Description.—A low, annual, simple, or sparingly branched mi-
nutely downy plant; oblong-lanceolate, thin leaves with opaque dots;
flowers monoeciously polygamous shorter than involucre; glomerate
except in the lower axils; stigma sessile.

Fic. 39. Pellitory (Parietaria pennsylvanica). Common in shady places near
buildings.
(Photographed by Hart.)

DESCRIPTIVE MANUAL

73
SE aa Zo Naa
ee I,
' Seay eke]
A. NBRES
\ [ee ae : an oS
<= ee a Wee
onl ae N j
yey ee
ie
EL
Fic. 39-A. Distribution of Pellitory.
Distribution.—Massachusetts to Minnesota and southward. Com-

mon in Jowa in shady places, Jawns and woods. |

Fic. 39-B. Pellitory (Parietaria pennsylvanica.)

74 | WEED FLORA OF IOWA

Extermination.—This weed is usually exterminated by cultiva-
tion and may be destroyed by the application of iron sulphate at
the rate of 100 pounds to a barrel of water.

POLYGONACEAE, SMARTWEED FAMILY.

This family contains the pie plant, canaigre, prince’s feather,
and buckwheat.

Curled Dock, Yellow Dock (Rumez crispus L.).

Description.—A smooth perennial from 3-4 ft. high; leaves with
strongly wavy and curled margins, lanceolate and acute, lower leaves
with bases somewhat truncate or inclined to be heart-shaped ; flow-
ers collected in dense whorls, extended or prolonged into racemes,
entirely leafless above, but below with small leaves; 6 sepals, the 3
outer, herbaceous, leaflike, the 3 inner, larger and somewhat curled,

Fic. 40. Sour Dock, Curled Dock or Yellow Dock (Rumex crispus). Common
in low grounds, clover meadows, fields, etc.
(Photographed by Colburn.)

DESCRIPTIVE MANUAL : 75

Fic. 40-A. Distribution of ‘Curled Dock.

and after flowering forming the valves of the fruit, which surround
the 3-angled fruit, each valve bearing a grain. The R. altissomus
Wood. occurs in low ground, and is from 2-6 ft. high, with leaves
oblong, lanceolate, acute, pale, thickish, but without curled margins
as in R. crispus L., and longer; racemes long, spikelike, panicled,
nearly leafless; has a conspicuous grain.

Distribution.—It is native to Europe where it has long been known
as a troublesome weed ; common throughout eastern North America,
Pacific coast, and Rocky mountains; abundant in Iowa in clover
meadows, along roadsides and in pastures.

Chemical Composition.—The following analysis has been re-
ported.*

= s Nitrogen free Crude
Water | Protein | Fat eee) Fiber | Ash
81.6 | 21.7 | 3.9) | 39.4 | 11.4 | 9.3

‘Eatermination.—One of the most efficient means of destroying
this weed is to root it out by the hand and this is done very readily
in the spring when the soil is wet by taking hold of the plant just at
the surface of the ground, giving the root a slight twist and at the
same time an upward pull, when it will readily come from the soil.
Where it is common, however, it is sometimes plowed or a spud is
usec. This method is not, however, so effective as the pulling
method.

*Storer and Anderson.

76 WEED FLORA OF IOWA

Fic. 41. Curled Dock (Rumezx crispus). Roadsides, meadows, clover fields, ete.
(Photographed by Charlotte M. King.)

Clark and Fletcher suggest the following treatment: ‘‘Sow clean
seed. The prevalence of dock in meadows is due to sowing con-
taminated grass and clover seeds. Land worked under a short rota-
tion of crops is never badly infested with docks. When the soil is
soft after continued rain, they can be pulled from meadows and
pastures. Pull or cut and destroy all seed-bearing plants before
harvesting a clover seed crop. A handful of salt placed on the
crown of docks, after cutting in dry hot weather, will extract the
moisture and destroy the root; this is a remedy sometimes used in
lawns and pastures when the soil is too hard and dry to permit
pulling them.”’

Smooth Dock (Rwmezx altissimus Wood.).

Description.—A tall, smooth, perennial; leaves pale, ovate, or
oblong-lanceolate, thickish ; flowers in paniculate spikelike racemes,
in crowded whorls, nodding pedicels, shorter than the fruiting calyx;
valves broadly ovate or obscurely heart-shaped, one with a conspicu-
ous pale grain; achene triangular, pale.

Distribution —Common in the northern states and abundant in
low grounds and highways, also in pastures throughout Iowa.

DESCRIPTIVE MANUAL 77

Fic. 42. Smooth or Peach-leaved Dock (Rumexz altissimus). Low meadows,
roadsides and pastures.
(Photographed by Colburn.)

Fic. 42-A. Distribution of Smooth Dock.

78 WEED FLORA OF IOWA

Fic. 43. Smooth or Peach-leaved Dock (Rumex altissimus), Dandelion (Taraxa-
cum officinale), and other weeds. This is where the seed comes from to
spread weeds.

; (Photographed by Charlotte M. King.)

Extermination.—This weed has running roots and cannot be de-
stroyed in the same way as sour dock. The roots are, however, shal-
low, and can be destroyed by giving cultivation exposing the roots
to the sun.

Bitter Dock (Rumex obtustfolius L.).

Description.—A perennial herb, with roughish stem; leaves some-
what wavy, the lowest ovate heart-shaped, obtuse, the upper oblong-
lanceolate, acute; flowers inconspicuous, greenish on jointed pedi-
cels; valves of the fruit conspicuous, toothed at the base.

Distribution.—Naturalized from Europe; eastern Canada to Wis-
consin, Minnesota and south to Texas and Florida. It is found in
waste places, sparingly introduced into Iowa with clover seed.

Extermination.—The yellow spindle-shaped root is easily pulled
by giving the plant a slight twist, especially when the ground is
moist. Clover seed containing this weed should not be sown.

DESCRIPTIVE MANUAL 79

Fie. 44. Bitter Dock, Red Veined Dock (Rumex obtusifolius). Common in some
clover meadows in southern Iowa.
(Photographed by Colburn.)

Fic. 44-A. Distribution of Bitter Dock.

80 WEED FLORA OF IOWA

Sheep Sorrel (Ruwmez acetosella L.).

Description.—A low smooth annual or perennial, usually the lat-
ter, growing from 6-12 in. high, producing an erect stem, with hori-
zontal, creeping, woody root-stocks or rhizome; petioled, narrowly-
hastate, narrow, lanceolate leaves, the upper linear; flowers on
jointed pedicels, dioecious, small, in a terminal naked panicle; small
green calyx; exserted stamens; the valves not enlarging in fruit.

Distribution.—Sheep sorrel has long been known as a troublesome
weed in Europe, and in the northern states; perhaps indigenous to
the United States; at least now common across the continent in the
north. It is common everywhere in Iowa, more particularly in sandy
or gravelly soils.

Extermination.—The plant succumbs quite readily to cultivation,
and where the fields are thoroughly cultivated with hoed crops, it
is seldom troublesome more than one season: In fact the vast ma-
jority of plants may be killed by cultivating the soil once or twice.
The roots though produced abundantly seem to be unable to stand
drying. The soil on which it occurs should receive a heavy coat of
manure. This seems to be approved by Dr. Halsted who says:
‘“This pest can be sulnelne by keeping the infested land Hees the
plow for a short time.’

Clark and Fletcher say in regard to this weed: ‘‘Sheep sorrel
is said to be an index of soil characters. It seems to thrive best on
sandy or gravelly soils deficient of hme. An application of lime to
slightly acid soils produces a more vigorous growth of cultivated
erops and curtails the opportunities of the sorrel to grow and spread.
Old meadows and pastures that are overrun with it and that can-
not well be brought under cultivation may be pastured with sheep
for two or three years to prevent it from seeding freely.

A three-year rotation of crops with good cultivation, including
shallow plowing directly after hay crop and frequent cultivation
until autumn to prepare for hoed crops, will keep sheep sorrel well
under control even on lands that seem to be specially Smee) to its
growth.’’

Wallace’s Farmer suggests the following: ‘‘To control this weed
in the meadows we would suggest applying manure and thickening
up the grass stand. Putting the land into a cultivated crop destroys
this weed.’’

Fic. 45.

DESCRIPTIVE MANUAL

SHEEP SORREL

{Rumex Aceroselia 4)

Sheep Sorrel or Horse Sorrel (Rwmex acetosella).
and gravelly soil.
(After Clark and Fletcher.)

81

Common in sandy

82 WEED FLORA OF IOWA

Fic. 45-A. Distribution of Sheep Sorrel.

Chemical Composition—The ash of this weed is reported by Wein-’
hold as follows:

Phosphorie acid | Potash | Sodium | Lime | Magnesia

927 | ONT | 1.3 | 14.0 | 9.4
|

Erect Knotweed (Polygonum erectum L.)..

Description.—An annual, glabrous, stout, erect, or ascending yel-
lowish green herb, 1-2 ft. high, with elliptical leaves; flowers yellow-
ish and inconspicuous, 1-2 in an axil; stamens 5-6; achene dull,
included.

Distribution.—Widely distributed from the northeast to Mani-.
toba, Wisconsin, Minnesota to Arkansas, and eastward. Common
in Iowa especially eastward, and in Story, Boone, Marshall, Polk,
Allamakee, Clinton and Dubuque counties. ,

Extermination.—Easily exterminated by cultivation.

DESCRIPTIVE MANUAL

state.

Pic. 46. Erect Knotweed (Polygonum: erectuwm). Common in many parts of the
(Photographed by Hart.)

Fic. 46-A. Distribution of Brect Knotweed.

83

84 WEED FLORA OF IOWA

Dooryard Knotweed (Polygonum aviculare L.).

Description.—A scattered or somewhat ascending, bluish grey an-
nual; leaves acute or acutish; flowers greenish with pinkish mar-
gins; achenes triangular, dull and minutely granular-striate.

Fic. 47. Dooryard Knotweed (Polygonum aviculare). Common in dooryards.
(Photographed by Hart.)

ig. 47-A. Distribution of Dooryard Knotweed.

DESCRIPTIVE MANUAL. ° 85

Distribution.—Native in the northern hemisphere, Asia and North
America, common everywhere in Jowa in gardens and waste places.
Usually affected by a white mildew.

Extermination.—This annual weed can be destroyed only by giv-
ing the soil on which it occurs cultivation. It frequents dry and
more or less beaten soil. Where it is abundant in lawns the soil
should be stirred and sown to white clover.

Bushy Knotweed (Polygonum ramosissimum Mx.).

Description.—An erect or ascending, green or yellowish green
smooth herb 2-4 ft. high; leaves linear or lanceolate, tapering into a
petiole; flowers inconspicuous, greenish; stamens 3-6; style short;
achene 3-angled.

Fic. 48. Bushy or Hrect Knotweed (Polygonum ramosissinum). Common in
fields.
(Photographed by Hart.)

&6 WEED FLORA OF IOWA

Fic. 48-A. Distribution of Bushy Knotweed. .

Distribution —From Manitoba to Texas, also in Pennsylvania;
frequent in fields in many parts of Iowa, in Story, Boone, Worth,
and Cerro Gordo counties.

Extermination.—Easily exterminated by cultivation.

Pink Smartweed (Polygonum lapathifolium L.).

Description.—Pink smartweed isa native, glabrous, erect annual,
with stem swollen at the nodes; lanceolate, acuminate leaves with
short ciliate petioles; racemes panicled, nodding, with many flow-
ers; calyx white or pink, small 5-parted; 6 stamens, style included ;
achene lenticular.

Distribution.—This weed occurs from New England to Nebraska
and Louisiana. Native to Europe, and common in eastern North
America ; everywhere in Iowa, particularly in moist situations.

Extermination.—Easily exterminated, after drainage of slough,
by cultivation.

DESCRIPTIVE MANUAL | 87

Fic. 49. Pink or Nodding Smartweed (Polygonum lapathifolium). . Common
in corn fields.
(Photographed by Colburn.)

Fig. 49-A. Distribution of Pink Smartweed.

88 WEED FLORA OF IOWA

Marsh Smartweed (Polygonwm muhlenbergu (Meisn.) Wats.).

Description—A somewhat pubescent or scabrous perennial with
large black roots, decumbent or erect; leaves lanceolate to ovate,
narrowly acuminate; flowers in rather long hispid spikes; sepals 5,

Fic. 50. Tanweed, Marsh or Muhlenberg’s Smartweed, Devil’s Shoe-string or
Shoe-string (Polygonum muhlenbergii) ; a, plant hairs. Low meadows and
fields.

(Photographed by Colburn. Drawing by Charlotte M. King.)

cee [ne aia ae

Fic. 50-A. Distribution of Marsh Smartweed.

DESCRIPTIVE MANUAL | 89

bright rose color; stamens 5, styles 2-cleft, exerted. Frequently
only sterile plants, or flowering rather late in the season; trichomes
multicellular, at base with thick outer epidermal walls.

Distribution.Common from Canada to Florida and west, found
in all parts of Iowa; an exceedingly variable plant; sometimes found
in very moist situations, and in stagnant water, or in somewhat
higher but poorly drained situations. The black, thickish roots are
quite characteristic of the plant.

Extermination.—Marsh smartweed or tanweed, as it is sometimes
called, is a persistent perennial and since the weed grows in wet
places it is particularly difficult to destroy. The best method of

Fic. 51. Tanweed, Marsh Smartweed (Polygonum muhlenbergii).
(Photographed by W. Newell.)

90 WEED FLORA OF IOWA

treating it is by thorough cultivation, exposing all the root-stocks
to the sun, then removing the young plants as rapidly as they make
their appearance.

Wallace’s Farmer suggests the following treatment: ‘‘It grows
less vigorously on well drained land, hence the first step in eradica-
tion is to drain the field thoroughly. The summer fallow is perhaps
the best course of treatment. Plow the infested patch early and
keep the disk and plow working on it regularly all summer long.
All the roots that can be located should be pulled up and burned
after drying out. A heavy pitchfork and plenty of muscle will soon
fill a wagon box with the long, tough, yellow roots. A heavy seed-
ing of sorghum helps to weaken the stand, but we have seen patches
as vigorous as ever a year after two succeeding crops of sorghum
had been grown in an effort to smother out the pest.”’

Smartweed (Polygonum pennsylvanicum L.).

Description.—An annual 1-2 ft. high, with lanceolate leaves;
branches below the flowers beset with numerous stalked glands;
flowers whitish or rose-colored; stamens 6-8, style 2-cleft; fruit an
achene, 134 lines long, flattened, brown, shining, part of the calyx
remaining attached to the base. |

. Distribution.—Pennsylvania smartweed is common from New
England southwestward and westward and in every part of Iowa,
coming up abundantly in corn fields, sometimes forming a mass of
rose-colored flowers; also growing up abundantly in grain fields
after harvest.

Extermination.—This smartweed is easily exterminated by cul-
tivction.

DESCRIPTIVE MANUAL . 91

Fie. 51-A. Pennsylvania Smartweed (Polygonum pennsylvanicum). Common in
corn fields.
(Photographed by Colburn.)

Hic. 51-B. Distribution of Pennsylvania Smartweed.

92 WEED FLORA OF IOWA

Fie. 51-C. Smartweed (Polygonum pennsylvanicum).
(Photographed by W. Newell.)

Water Pepper (Polygonum hydropiper L.).

Description.—Much like P. persicaria but more slender and often
decumbent ; flowers greenish on slender nodding spikes; achenes dull
in color and the whole plant more or less acrid.

Distribution—Water pepper is widely distributed in eastern
North America; naturalized from Europe or may be indigenous in
the northwest. Widely distributed in Iowa.

Extermination.—This weed is usually found in moist places and
is not very troublesome in cultivated fields except in low places.
Fields that are badly infested with it should be plowed and drained
and if possible some leguminous plants like alsike clover sown.

DESCRIPTIVE MANUAL 2 93

Fic. 52. Common Smartweed or Water Pepper (Polygonum hydropiper).
(Photographed by Colburn.)

Lady’s Thumb (Polygonum persicaria L.).

Description—A nodding, smooth, glabrous annual; sheaths
bristly ciliate; leaves lanceolate, marked with a conspicuous dark
or lunar spot; spikes short cylindric; peduncles smooth ; achene flat-
tened, smooth and shining.

Distribution —Lady’s thumb is native to Europe, common in east-
ern North America, Rocky mountains and on the Pacific coast.
Common everywhere in Iowa, particularly in waste places and gar-
dens, and growing up abundantly after grain has been harvested.

Extermination—This weed is easily destroyed by cultivation.
The main point, however, is that seed production must be prevented ;
hence it would be well to cut off the plants after they have started
to produce flowers; this will effectually prevent seed production.

94 WEED FLORA OF IOWA

Plate It

PALE PERSICARIA

POIUSAHUM FAP AMI OnUn £4.

Fic. 53. Lady’s Thumb (Polygonum perstcaria). Common in gardens, fields
and along roadsides. )
(After Clark and Fletcher.)

DESCRIPTIVE MANUAL 95

Fic. 53-A. WListribution of Lady’s Thumb.

Water Pepper or Smartweed (P. hydropiperoides Mx.).
Description —A perennial not acrid; leaves narrowly lanceolate
or oblong; small flesh-colored flowers in erect slender spikes ; smooth
achenes sharply triangular.

Fig. 54. Water Pepper (Polygonum hydropiperoides). Common in low places,
fields, etc.
(Photographed by Colburn.)

96 WEED FLORA OF IOWA

Fic. 54-A. Distribution of Water Pepper.

Distribution.—Water pepper is distributed in swamps from east-
ern Canada southwest to Mexico; it is also distributed across the
northern states to California; common in low wet places in many
parts of Iowa.

Fic. 54-B. Water Smartweed (Polygonum acre).

DESCRIPTIVE MANUAL 97

Wie. 54-C. Distribution of Water Smartweed.

Extermination—Since this perennial weed is most abundant in
sloughs, drainage must be resorted to before an effective means of
extermination can be used. After this it will give little trouble in
cultivation.

The Water Smartweed (Polygonum acre H B K) is a nearly
smooth perennial with stems rooting at the decumbent base; erect,
dense spikes of whitish or flesh-colored flowers. It is common in
low grounds.

Black Bindweed or Wild Buckwheat (Polygonum convolvulus L.).

Description—An annual, twining, with smooth joints; leaves
halberd or heart-shaped; flowers in corymbose racemes; achene dull
black, triangular and minutely roughened.

Distribution—This weed is widely scattered with grain seed,
especially with wheat and oats. It is often most troublesome in
small grain fields. In Iowa, however, it occurs in gardens and along
roadsides.

Extermination.—It is not difficult to destroy the weed by giving
clean cultivation, since it succumbs easily to such treatment. Sow
only clean seed.

Clark and Fletcher recommend as follows: ‘‘Sow clean seed
grain. The seeds retain their vitality for a relatively short period,
probably not longer than three years, except in the drier soils of the
western plains. The suppression of this pest is therefore largely
dependent on the prevention of a continued supply of fresh seeds to
the soil. This weed gives little trouble on land under a short rota-

tion of crops, including hay, for two years.
7

98 WEED FLORA OF IOWA

Fie. 55. Bindweed or Wild Buckwheat (Polygonum convolvulus). Common in
' grain fields and waste places.-
(After Clark and Fletcher.)

DESCRIPTIVE MANUAL : 99

Fig. 55-A. Distribution of Black Bindweed.

_The seeds of wild buckwheat do not germinate in the spring until
the soil is quite warm. Most of the early plants can be destroyed
in the grain crops by an application of the harrow when the grain
is about three inches high. The young plants soon root firmly and
the harrowing, to be effective, must be done just as they emerge
from the ground.’’

CHENOPODIACEAEH, GOOSEFOOT FAMILY.

This family contains the spinach, sugar beet, beet and salt bushes.

Winged Pigweed (Cycloloma atriplicifolium (Spreng.) Coult.).

Description—An annual with alternate sinuate-toothed petioled
leaves; small inconspicuous flowers in open panicles; winged seeds ;
herb diffusely spreading or often spherical in form similar to the
Russian thistle or Jowa tumbleweed.

Distribution.—Native from Manitoba, Minnesota, to Illinois, Ark-
ansas and the Rocky mountains. In Iowa it is found along Missis-
sippi river in Dubuque and Muscatine counties, in Linn county,
and along Missouri river.

Extermination—This weed is easily exterminated by cultivation.
In Iowa has probably been spread with western grass seed and in
stock ears. .

100 WEED FLORA OF IOWA

Fic. 56. Western Tumbleweed or Winged Pigweed (Cycloloma atriplicifolium)
Sandy soil, Muscatine Island, etc.
(Photographed by Colburn.)

Fic. 56-A. Distribution of Winged Pigweed.

DESCRIPTIVE MANUAL : 101

A

Fic. 57. Winged Pigweed (Cycloloma atriplicifolium). Seed and cross section of
ovary.
(After W. J. Beal, Mich. Agr. Exp. Sta.)

Mexican Fireweed (Kochia scoparia Schrad.).

Description—An annual, erect, puberulent or glabrate herb;
leaves lanceolate to linear, ciliate acuminate; flowers sessile in the
axils of the upper leaves, forming short dense-bracted spikes; fruit-
ing calyx segments each with a short triangular horizontal wing.

WEED FLORA OF IOWA

(Drawn by F. C. Collins.)

DESCRIPTIVE MANUAL 103

Fic. 58-A. Distribution of Mexican Fireweed.

Distribution—In waste places commonly cultivated and now a
frequent escape in lowa. Common in many of the northern states,
Rocky mountains and the Pacific coast. From eastern Europe and
western Asia.

Extermination.—This weed is easily exterminated by cultivation.

Mexican Tea (Chenopodium ambrosioides L.).

Description.—A smoothish annual, or slightly pubescent; strong
scented ; leaves oblong or lanceolate, entire or cut-pinnatifid, nearly
sessile; spikes densely flowered, leafy; flowers in small, dense, axil-
lary spikes; calyx 3-parted enclosing the fruit. The wormseed
(C. anthelmanticum) is an annual or sometimes a perennial; leaves
more strongly toothed; the flowers usually in bractless panicled
spikes.

Distribution —Mexican tea is found southward, occurring, how-
ever, from Maine to California. The wormseed has nearly the same
distribution occuring northward to Minnesota and Wisconsin.
Neither of these weeds is common in Lowa.

Extermination.—In Iowa both of these weeds are easily extermin-
ated by cultivation. Do not permit any of their seeds to mature.

104 WEED FLORA OF IOWA

Fic. 59. Mexican Tea (Chenopodium ambrosioides). In southern Iowa; streets
and fields.
(Photographed by Colburn.)

Fic. 59-A. Distribution of Mexican Tea.

DESCRIPTIVE MANUAL | 105

Fic. 59-B. Plant hair or trichome of (Chenopodium botrys). a, from stem;
b, glandular trichomes from calyx.
(Drawn by Charlotte M. King.)

Maple-leaved Goosefoot (Chenopodium hybridum L.).

Description.—A bright green annual from 2-4 ft. high; widely
branching, with an unpleasant odor like stramonium; leaves thin,
triangular, heart-shaped sinuate-toothed; flowers inconspicuous, in
loose, racemose panicles; calyx covering the fruit; seed firmly at-
tached to the pericarp.

Distribution.—Frequently found in woods and waste places; ex-
tending from Kansas to Manitoba, Wisconsin and Minnesota and
southward ; common in Story, Boone, Marshall, Clinton, Polk, Wood-
bury, Pottawattamie, Dubuque, Allamakee and Cerro Gordo coun-
ties.

Extermination.—This annual weed can be killed by giving clean
cultivation. Sometimes distributed with clover seed, but less fre-
' quently than the other species. Sow clean clover seed.

106 WEED FLORA OF IOWA

Fic. 60. Maple-leaved Goosefoot (Chenopodiwin hybridum). Frequent in woods
and waste places.
(After Mich. Agr. Exp. Sta.)

DESCRIPTIVE MANUAL 107

Fic. 60-A. Distribution of Maple-leaved Goosefoot.

Lamb’s Quarters, Pigweed. (Chenopodium album L.).

Description—An erect annual from 1-4 ft. high; young plants
generally mealy, older plants smooth ; leaves rhombic-ovate to lance-
olate or the upper sometimes linear, acute, lower commonly toothed ;
flowers produced in clustered, dense-spiked panicles; calyx 5-parted,
nearly covering the seed; seeds surrounded by a loose pericarp form-
ing an utricle.

Distribution.—Native to Europe; widely naturalized in eastern
North America and the Rocky mountains; occurs in Utah and on
the Pacific coast ; found everywhere in Iowa in cultivated fields and
in gardens as well as along highways.

Extermination—Plants of this species produce an enormous
number of seeds. The young plants are easily destroyed by cutting
off below the ground. Covering the young plants is not effective
unless the entire plant is covered. Older plants may be destroyed
by pulling them up. The weed on account of the shade it produces
destroys other vegetation underneath it.

Chemical Composition.—According to a report of the Bussey In-
stitution, the chemical composition is as follows :*
*Bull. Bussey Inst., 1877: Jenkins and Winton; Office Exp. Sta., Bull. 11.

108 WEED FLORA OF IOWA

Plate 2

LAMBS QUARTERS orn PIGWEED

(Chenopodium albums)

Fic. 61. Lamb’s Quarters (Chenopodium album). Common in gardens and fields.
(After Clark and Fletcher.)

DESCRIPTIVE MANUAL ~ ; 109

Fic. 61-A. Distribution of Lamb’s Quarters.

FRESH OR DRY AIR MATERIAL.

Nitrogen free

Water | Ash | Protein | Fiber eceen Fat
80.80 | 3.02 | 3.94 2.55 | 8.93 | 0.76
WATER FREE SUBSTANCE.

| 15.7 | 20.5 | 13.3 | 46.5 | 4.0

Orach (Atriplex patula L. var. hastata (li.) Gray.).

Description.—A pale green or purplish, slightly scurfy, annual,
2-3 ft. high; leaves slender-petioled narrowly lanceolate-hastate, en-
tire or somewhat sinuate-dentate ; flowers inconspicuous, interrupted,
slender-panicled spikes.

Distribution—Found from eastern Canada northeast to Wiscon-
sin and Iowa. In Iowa somewhat widely scattered.

Extermination—KHasily exterminated by cultivation. Sheep are
fond of it and may be utilized to destroy the weed.

110

Fic. 62.

WEED FLORA OF IOWA

Orach (Atriplex patula var. hastata). Streets, gardens, roadsides.
(Photographed by Colburn.)

Fig. 62-A. Distribution of Orach.

\

DESCRIPTIVE MANUAL N ialab
d \

Russian Thistle (Salsola Kali L. var. tenuifolia G. F. W. Mey).

Description.—An herbaceous, smooth or slightly pubescent an-
nual, diffusely branched from the base, from 114-3 ft. high, spherical
in the mature form; leaves fleshy, alternate, succulent, linear, sub-
terete, 1-2 in. long, pointed in the older specimens, upper leaves in
the mature plant persistent, each subtending 2 leaf-like bracts and
a flower ; stem and branches red; apetalous flowers solitary and ses-
sile; calyx consisting of 5 persistent lobes, enclosing the dry fruit
which is usually rose-colored, about 1-12 in. long; 5 stamens nearly
as long as the calyx; pistils with 2 slender styles producing a single
obconical depressed seed, dull gray or green, without albumen; em-
bryo spirally coiled; on germination cotyledons are subterete. The
plant flowers in July or August, the seeds maturing in August.

Distribution—Russian thistle is native of Russia and western
Asia. Since its introduction into the Dakotas it has been widely
scattered in the northern states and is common from Minnesota to
the Pacific northwest and in the Rocky mountains from Montana to
New Mexico. It is widely scattered in Iowa but abundant only dur-
ing dry years, along the right of way of railways, and in the vicinity
of stockyards.

Extermination —The Russian thistle as said before, is an annual,
hence it would seem an easy matter to destroy it; and as a matter of
fact, when taken in time, it is not a difficult weed to remove. Its nox-
iousness comes largely from the fact that the plant is so productive.
If a Russian thistle is once cut off at the surface of the ground it
never grows again; hence in cultivated fields it is not likely to prove
a great pest. The question is, however, a very different one in pas-
tures, meadows and roadsides; here the weeds cannot be removed
by cultivation and many of the plants mature their seeds unobserved.
The removal of the weeds along the roadsides is important, because
it is largely from this source that our fields become infested. The
removal of such weeds can be best accomplished by running over the
patch with ia mower.

Fletcher and Clark recommend as follows: ‘‘Hand-pull wherever
practicable. Harrowing growing crops is an effective remedy ; it is
easily killed by this method when young. The harrow should be ap-
plied just before the grain emerges from the ground and again when
the crop is three inches high.’’

112 WEED FLORA OF IOWA

Fic. 63. Russian Thistle (Salsola kali var. tenuifolia). Common in western
Iowa. Fleshy herb becoming spiny.
(Photographed by Gardner.)

ees Yb YS SN
vara att BRP NS Sar
IA eae
RUUL hse, ih
wd [OT Sek
ashy

isin

| SES
1) aaa
PEC OECE

Fic. 63-A. Distribution of Russian Thistle.

DESCRIPTIVE MANUAL ~ 113

Wallace’s Farmer suggests the following treatment: ‘‘Russian
thistle is easily controlled by cutting it off just below the surface of
the ground before it seeds in August. It has not proved a dangerous
weed east of Mississippi river.’’

CHEMICAL COMPOSITION.

Original Dry

Sample Matter
RWWiaihentiet = seen eae sa Se Oe Ss ae eats es BE Oot Poe an Ole neasece
raya LOVER GG CT ee ee ee ae ee es ADT4S en were ete
100 parts contain: ‘

VV Su IG Tome ea oe ae a a ee Se ee ee SESH eT aoe Paleetc. ele
Om Gas nes aa ee Se a ee ea ee 3.41 22.01
Ht hereextractie(Chide) fat) 2222 2a. eee ee ee ce 84 2.20
Nitrogen free extract (soluble carbohydrates)_________-____ 6.10 39.39
(CTU GER Tir ee ae ee 2.78 17.94
Crude protein (total nitrogen x 6.25)_-----._---____._______.. 2.86 18.46
True albuminoids (albuminoid N x 6.25)_-----------___-_-_- (2.22) (14.35)

100.00 100.00

AMARANTHACEAE, PIGWEED FAMILY.

This family contains few economic plants. Some, like the cock’s-
comb, are grown for ornamental purposes.

Pigweed, Redroot (Amaranthus retroflexus L.).

Description—A roughish, more or less pubescent annual; 3-5 ft.
tall; leaves ovate or rhombic-ovate, undulate ; long-margined petiole,
entire; flowers in thick spikes crowded in a stiff or bunchy, spiky
panicle; bracts subulate, longer than the mucronate or obtusely-
tipped sepals.

Distribution.—A weed throughout North America, especially east-
ward ; abundant in every county in the state.

Extermination—Frequently distributed with clover seed; sow
clean clover seed in a clean field. Easily exterminated by cultiva-
tion.

Fletcher and Clark recommend as follows: ‘‘When embedded in
the soil, the seeds retain their vitality for several years, though prob-
ably not more than five in a moist soil, and produce seedling plants
only when brought by cultivation within about two inches of the
surface.’’

8

114 WEED FLORA OF IOWA

Fic. 64. Pigweed, Redroot (Amaranthus retroflexus). Common in gardens,
roadsides and fields.
(After Clark and Fletcher.)

DESCRIPTIVE MANUAL 115

: Ce an es
Ve as

Fig. 64A Figure 64B

Fic. 64-A. Trichomes or plant hairs from stem of pigweed.
(Drawing by Charlotte M. King.)

Fic. 64-B. Distribution of Pigweed.

Chemical composition According to the University of Minnesota
the composition is as follows :*

V

5 Nitrogen free
Dry Matter Crude Protein Ether Extract cata and Ash
ber
97 .00 | 26.54 | 1.36 | 62.86 | 9.24

Tumbleweed (Amaranthus graecizans L.).

Description—A smooth, pale green much-branched annual; at
maturity a spherical mass, which separates easily from the root;
leaves oblong-spatulate or ovate; small flowers greenish, inconspicu-
ous, polygamous, several together in small axillary clusters, small
and pointed.

Distribution—Common in North America especially from Ohio
westward. In waste grounds. The detached leafless plants may
be seen rolling over fields.

Extermination.—Hasily exterminated by cultivation.

*Bull. Minn. Agr. Exp. Sta.. 11, by Harry Snyder.

116 WEED FLORA OF IOWA

Fic. 65. Iowa Tumbleweed or Tumbling Pigweed (Amaranthus graecizans).
Common in corn fields. Plant grows in circular form, separates from the
root in the autumn and rolls over and over, scattering the seeds.

(Photographed by Hart.)

Fie. 65-A. Distribution of Tumbleweed.

DESCRIPTIVE MANUAL © 117

Prostrate Pigweed (Amaranthus blitoides Wats.).
Description.—A diffusely branched, prostrate herb, spreading on
the ground, often in mats 4 or 5 ft. long; leaves obovate or spatu-
late; flowers inconspicuous, greenish, in short axillary clusters.

Fic. 66. Prostrate Pigweed (Amaranthus blitoides). Common along roadsides,
streets, fields, and in waste places.
(Photographed by Hart.)

i Cs ae

Serekeh aces

See
: areereicaa' xt

Fic. 66-A. Distribution of Prostrate Pigweed.

118 WEED FLORA OF IOWA

Distribution—Common in every county in the state of Iowa and
east to northeast; indigenous to the Rocky mountains.

Extermination.—Easily exterminated by cultivation.

Water Hemp (Acnida tuberculata Moq.).

Description.—A tall, erect annual; leaves lanceolate to rhombic-
ovate, acute, or acutish; flowers dioecious; pistillate flowers small,
green, clustered in naked or leafy terminal and axillary spikes;
staminate flowers pale; dehiscent pericarp thin.

The Acnida tamariscina (Nutt.) Wood, of similar habit. Has
cireumscissille fruit, otherwise like the A. twherculata.

Distribution—Common along water courses, prairies and marshes
from northeast to Minnesota and Dakota. Found in Iowa in Story,
Boone, Polk, Pottawattamie, Woodbury, Emmet, Cerro Gordo, Clin-
ton, Linn, Marshall and Allamakee counties.

Fic. 67. Water Hemp (Acnida tuberculata). Common plant with yellowish
aspect. In old lake beds and prairies.
(Photographed by Colburn.)

DESCRIPTIVE MANUAL ~ 1518,

Fie. 67-A. TListribution of Water Hemp.

Extermination.—KHasily exterminated by cultivation; not mfre-
quent in clover seed, and not long present in wall cultivated fields
especially when they are well drained.

NYCTAGINACEAE, FOUR-O’CLOCK FAMILY.

This family contains the well known cultivated four-o’clock.

Four-o’clock, Umbrella Plant (Oxybaphus nyctagineus (Mx.)
Sweet. )

Description.—A nearly smooth, deep-rooted perennial 2-4 ft. high ;
forking leaves, broadly ovate, cordate, or lanceolate, opposite, round-
ed or truncate at base; petioled involucre; flowers persistent ; fruit
obovoid, pubescent; calyx bell-shaped, rose or purple; stamens gen-
erally 3. |

Distribution.—F rom Manitoba to Louisiana, introduced eastward ;
common in cultivated fields, on railway embankments and in waste
places.

Extermination.—This weed propagates both by its seed and root;
however, it is not difficult to destroy when the roots are cut off
during dry weather.

Wallace’s Farmer suggests the following treatment: ‘‘The
wild four-o’clock, although not yet very common in the corn
belt, has possibilities of becoming a bad weed. It is a perennial,
with a big, fleshy root and spreads freely from the seed. It spreads
very little from the root. This weed may be exterminated in time
by cutting it off close to the ground every year just before it seeds.”’

120 WEED FLORA OF IOWA

Fic. 68. Wild Four-o’clock (Oxybaphus nyctagineus). Common in fields, along
roadsides and on railway embankments. Plants have a long, stout root.
(Photographed by Colburn.)

Fic. 68-A. Distribution of Wild Four-o’clock.

CARYOPHYLLACEAH, PINK FAMILY.. —

This family contains the well known carnation, spurrey and gar-
den pink.

.

DESCRIPTIVE MANUAL . 121

Chickweed (Stellaria media (L.) Cyrill.).
Description.—An annual, or winter annual, whose spreading
stems are marked with one or more pubescent lines; leaves ovate

COMMON CHICKWEED

med

iStetlaria

(After Clark and Fletcher.)
Fic. 69. Chickweed (Stellaria media). Gardens, lawns, dooryards.

122 WEED FLORA OF IOWA

Fic. 69-A. Distribution of Chickweed.

or oblong, from 14 to 21% in. long, lower leaves on hairy petioles,
sepals 4 or 5, greenish; petals 4 or 5; shorter than the calyx and
2-parted; stamens 3-10; styles 3. Pod ovoid.

Distribution.—Chickweed is widely distributed in the northern
states to the Pacific coast; naturalized from Europe; common 1m
many places in lawns and in shady places, not especially trouble-
some except on the lawn, where often it runs out blue grass.

Extermination.—This weed is easily exterminated by cultivation.
Since the lawn, however, cannot be cultivated the best and most ef-
fective means of exterminating the weed is to spray with iron sul-
phate at the rate of 100 pounds to a barrel of water. Spray as soon
as the plants make their appearance and repeat 2 to 5 times during
the season.

Nodding Chickweed (Cerastium nutans Raf.).

Description.—A clammy, pubescent, much-branched annual with
slender, erect stems 6-20 in. high; leaves oblong, lanceolate, acute,
the lowest spatulate; flowers numerous in open loose cymes; pods
nodding on the stalks, curved upward, larger than the calyx. The
larger mouse-ear chickweed (Cerastiwm viscosum) is a perennial
with obovate, clammy, hairy stem; leaves varying from oblong to
lanceolate ; flowers clustered at first; sepals rather obtuse, small.

The common mouse-ear or chickweed (C. vulgatum) is a peren-
nial with clammy pubescence.

-

Distribution.—From New England to Minnesota, especially south-
ward in southern Iowa and Missouri.

DESCRIPTIVE MANUAL |. 123

Fic. 70. Nodding Chickweed (Cerastium nutans). Common in fields, waste
places and streets, southern Iowa.
(Photographed by Colburn.)

Extermination—Thig annual is easily exterminated by cultiva-
tion. .When it occurs in places that cannot be cultivated, like pas-
tures and lawns, iron sulphate at the rate of 100 pounds to a barrel
of water may be used.

124 WEED FLORA OF IOWA

Fic. 70-A. Mouse-ear or Chickweed (Cerastium vulgatum). Common in pas-
tures.
(Photographed by Colburn.)

Fic. 70-B. Distribution of Larger Mouse-ear or Chickweed (Cerastiwm vis-
cosum).

DESCRIPTIVE MANUAL. 125

Corn Cockle (Agrostemma githago i.)

Description.—A hairy, annual weed, clothed with long, soft hairs;
leaves linear-lanceolate, acute or long-acuminate ; flowers purple and

Fic. 71. Corn Cockle (Agrostemma githago). In grain fields.
(After Clark and Fletcher.)

126 WEED FLORA OF IOWA

Fic. 71-A. Distribution of Corn Cockle.

long peduncled; calyx lobes long, linear, surpassing the purplish
_ red petals; seeds large, roughened and black.

Distribution.—A weed long known as troublesome in European
grain fields, and widely scattered throughout the grain growing sec-
tion of North America. It is most abundant in Jowa in the wheat-
growing section but occasionally is found in other places around
orain elevators.

Extermination.—This weed is an annual and in order that it may
be checked in its spread, use only clean seed. The seed should be
put in clean soil.

Fletcher and Clark recommend as follows: ‘‘In the prairie pro-
vinces, harrowing the grain crop just before it emerges from the
gound and again when it is about three inches high keeps down this
weed. Where the land is infested with purple cockle, a thorough
summer fallow is the best method of getting rid of it.’’

White Campion (Zychnis alba Mill.).

Description —aA freely branching biennial, with a slightly plea-
sant odor; leaves ovate-oblong or ovate-lanceolate; flowers loosely
paniculate, white or pink, fragrant; capsule ovoid-conical, swelling
with the ripening of the pod; petals 2-cleft, crowned.

Distribution.—Introduced with clover seed from Europe, not,
however, as common in the east as Lychnis diovca.

DESCRIPTIVE MANUAL ; UPA

Fic. 72. White Cockle (Lychnis alba). In clover meadows.
(After Clark and Fletcher.)

128 WEED FLORA OF IOWA

Fic. 72-A. Distribution of White Cockle.

Extermination.—This weed can be exterminated by cutting off
the plants when in bloom or by cutting them off a few inches below
the surface of the ground. Since this weed is being spread with
European clover seed, care should be used to sow only clean clover
seed.

Catchfly (Silene dichotoma Ehrh.).

Description.—A tall, more or less hirsute, annual, somewhat viscid,
pubescent; leaves lanceolate or oblanceolate; flowers in branched
racemes, short-pediceled in the forks, or solitary at the nodes; calyx
5-ribbed, hirsute; petals white or pink, bifid.

Distribution —Introduced from Europe, spreading occasionally
in clover fields from the northeast to Iowa and Texas, also to the
Pacific coast.

Extermination —A remedy in this case is to sow only clean seed,
clean clover or alfalfa seed in clean soil in localities where the weed
occurs. Give thorough cultivation. Do not allow any of the plants
to go to seed.

DESCRIPTIVE MANUAL 129

Fic. 73. Catchfly (Silene dichotoma Hhrh.). In waste places.
(W. J. Beal, Mich. Agr. Exp. Sta.)

130 WEED FLORA OF IOWA

Fic. 73-A. Distribution of Catchfly.

Night-flowering Catchfly (Silene noctiflora L.).

Description —A viscid, pubescent annual from 2-3 ft. high; lower
leaves spatulate, upper lanceolate and pointed; flowers few, large,
peduneled, white, fragrant; calyx prominent veined; pod enlarged
in ripening of the fruit.

Distribution—In waste places in Europe, Canada to Manitoba
and southward, found in many counties in Iowa.

Extermination.—This weed is easily exterminated by cultivation.
It has been widely spread in recent years with clover seed, particu-
larly clover seed coming from the east and from Europe. Sow only
clean clover seed on clean soil.

Fletcher and Clark make the following suggestions for extermin-
ating the weed: ‘‘ Farmers who sow clover and grass seed free from
the seeds of catchfly will not long have trouble with it on lands
worked under a short rotation of crops. A rotation of crops ex-
clusive of alsike seed should be adopted for six or eight years. Grass

DESCRIPTIVE MANUAL 131

Fic. 74. Night-flowering Catchfly (Silene noctiflora). In clover meadows, gar-
dens, ete.
(After Clark and Fletcher.)

132 WEED FLORA OF IOWA

Fic. 74-A. Distribution of Night-flowering Catchfly.

or clover seed containing catchfly should be thoroughly cleaned in
mills equipped with screens specially designed to remove this im-
purity, and should not be used on land that may later be required ~
for the production of alsike seed.’’

Cow-herb (Saponaria vaccaria L.).

Description—A glabrous annual, from 1-2 ft. high with opposite
ovate-lanceolate leaves; flowers in corymbed cymes; calyx 5-angled,
enlarged and angled in fruit; petals pale red.

Distribution.—This weed has long been known as troublesome in
grain fields of Europe, and is common in North America. It is com-
mon in lowa only where wheat is grown.

Extermination.—Clean seed sown in clean soil is the only method
of exterminating the weed.

Clark and Fletcher suggest the following treatment: ‘‘Sow clean
seed. Prevention is the best and least expensive method of fighting
it. Itis a large showy plant and when not present in excessive num-
bers can easily be hand-pulled. The seed will not retain its vitality
‘long; when land is seeded to timothy or western grass and left for a
few years, the supply of vital seeds in the soil will be greatly re-
duced, if not entirely exhausted.’’

Fie. 75.

.
se
2

Cow-herb (Saponaria, vaccaria).
(Clark and Fletcher.)

In grain fields.

134 WEED FLORA OF IOWA

Fic. 75-A. Distribution of Cow-herb.

Bouncing Bet (Saponaria officinalis L.).

Description.—Perennial herbs with large flowers in cymose clus-
ters; calyx narrowly ovoid or oblong, 5-toothed; petals clawed or
unappendaged, stamens 10, styles 2, pod 1-celled or incompletely
2 or 4-celled and 4-toothed at the apex.

Distribution.—About 40 species in Europe, Asia, and Northern
Africa. Saponaria officinalis is frequently cultivated in old gar-
dens. The mucilaginous juice forms a lather with water and is
valuable for taking grease spots out of woollen cloth. Commonly
escaped from gardens to roadsides and railway embankments in
many parts of Iowa but especially in northeastern and eastern
Towa.

Extermination.—Though this weed is a perennial it is not diffi-
cult to destroy in cultivated fields and gardens. In lawns and
places where the soil is not cultivated it is best to dig up the
patches, remove the dirt from the roots and let the sun dry them;
covering with tarred paper will kill the weed, if it is kept covered
long enough, say from 6 to 8 weeks.

PORTULACACEAE, PURSLANE FAMILY.

This family contains the well known moss rose, spring beauty, ete.

DESCRIPTIVE MANUAL er 135

SS

SS aS = =
x Wee
So eee
.3 =
Nas Z
\ .

Eee =
Y)}
l Why

Fic. 76. Bouncing Bet, Soapwort (Saponaria officinalis).

136 WEED FLORA OF IOWA

BADR
Mae
annSoRe:
ele | yal
Panacea

AMBER

Fic. 77. Bouncing Bet (Saponaria officinalis). Near a building. Seeds mature
and spread from such places.
(Photographed by Charlotte M. King.)

Pusley, Purslane (Portulaca oleracea L.).

Description.—A fleshy, prostrate, smooth annual with scattered
obovate or wedge-shaped leaves; small sessile flowers with a 2-cleft
calyx; 5 small, yellow petals, inserted on the calyx; stamens 7-12,
style deeply 5-6-parted ; seeds small, finely rugose.

DESCRIPTIVE MANUAL : 137

Fic, 78. Purslane or Pusley (Portulaca oleracea). Gardens and corn-fields.
(After Clark and Fletcher.)

138 WEED FLORA OF IOWA

Fig. 78-A. Distribution of Purslane.

Distribution.—Purslane is native to Europe and is common from
the Atlantic to the Pacific especially in cultivated soil. Common
everywhere in the state in gardens and in corn fields.

Extermination.—Purslane is not difficult to exterminate if the
green weeds are placed in piles or removed from the garden. They
may be fed to hogs. It should be said that the leaves and stems
show considerable vitality, since the whole plant is fleshy. Fletcher
and Clark say: ‘‘A three-year rotation, including summer-fallow
directly after the removal of a crop of early clover, followed by a
hoed crop and again by cereal grain for the third year, will keep
it in check. If given access to corn and potato fields, sheep will feed
on late plants, and if their pasture is short, will prevent many of
them from seeding.’’

Chemical Composition—According to a report of the Bussey In-
stitution* the chemical composition is as follows:

FRESH OR AIR DRY MATERIAL.

. 5 Nitrogen free
Water | Ash | Protein | Fiber | aTIne: Fat
92.61 | 1.56 | 2.24 | 1.03 | 2.16 0.40
WATER FREH SUBSTANCE.
| 21.1 | 80.2 | 19.9 | 29.4 | 5.4

*Bull. 1877: Jenkins and Winton, Bull. Off. Exp. Sta. 11.

DESCRIPTIVE MANUAL 13$

RANUNCULACEAE, BUTTERCUP FAMILY.

The plants of this family are acrid. There are few economic
plants among them; some like the peony, columbine, buttercup, lark-
spur, and aconite are cultivated for ornamental purposes.

Small-flowered Crowfoot (Ranunculus abortivus L.).

Description.—A small, slightly pubescent, succulent biennial;
from 6 in.-2 ft. high with multiple roots; root leaves roundish or
kidney-shaped, crenate; stem leaves often 3-5-lobed or parted, mostly
toothed ; petals small, pale yellow; shorter than the reflexed calyx;
carpels minute.

Fie. 79. Crowfoot (Ranunculus abortivus). Common in woodland pastures,
pastures.
(Photographed by Hart.)

140 WEED FLORA OF IOWA

aes
CEP EE SN

fer

Fic. 79-A. Distribution of Crowfoot.

Distribution—Common everywhere in Iowa in waste places
along roadsides and in fields, occasionally eastward to Newfound-
land, south to Florida and north to Manitcba, also in the Rocky
mountains.

Extermination.—This weed is easily exterminated by cultivation.

Swamp Buttercup (Ranunculus septentrionalis Poir.).

Description.—A branching, prostrate, smooth or sometimes pubes-
cent perennial with multiple fibrous roots, frequently rooting at

the nodes and often forming long runners; leaves large, petioled,
8-divided, divisions mostly cuneate, petals obovate, larger than the
spreading calyx; achenes flat, strongly margined, pointed by a stout
straight beak.

Distribution —Common in fields, especially low grounds from
eastern Canada to Manitoba; south to Kansas and Kentucky. Com-
mon everywhere in Iowa in low places in Story, Boone, Marshall,
Polk, Linn, Clinton, Buchanan, Emmet, Worth, Woodbury, Potta-
wattamie, Plymouth, Kossuth, Dallas and Allamakee counties.

Extermination—Drainage of the soil and thorough cultivation
will soon exterminate this weed.

DESCRIPTIVE MANUAL ~ 141

Fic. 80. Creeping Buttercup (Ranunculus septentrionalis). Common in low
grounds. Flowers yellow.
(Photographed by Hart.)

Fie. 80-A. Distribution of Creeping Buttercup.

142 WEED FLORA OF IOWA

Prairie Larkspur (Delphimum penardi Huth.).

Description.—A perennial pubescent or hairy herb, more or less
glandular above, with simple, erect stem, 3-5 ft. high; leaves 3-65
parted, divisions 2-3 cleft; the numerous flowers white, or bluish-
white, in elongated raceme, spur ascending or erect; follicle many-
seeded. :

Distribution.—F rom Illinois and Wisconsin, westward and north-
ward. Common on gravelly knolls along railroads throughout the
state of Iowa.

Extermination.—This perennial is easily exterminated by culti-
vation. The roots of the plant readily succumb when exposed to
the sun.

Fic, 80-B. Prairie Larkspur (Delphinium penardi). Common on gravelly knolls.
(Drawing by Ada Hayden.)

CRUCIFERAE, MUSTARD FAMILY.

This family contains the well known sweet alyssum, cabbage, cauli-
flower, rape, radish, turnip, white and black mustard, water cress,
ete. They are all pungent herbs. ee eat ey

ee DESCRIPTIVH MANUAL " 143

Pennyeress (Thlaspi arvense L.).

Description.—An annual or winter annual with simple, smooth,
erect or branching stem; leaves of stem clasping, with arrow-shaped

wie peengi ip yee a atk
STINAWEED on FIELD PENNYSG

Yeioe 3

Fie. 81. Stinkweed or Wield Pennycress (Thlaspi arvense). Grain and clover
fields.
(After Clark and Fletcher.)

144 WEED FLORA OF IOWA —

Fic. 81-A. Distribution of Pennycress.

base ; root leaves petioled; flowers white; petals nearly equal; seeds
purplish brown, longer than broad; cotyledons accumbent.

Distribution—Common in waste places, particularly in clover
fields; Story, Woodbury, Winneshiek, Allamakee and some other
counties in the state. Common in Manitoba, Minnesota, Dakota, and
eastern Canada, particularly in the prairie provinces. The weed
is abundantly distributed by spring floods and also to some extent
by clover seed.

Large Peppergrass (Lemdium virginicum L.).

DescriptionAn erect annual, at first quite simple, later much
branched, 8 in.-2 ft. high; leaves divided, entire or with irregular,
pointed teeth; flowers small, white; pod circular or oval with a lit-
tle notch at the upper end; seeds light brown, elongated, with a
prominent ridge on one side,.on addition of water becoming muci-
laginous; cotyledons accumbent.

Distribution.—Large pepperegrass is native to the Mississippi val-
ley, east to New England; more common in Missouri, Illinois and
Ohio. It is widely scattered in Iowa, being particularly common
in timothy meadows in some years.

Extermination—tThis peppergrass sometimes comes up abund-
antly in the fall. The fields should, therefore, be plowed in the fall
and when sowing small grain given a thorough dragging. In corn
fields the ordinary methods of cultivation will destroy the weed.
Do not permit any of the plants to seed. Frequent in timothy seed.
Sow only clean timothy seed.

DESCRIPTIVE MANUAL 145

Fic. 82. Large or Virginia Peppergrass (Lepidium virginicum). Common in
flelds, gardens, ete.; along roadsides.
(Photographed by Colburn.)

Fig. 82-A. Distribution of Large Peppergrass.

10

146 WEED FLORA OF IOWA

Small Peppergrass (Lepidium apetalum Willd.).

Description—Much like the foregoing, an annual 8 in-2 ft. high,
but leaves and pods smaller; flowers small, greenish; seeds light

Fic. 83. Small Peppergrass (Lepidiwm apetalum). Common in timothy
meadows, fields, ete.
(After Clark and Fletcher.)

DESCRIPTIVE MANUAL . 147

Fie, 83-A. Distribution of Small Peppergrass.

brown, elongated, with prominent ridge on one side, becoming muci-
laginous when moistened with water; cotyledons incumbent.

Distribution—Small peppergrass is common in the northern
states from New England across the continent; apparently native
in the west ; in the east introduced from Europe. It is abundant in
fields and waste places. In some years it is particularly common in
timothy and clover meadows.

Extermination.—The peppergrasses are not difficult to extermin-
ate in cultivated fields since they are annuals. In growing timothy
seed it is important above all to have a field as clean from weeds
as possible. Timothy should therefore be sown in a field that has
been under thorough and clean cultivation for several years and
clean seed only should be used. In this way the peppergrass can
largely be prevented from growing.

Fletcher and Clark make the following suggestions: ‘‘Only
autumn plants which live through the winter give trouble in grain.
Thorough surface cultivation in the spring, with the plow, disc or
broad-shared cultivator, is efficacious. Immature seeds may ripen
in the pods when plowed down.’’

Hoary Alyssum (Berteroa incana (l.) DC.).

Description.—A tall, green, erect annual or biennial with entire,
pubescent, pale green, lanceolate leaves; flowers white, 2-parted;
pods canescent.

148

Fic. 84.

WEED FLORA OF IOWA

Hoary Alyssum (Berteroa incana); a, flowering stem; b, flower; c,
pods; d, section of ovary. Weed of clover fields.

Fig. 84-A. Distribution of Hoary Alyssum.

DESCRIPTIVE MANUAL 149

Distribution —Said to be common in northeastern United States
and becoming frequent in other Atlantic states ; found in Mississippi
and adjacent states; found not infrequently in Iowa; reported from
Ida county in 1912, and said to have been introduced with clover
seed.

EHatermination.—Sow clean clover and alfalfa seed. Succumbs
readily to cultivation.

False Flax (Camelina sativa Crantz.).

Description.—An erect annual with single or sparingly branched
stem, 114 ft. long, smooth or slightly pubescent stellate hairs; leaves
erect, lanceolate or arrow-shaped, entire or nearly so; flowers small,
yellow, pedicels in fruit spreading ; pod obovoid 4-6 in. long, smooth,
reticulated, margined from beak down along placental side with
smaller ribs between them; seeds light brown, 1 line long, minutely
pitted, caulicle prominent, running lengthwise with a prominent
groove between it and the cotyledons which are incumbent; on the
addition of water seeds become mucilaginous.

Distribution —This weed is particularly common in the grain
growing sections of the north, as Dakota, Manitoba and Saskatche-
wan. In recent years it has become more common in Iowa, par-
ticularly in the northern counties.

Extermination—Clark and Fletcher recommend the following
treatment: ‘‘When a crop of winter wheat is infested with false
flax, harrowing in the spring kills the young plants without injur-
ing the wheat. A thorough summer-fallow, with cultivation the pre-
vious fall and continuous cultivation throughout the summer, is
recommended for fields badly infested with this. weed.’’

150 WEED FLORA OF IOWA

Fig. 85. False Flax (Camelina sativa). In grain and flax fields, waste places.
(After Clark and Fletcher.)

DESCRIPTIVE MANUAL 151

Fig. 85-A. Distribution of False Flax.

Shepherd’s Purse (Capsella bursa-pastoris Moench.)

Description.—An annual or winter annual 1-114 ft. high; root
leaves clustered, nearly divided or merely toothed; stem leaves ses-
sile; flowers small, white, in fruit spreading ; pods much wider above
than below, many-seeded ; seeds light brown, elongated, with a promi-
nent ridge, mucilaginous when moistened with water; cotyledons
incumbent; trichomes stellate, roughened.

Distribution.—Shepherd’s purse is native to Europe and one of
the most common early spring flowers from the Atlantic to the Pa-
cific. Common everywhere in gardens and fields in the state.

Extermination.—Clark and Fletcher state: ‘‘It has an enormous
power of propagation; a single plant will ripen 50,000 seeds. Waste
places should be cleared as far as practicable and seeded to grass.
It does not give serious trouble on lands worked under a short rota-
tion, with clean cultivation of hoed crops. Sow clean grass and
clover seeds. ’’

152 WEED FLORA OF IOWA

Fig. 86. Shepherd’s Purse (Capsella bursa-pastoris). Common in gardens,
fields and waste places.
(After Clark and Fletcher.)

DESCRIPTIVE MANUAL 153

2 Ap: | ;

Figure 86A Figure 86B

Fig. 86-A. Plant hair or trichome of Shepherd’s Purse.
(Drawing Charlotte M. King.)

Fig. 86-B. Distribution of Shepherd’s Purse.

Wie. 86-C. Shepherd’s Purse (Capsella bursa-pastoris). Weed in city streets.
(Photographed by Charlotte M. King.)

Jointed Charlock (Raphanus raphanistrum L.).

Description.—Biennial or annual, having a slender root, rough
leaves, lyrate, pinnatifid, with a large terminal lobe; flowers yel-
lowish fading to white, or purplish veined; pods linear or oblong,
jointed, 2-8-seeded.

154 WEED FLORA OF IOWA

WHET? DARDIOM as FDINT
WILD RADISH of oC

Wig. 87. Wild Radish or Jointed Charlock (Raphanus raphanistrum). In oat
fields in northern Iowa.
(After Clark and Fletcher.)

DESCRIPTIVE MANUAL 155

Fig. 87-A. Distribution of Jointed Charlock.

Distribution.—Common ; spreading eastward in fields and waste
places; reported in grain fields in Worth and a few other counties
in the northern part of Iowa. It is said to have been largely dis-
tributed with oats seed.

Extermination.—Exterminated by cultivation. Sow only clean
oats seed in clean fields.

Mustard or English Charlock (Brassica arvensis (Li.) Ktze.).

Description.—Lower leaves nearly divided to the middle, with
divisions unequal, terminal lobe larger, upper leaves not stalked
as a rule, much smaller than the lower; flowers yellow, large and
very fragrant; pods 1-2 in. long, irregular in outline, appearing
somewhat nodose, 3-7-seeded or occasionally more, upper part of pod
forming a beak; seeds round, brownish black, darker than in B.
migra and minutely pitted, when moistened becoming mucilaginous.

Distribution —Mustard or charlock has been known as a pest of
the grain fields from the earliest historical record, throughout the
erain growing section of the world; common everywhere in Iowa,
but most abundant in the grain growing section of northern and
northwestern Iowa where it was introduced with flax.

Extermination.—The first and most important consideration in
connection with the extermination of mustard is that the oats or
wheat should be freed from mustard seed. Then this grain should
be sown on clean fields, preferably fields that have been in pasture
or meadow. Nothing has done so much to remove the weeds from
the fields of northwestern Iowa as the pasture and meadow. If the
grain is sown in a corn field there should have been no mustard the

156 WEED FLORA OF IOWA

-Fig. 88. Wild Mustard or Charlock (Brassica arvensis). Common in road-
sides and grain fields.
(After Clark and Fletcher.)

DESCRIPTIVE MANUAL 157

Fig. 88-A. Distribution of Wild Mustard.

previous season. Having sown the small grain on a clean field there
is always a chance that some of the seeds.will retain their vitality
in the soil. If much of this mustard should come up it may become
necessary to spray it with iron sulphate. Where the mustard is
abundant this is a very effective means of destroying the weeds,
using the sulphate at the rate of 100 pounds to a barrel of water.

Chemical Composition.—According to the University of Minne-
sota the chemical composition is as follows :*

Nitrogen free
Dry Matter Crude Protein Ether Extract earaeh and Ash
er
91.79 | 15.75 1.55 | 15.59 | tell

Black Mustard (Brassica nigra Koch.).

Description.—A tall, coarse, much-branched annual, 2-5 ft. high ;
leaves variously divided or only deeply cut, the terminal lobe the
largest, sharply toothed, upper leaves small, simple, as a rule linear;
leaves as a rule not smooth, but somewhat bristly, at least on the
veins; flowers yellow, smaller than in charlock; pods smooth, about
1% in. long, 4-cornered, tipped with a slender beak; seeds black or
reddish brown, smaller than in charlock; cotyledons incumbent;
trichomes not stellate, simple, rough.

"Snyder: Bull. Minn. Agr. Exp. Sta., 101.

158 WEED FLORA OF IOWA

Fig. 89. Black Mustard (Brassica nigra). Fields, gardens and roadsides.
(Photographed by Colburn.)

Fig. 89-A. Distribution of Black Mustard.

DESCRIPTIVE MANUAL 159

Distribution —This weed is common in the northern states and
extends across the continent. It is abundant in Iowa, at times, in
waste places and vacant lots; apparently, however, it is less com-
mon than common charlock.

ExterminationThis weed can he exterminated by the same
method that is used with common charlock.
Rocket (Eruca sativa L.).

Description—An annual or biennial herb with stout, 4-sided
stem; lower leaves lyrate, incised or pinnatifid, upper leaves,

Fig. 90. Rocket (Hruca sativa). Introduced with alfalfa seed.
(Drawn by F. C. Collins.)

160 WEED FLORA OF IOWA

Fig. 90-A. Distribution of Rocket.

smaller, lobed, or entire ; flowers white or yellowish-white with dark
veins; fruit an oval, elongated silique containing many, more or
less compressed, seeds in 2 rows.

Distribution.—A native of western Asia and the Mediterranean
region, but cultivated as a salad plant and often an escape. Intro-
duced into Iowa with alfalfa seed in Woodbury, Plymouth, O’Brien,
Clay, Mitchell, Pottawattamie, Mills, Ida, and Sae counties.

Extermination.—The weed can be exterminated by cutting the
plants off a few inches below the surface of the ground or by giving
thorough cultivation.

Hare’s-ear Mustard (Conringia orientalis (Li.) Dumort.).

Description—Shghtly succulent annual; leaves light green, ses-
sile, obtuse, racemes becoming elongated in fruit; petals much
longer than the sepals; pods long, linear 4-angled, spreading; coty-
ledons incumbent.

Distribution.—Common eastward and appearing in the Missis-
sippi valley; occurring in Woodbury, Webster and Page eons
and probably in many other places in Iowa.

Extermination.—Easily exterminated by cultivation.

DESCRIPTIVE MANUAL 161

OAT ALLSTAR H

Fic. 91. Hare’s-ear Mustard (Conringia orientalis). In grain fields, and waste
places in northwestern Iowa.
(After Clark and Fletcher.)

i

162 WEED FLORA OF IOWA

SE
SOSA aS
acer

ing stem, seed
e’s-ear Mustard (Conringia orientalis). Flower
noe aa eae aan of seed. Appearing in several counties in Iowa.

DESCRIPTIVE MANUAL ‘ 163

Ball Mustard (Nesha paniculata (L.) Desv.).

Description —An. erect, slender annual or biennial, 1-3 ft. high
with stem simple up to the inflorescence; stem and leaves, both
being covered with stellate pubescence; sessile leaves oblong, very

Fic. 91-C. Ball Mustard (Neslia paniculata) ; a, flowering stem; b, pod; ec, seed.
(Schuyler Mathews in Mich. Agr. Exp. Sta. Bull.)

narrow, sagittate at base; racemes elongate; flowers small, yellow,
about 1 in. in diameter; seed-pods nearly spherical, 2-celled with
1 small yellow seed in each cell, sometimes but one developing.

Distribution.—In grain fields, Canada, the Dakotas and occa-
sionally in northwestern Iowa.

Extermination.—Clean seed; easily destroyed by cultivation.

164 WEED FLORA OF IOWA
Hedge Mustard (Sisymbrium officinale (L.) Seop.).

Description.—A slender, erect annual or winter annual, 114-214
ft. high ; lower leaves divided, upper entire or hastate at base ; flow-
ers small, yellow, borne in spikelike racemes; seeds small, brown;
cotyledons incumbent.

Distribution.—F ound everywhere in the state, notably in Story,
Boone, Polk, Clinton, Linn, Marshall, Hardin, Black Hawk, Wood-
bury, Pottawattamie, Carroll, Jasper, Monroe, Scott, Lee, and Alla-
makee counties.

Extermination—Hasily exterminated by cultivation; also by us-
ing the formula 100 pounds of iron sulphate to one barrel of water.

Fig. 92. Hedge Mustard (Sisymbrium officinale). Common in gardens, fields
and waste places.
(General aspect of plant photographed by Hart. Drawing by Charlotte M. King.)

DESCRIPTIVE MANUAL 165

Fig. 92-A. Distribution of Hedge Mustard.

Chemical Composition.—According to the University of Minne-
sota it is as follows :*

Nitrogen free
Dry Matter Crude Protein Ether Extract extract and Ash
er
94.5 | 16.52 | 1.43 | 74.18 | 7.87

Tumbling Mustard (Sisymbrium altissimum L.).

Description.—A leafy, branched annual from 1-4 ft. high, lower
leaves runcinate, pinnatifid, irregularly toothed, or wavy margined,
upper leaves smaller, threadlike.

Distribution.—This weed is native to east Europe. It has become
widely scattered in the northern states, particularly in the west from
Minnesota to Washington and in Canada. It is widely scattered in
Towa in the vicinity of railroad watering tanks, elevators and stock-
yards. It is less common in the southern half of the state.

Extermination —The young mustard plants are easily killed by
eultivation. They are likely to occur in some commercial seed like
timothy, therefore, sow only clean seed.
eaerre eal Wind’ Aer wep Sta. tor:

166 WEED FLORA OF IOWA

Fig. 93. Tumbling Mustard (Sisymbrium altissimwm). In grain fields, rail-
ways, ete.
(After Clark and Fletcher.)

DESCRIPTIVE MANUAL 167

Pe
aes q
haan
ppeas
Se <=

Wig. 93-A. Distribution of Tumbling Mustard,

Marsh Cress (Radicula palustris (.) Moench.).

Description.—An annual or biennial; erect, smooth, or slightly
pubescent herb; from 1-114 ft. high; leaves pinnately cleft or
parted, pinnatifid; the lobes toothed; upper leaves sessile; flowers
yellowish in racemes; pods ellipsoid or ovoid.

Fig. 94. Marsh Cress (Radicula palustris). Common in low grounds.
(Photographed by Colburn.) -

168 WEED FLORA OF IOWA

Cea
: HP BS
Gener woes
Bot

Fig. 94-A. Distribution of Marsh Cress,

Distribution —In wet places or in low grounds; frequent in oat
fields and meadows; abundant in Iowa especially in northern Iowa;
common throughout the northern United States. Not infrequently
distributed with clover seed that is grown in Iowa.

Extermination.—This weed may be exterminated by first drain-
ing the soil and then giving clean cultivation.

Horseradish (Radicula armoracia (L.) Robinson).

Description—A. stout perennial with long, deep roots; leaves
large, oblong, crenate or pinnatifid, the latter produced in the
spring; stem leaves lanceolate, or oblong cordate; flowers with 4
green sepals and 4 white petals, not common; pods short, globular,
but fruit seldom found. At least I have never observed any in lowa.

Distribution. Horseradish is native to eastern Europe and in-
troduced in west Europe and the United States; common from the
Atlantic to the Pacific; largely an escape from cultivation; found
in every part of Iowa.

Extermination.—The horseradish is one of the most persistent
of our weeds; no other weed will stand such rough treatment. It
may be hoed and cultivated and still it persists in coming up. Some
years ago we tried the following plan: The land was plowed, then
harrowed ; the roots were picked up and the process repeated after
the lapse of a week, when young plants again made their appear-
ance. After that, young plants were cut off with a hoe below the
ground as soon as they appeared. This treatment was kept up for

DESCRIPTIVE MANUAL ms 169

Fic. 94-B. MHorseradish (Radicula armoracia). Escaped from cultivation; a
rather persistent weed.
(Drawing by Charlotte M. King.)

Fig. 94-C. Distribution of Horseradish.

two years, and in this way most of it was removed. Quack grass
near the horseradish received the same treatment and was killed in
a single season, the season being dry. Very little progress in de-
stroying the plant would have been made in a wet season.

170 WEED FLORA OF IOWA
Winter Cress (Barbarea vulgaris R. Br.).

Description.—A biennial, with yellow flowers 1-2 ft. high; stem
furrowed, simple or branched; lower leaves simple or pinnately
parted, terminal lobe the largest, round or ovate; upper leaves obo-
vate, cut, toothed or pinnatifid at the base; flowers bright yellow;
pods erect or slightly spreading; cotyledons accumbent.

Distribution—HEHastern North America from Labrador to Mary-
land, Iowa, Manitoba, Rocky Mountains, Pacific slope; common in -
northern Iowa. A cosmopolitan weed in Europe, Asia, Africa and
Australia.

Extermination.—This perennial weed is not difficult to kill if the
field is given an early plowing followed by a subsequent disking and
harrowing, thus getting the field in a good state of tilth for a crop.

Fig. 95. Winter Cress (Barbarea vulgaris).
(Photographed by Colburn.)

DESCRIPTIVE MANUAL 171

Fig. 95-A. Distribution of Winter Cress.

CAPPARIDACEAE, CAPER FAMILY.

This family contains the caper which is used for pickling, the
Rocky Mountain bee plant, ete.

Stinkweed (Polanisia graveolens Raf.).

Description.—A fetid annual with glandular hairs; leaves with 3
oblong leaflets; flowers in leafy racemes; 6 petals, white, with claws,
notched at the apex ; stamens about 11, scarcely exceeding the petals;
not elongated, bearing a gland behind the base of the ovary; pod
short, stalked ; seeds rough. The P. trachysperma T. & G. has larger
flowers with long exserted stamens and sessile pods.

Distribution—Iowa to Kansas and eastward to New England;
common in sandy soil, railroad embankments, Muscatine Island.

Extermination.—EKasily exterminated by cultivation. The land
should be cultivated as soon as a fresh growth of the weed develops.
Great care must be taken not to plow down any full-sized pods, even
though they may be green, as it has been proven that in the dry
climate of the west such seeds can ripen beneath the soil. The most
important measure to be used in order to clear the land of stink-
weed is harrowing the growing crop to kill the seedlings. The har-
rowing should commence before the crop emerges from the ground
and be repeated when the grain is about three inches high.

172 WEED FLORA OF IOWA

Fig. 96. Clammy Weed or Stinkweed (Polanisia graveolens). In sandy places,
gravelly soils, ete.
(Photographed by Hart.)

Fig. 96-A. Distribution of Stinkweed.

DESCRIPTIVE MANUAL 173

Fig. 97. Stinkweed (Polanisia trachysperma). Common in sandy soils, rail-
way embankments and gravelly soils.
(Photographed by Colburn.)

Rocky Mountain Bee-plant or Stinking Clover (Cleome serrulata
Pursh.).

DescriptionA smooth annual; leaves of 3 lanceolate, oblong
leaflets, somewhat fleshy; flowers in bracteate racemes; petals
usually rose-colored, short-clawed ; stipe of pod as long as the pedicel.

Distribution—From western Iowa, Minnesota and northward,
Utah, Colorado, Montana and westward; common in Iowa in Fre-
mont, Mills, Pottawattamie, and Woodbury counties, occasionally

eastward in Polk county.

Extermimation.—KHasily exterminated by cultivation.

174 WEED FLORA OF IOWA

Fig. 98. Rocky Mountain Bee-plant (Cleomeg serrulata). Fields, roadsides in
western Iowa.
(Photographed by Colburn.)

Fig. 98-A. Distribution of Rocky Mountain Bee-plant.

DESCRIPTIVE MANUAL 175

Wy Dp ZY
Ry V \
q te
eV
EN’ hy as

Fig. 98-B. Rocky Mountain Bee-plant (Cleome serrulata).
(Drawing by Charlotte M. King.)

ROSACEAE, ROSH FAMILY.

This family contains the well known rose, apple, pear, quince,
plum, peach, almond, strawberry, blackberry, raspberry, spiraea,
ete.

Cinquefoil, False Strawberry (Potentilla monspeliensis L.).

Description.—A hairy annual or winter annual from 1-214 ft.
high; leaves 3-foliolate, leaflets obovate to oblanceolate, the upper-
most toothed, nearly the whole length; flowers in close cymes, calyx
large, 5-cleft with 5 bractlets; petals 5, yellow, small; stamens 15-20;
style terminal ; trichomes simple, long pointed, thick walled.

Distribution —Naturalized from Europe; eastern Canada, New
England, to Kansas; common in Iowa, in Story, Boone, Polk, Clin-
ton, Lyon, Carroll, Woodbury, Kossuth, Webster, Marshall, Cerro
Gordo, Worth, Winnebago, Allamakee and other counties.

Extermination —Frequently introduced with clover seed. Sow
only clean clover seed in a clean field. Cut the weed off below the
surface of the ground and give thorough cultivation.

176 WEED FLORA OF IOWA

Fic. 99. Cinquefoil, False Strawberry, Five-finger (Potentilla monspeliensis).

Common in gardens, timothy meadows, etc. a, Plant hair; b, showing cell-wall.

(a and b, drawn by Charlotte M. King, general aspect of plant photographed
by Hart.)

Fig. 99-A. Distribution of Cinquefoil.

DESCRIPTIVE MANUAL 177

Silverweed (Potentilla anserina L.).

Description.—Herbaceous perennial, spreading by slender run-
ners; numerous white-tomentose and silky-villous leaves, all radi-

Fig. 100.. Silverweed (Potentilla anserina). In marshes.
(Drawing by Ada Hayden.)

Fig. 100-A. Distribution of Silverweed.

12

178 WEED FLORA OF IOWA

cal; pinnate leaflets, 7-21 with smaller ones between, oblong, sharply
serrate, silky-tomentose beneath ; flowers with 5 bright yellow petals;
peduncles elongated ; styles filiform.

Distribution—Common eastward in brackish marshes; also in
the Dakotas and the Rocky mountains; common in Wright county,
Iowa; perhaps in other places.

Extermination.—Give a shallow cultivation; expose the roots to
the sun. Care must be used to kill the weed on its first appearance
as it is quite persistent.

Wild Rose (Rosa pratincola Greene).

Description—Low shrub with very prickly stem; compound
leaves of 7-11 leaflets, broadly elliptical to oblong-oblanceolate, sub-
cuneate at base, short stalked or sessile, serrate; stipule narrow,

Fig. 101. Wild Rose (Rosa pratincola). Grain fields, roadsides.
(Photographed by Colburn.)

DESCRIPTIVE MANUAL 179

ae ee = et

Fig. 101-B. Wild Prairie-rose (Rosa pratincola).
(Drawn by Ada Hayden.)

180 WEED FLORA OF IOWA

glandular toothed; flowers corymbose, calyx tube urn-shaped, 5
sepals, smooth or occasionally hispid, petals 5, rose-colored; fruit
oblong, ovaries hairy.

Distribution—Common in prairies and field from Texas to Min-
nesota, west to Colorado. Common everywhere in Iowa; Story,
Polk, Emmet, Dickinson, Palo Alto, Clay, Kossuth, Winnebago,
Allamakee, Clinton, Muscatine, Scott, Decatur, and Pottawattamie
counties.

Extermination—tThis weed often persists in grain fields of
northern Iowa. Thorough cultivation for a few seasons will, how-
ever, usually destroy the weed.

Stickweed (Geum canadense Jacq.).

Description.—A perennial herb from 114-2 ft. high; leaves pin-
- nate, the lower of 3-5 leaflets or undivided; stem leaves 3-divided or
3-lobed, sharply toothed ; stipules ovate-oblong ; flowers white; calyx
bell-shaped ; deeply 5-cleft; petals 5; stamens many; pistils numer-
ous; styles joimted and bent near the middle, the upper part falling
away and the lower part hooked.

Distribution Widely distributed in northern United States, and
frequently found in woods or fields adjacent thereto; common espe-
cially in northeastern Iowa.

Extermination.—This weed is easily scattered by animals because
of the hooked achenes; thorough cultivation will, however, destroy
it.

LEGUMINOSAE, PULSE FAMILY.

This family contains the clover, pea, beans, ecwpea, soybean,
honey locust, lupines, vetches, coffee bean, senna, and ornamental
plants as red bud, sweet pea, caragana, etc.

DESCRIPTIVE MANUAL 181

Fig. 102. Stickweed, White Avens (Gewm canadense). White flowers with bur-
like fruit scattered -by animals. In pastures and fields.
(Photographed by Hart.)

182 WEED FLORA OF IOWA

Rattle-box (Crotalaria sagittalis L.).

Description.—A hairy annual from 3 in-1 ft. high, with a small
tap root; stem branched, villous, terete or wing-margined; leaves
oval or oblong-lanceolate, from 14-14 in. wide, edge of the leaf en-
tire or somewhat wavy and hairy; stipules united and decurrent
on the stem, becoming inversely arrow-shaped; peduncles produce
a few yellow flowers about 14 in. in diameter; calyx 5-cleft, stand-
ard of the flower large, heart-shaped; keel scythe-shaped; stamens
monadelphous, anthers of two sizes, 5 smaller and roundish; pod
large, inflated, bears a close resemblance to that of the garden pea,
greenish at first, becoming blackish varying in size from 34-1 in.
in length and about 1 in. in diameter; seeds from 14-1/10 in. in
diameter, flattish, kidney-shaped, when mature breaking away from
the point of attachment and rattling in the pod, hence the name
‘‘rattle-box’’.

Fig. 103. Rattle-box (Crotalaria sagittalis). Common in sandy soil, Missouri
river bottoms.
(Photographed by Colburn.)

DESCRIPTIVE MANUAL 183

~ Fy

es
ase

Fig. 103-A. Distribution of Rattle-box.

Distribution. Common from New England to Minnesota, south-
west to North Texas. In Iowa abundant only along Missouri river,
the Des Moines near Ft. Dodge, and at other points along sandy
beaches of our streams.

Extermination—This weed occurs mostly in the Missouri bot-
toms, generally on more or less sandy soil. It succumbs readily to
cultivation. The raw sandy prairies on which it occurs should be
broken up and sown to some leguminous crop, like alfalfa, which
will crowd the weed out.

The Yellow Clover (Trifolium agrarium L.).

Description—A smoothish annual, usually upright, with obovate-
oblong leaflets, all 3 from the same point (palmate) and nearly ses-
sile; stipules narrow; corolla yellow, persistent.

Distribution—Common in sandy fields and roadsides from east-
ern Canada west to Wisconsin and Minnesota and to lowa; common
along roadsides in northeastern Iowa.

Extermination.—Same as for low hop-clover.

184 WEED FLORA OF IOWA

Fig. 104. Yellow or Hop Clover (Trifolium agrariuwm). Along roadsides. Yel-
low flowers.
(Photographed by Colburn.)

Low Hop-clover (Trifolium procumbens L.).

Description—A pubescent annual with spreading or ascending
stems; leaves of 3 leaflets pinnate, the lateral at a small distance
from the other, obovate, notched at the end; stipules ovate, short;
flowers yellow, persistent, becoming dry in age.

Distribution.Naturalized from Europe; common in eastern
states.

Extermination.—Readily succumbs to cultivation. The seeds,
however, may retain their vitality for some time in the soil. Sow
clean seed in clean soil.

DESCRIPTIVE MANUAL 185

Fig. 105. Low Hop-clover, Yellow Clover (Trifolium procumbens). Clover
fields, meadows, waste places.

(1. Drawn by Charlotte M.*King, the general aspect photographed by Hart.)

Fig. 105-A. Distribution of Low Hop-clover.

186 WEED FLORA OF IOWA
Yellow Sweet Clover (Melilotus officinalis (.) Lam.).

Description—An upright, usually tall, fragrant annual cr bien-
nial; leaves compound, leaflets obovate-oblong, obtuse, closely ser-
rate; flowers yellow, pod smooth, prominently cross-ribbed. The
M. indica also with yellow flowers has a gibbous and alveolate pod.
This has recently been introduced.

Distribution.—Yellow sweet clover is also native to Europe.
Widely scattered throughout the United States, more abundant upon
the Pacific coast, in the Great Basin country and the Rocky moun-
tains. Not abundant in the northern Mississippi valley. More or
less frequent in many parts of Iowa, however, as in Humboldt and
parts of Greene and Woodbury counties.

Fig. 106. Yellow Sweet Clover (WMelilotus officinalis). Roadsides, streets and
some fields.
(Photographed by Colburn.)

DESCRIPTIVE MANUAL 187

Fig. 106-A. Distribution of Yellow Sweet Clover.

Extermination.—The seeds preserve their vitality for some time.
The weed is easily destroyed by cultivation.

Sweet Clover (Melilotus alba Lam.).

Description.—An erect annual or biennial 2-4 ft. high; rather dis-
tant, compound leaves, leaflets obovate, oblong, obtuse, serrate, nar-
rowed at the base, truncate, emarginate or rounded at the apex;
flowers with white petals, small, fragrant; pod ovoid, reticulated
and smooth.

Distribution.—Sweet clover is native to Europe and abundant in
all parts of the United States. It has been widely scattered by bee-
keepers who sowed it as a honey-bee plant. Abundant now along
highways, right of ways of railways; also in some fields; found in
every part of Iowa.

Extermination—The only way to exterminate this plant is to
prevent seed formation. This may be done by cutting the plants
underneath the ground. In fact the young plants are easily ex-
terminated in this way. The plants occur in the meadows and pas-
tures, coming largely from the weeds left growing along the road-
sides. Road overseers should see that these chance plants are re-
moved. According to a recent investigation of Prof. Ewart of Aus-
tralia some of the seeds retain their vitality for a long time, some-
times more than half a century. It is imperative, therefore, to pre-
vent the formation of seeds so as not to sow for a future generation
to eradicate. Sweet clover is used as a forage plant and considered
quite. valuable. Mr. Coverdale of Maquoketa considers it a most
valuable plant. Mr. Westgate has recently brought together many
valuable points in its favor.

188 WEED FLORA OF IOWA

Fig. 107. White Sweet Clover (Melilotus alba). Common along roadsides.
(Photographed by Colburn.)

The Farmer’s Review says regarding the plant: ‘‘In Minnesota,
Wisconsin, and Ohio there are laws against the plant known .as
sweet clover. We fail to see why this plant should be singled out
and denominated as a weed. It certainly is not objectionable as a
cover for waste places, and is easily controlled where its presence is
not desired.’’

Chemical Composition.—The chemical composition according to
the University of Wyoming is as follows.*

*Bull. No. 70 compiled by Henry G. Knight, Frank E. Hepner, chemists, and
Aven Nelson, botanist; Wyoming Experiment Station.

DESCRIPTIVE MANUAL

Fig. 108. White Sweet Clover (Melilotus alba). Along roadsides.
(Photographed by Charlotte M. King.)

[area > Wate: Fe .
© | Mitchell ellie
: 5 . S
45 .
° is MI so |e |
elie \
. \
IaiHers| * « we

Wig. 108-A. Distribution of White Sweet Clover.

189

190 WEED FLORA OF IOWA

B bs
5 a 29
z # Ge
o 4 =
Water) 2.25225 ee ee 79.35 6.02 waren
Ash) assess et oe ae ee ee eS ne 2.10 9.57 10.18
Hither. extract): =2222 28 ee ee en ee ae 0.53 2.42 2.52
Crude fiber (222s 22 ee ae eee eee ea eee 4.78 21.77 23.16
Crude: protein, | 23-222 2s ee ee el ee eee 3.96 18.00 19.15
Nitrogen, free. extractq. 2s seo ss ee Se eee 9.28 42.22 44.99

Black Medic (Medicago lupulina L.).

Description—A procumbent, pubescent, annual; compound
leaves trifoliate ; leaflets wedge-shaped, obovate, toothed at the apex;
flowers yellow, in short spikes; pods kidney-form, 1-seeded. —

Distribution.—Native from Europe, common in alfalfa fields in
the Rocky mountains and on the Pacific coast; common in waste
places in eastern North America; reported from a number of coun-
ties In Jowa, as Wright, Kossuth and Story. |

Extermination—This annual is not difficult to exterminate by
giving thorough cultivation; care should be used in planting clover
and alfalfa seed, because this weed seed is a common impurity of
the latter. The seed also retains its vitality for some time.

Chemical Composition.*

FRESH OR AIR DRY MATERIAL.

x : Nitrogen free
Water | Ash | Protein Fiber Bench Fat
78.52 | 1.37 | 3.40 | 6.31 9.20 | iar bl
WATER FREE SUBSTANOE.
| 6.4 | 15.8 | 29.3 43.4 | 5.1

*Compiled by Jenkins and Winton, Bull. Off. Exp. Sta., Bull. 11.

DESCRIPTIVH MANUAL iii

Fig. 109. Black Medic (Medicago Wwpulina). Clover and alfalfa meadows.
(Photographed by Hart.)

Fig. 109-A. Distribution of Black Medic.

192 WEED FLORA OF IOWA
Pink Parosela (Dalea alopecuroides Willd.).

Description—An erect annual from 2-3 ft. high, with pinnately-
compound leaflets; smooth flowers, whitish or light rose-color, in
cylindrical spikes; calyx villous; seeds kidney-shaped.

Distribution—F rom Minnesota to Alabama and the Rocky moun-
tains, common in western Iowa and introduced eastward in Wright,
Boone, and Story counties.

Extermination.—It is sometimes found in clover seed grown in
western Iowa, also in alfalfa seed from the west, therefore care
should be used in the selecting of seed; succumbs readily to culti-
vation.

Fig. 110. Parosela (Dalea alopecuroides). Common in western Iowa and
along railroads.
(Photographed by Quade.)

DESCRIPTIVE MANUAL 193

Fig. 110-A. Distribution of Parosela.

Rattle-box or Milk Vetch (Astragalus canadensis L.).

Description.—A tall, erect, smooth or pubescent perennial, 1-4
ft. high; leaves compound, leaflets 21-27, oblong; flowers greenish
cream-colored in spike of variable length; pods crowded, smooth,
terete, occasionally somewhat suleate; the seeds separate from the
pod, rattling, hence the common name.

Distribution—Common in the northern Mississippi valley, east
to New York and south to Georgia. Common on borders of thick-
ets, woods and native meadows.

Extermination.—This weed is easily exterminated by cultivation.

13

194 WEED FLORA OF IOWA

Fig. 111. Rattle-box (Astragalus canadensis). Woodland pastures.
(Photographed by Charlotte M. King.)

Purple or Stemless Loco Weed (Oxytropis lamberti Pursh.).

Description.—Nearly acaulescent, perennial herbs or shrubby
plants, with tufts of very numerous short stems coming from a hard
and thick root-stock containing many scaly stipules; stems and
leaves covered with silky and finely appressed hairs, or smoothish ;
leaves pinnate; leaflets linear; flowers racemose or spicate, rather
large and elongated, purple, violet, or sometimes white ; stamens dia-
delphous; keel tipped with a sharp projecting point. This is one of
the loco weeds, poisonous to cattle.

Distribution—Western Minnesota, western Iowa, and Missouri to
Texas, and New Mexico, north to British Columbia, and northwest
territory.

_Extermination.—It seldom gives much trouble in cultivated fields.

DESCRIPTIVE MANUAL 195

Fig 112. Purple Loco Weed (Oxytropis lamberti). A weed poisonous to cattle.
(Drawn by F. C. Collins.) :

Fig. 112-A. Distribution of Purple Loco Weed.

196 WEED FLORA OF IOWA
Wild Liquorice (Glycyrrhiza lepidota (Nutt.) Pursh.).

Description.—A branching perennial 2-3 feet high, leaves com-
pound of 15-19 oblong-lanceolate leaflets with mucronate points;
young leaflets sprinkled with a resinous material ; flowers in spikes;
short peduncled; whitish; pods oblong, covered with hooked
prickles, resembling a cocklebur.

Distribution—Common in the west, western lowa to Rocky
mountains, Utah, New Mexico, and Montana to Canada, also re-

bp
YY

TY

Fig. 113. Wild Liquorice (Glycyrrhiza lepidota.) Occurs in western and cen-
tral parts of the state.

DESCRIPTIVE MANUAL 197

Z a ‘ JANN Sane
ERELERERES

=

Fig. 113-A. Distribution of Wild Liquorice.

ported from the Great Lakes; commonly reported from Story,
Greene, Pottawattamie, Harrison, Monona, Fremont, and Decatur
counties.

Extermination—tThis perennial plant whose burs resemble the
cocklebur is easily exterminated by cultivation. Do not permit the
seeds to mature. Cut off the plants at the surface of the ground
to prevent flowering, if they occur in the pasture or meadow.
Where the land can be cultivated, give the ordinary plowing, fol-
lowed with harrowing to bring the roots to the surface so they are
exposed to the sun. A few days’ exposure to the sun will kill them.

Common Vetch (Victa satiwa L.).

Description.—A smooth or slightly pubescent annual from 1-21
ft. high with simple stem; leaflets 5-7 pairs, obovate-oblong to lin-
ear, notched or mucronate at the tip; 1 or 2 nearly sessile flowers
borne in the axils of the leaves, corolla violet-purple; pod linear,
several-seeded, seeds black.

Distribution —This weed has long been known as troublesome in
the grain fields of Europe, and in the northern states. It is particu-
larly abundant in northeastern and northwestern Jowa and in some
of the grain growing sections of the southern part of the state.

Extermination.—Clean seed sown in clean soil is the only method
of displacing the weed.

198 WEED FLORA OF IOWA

Fig. 114. Common Vetch (Vicia sativa). Common in grain fields, especially
wheat fields, frequently found in screenings from flour mills.
(Photographed by Colburn.)

ENE
AE

G

Fig. 114-A. Distribution of Common Vetch.

DESCRIPTIVE MANUAL 199

Chemical Composiiion.—The chemical composition of vetch (Vicia
sativa) according to U. S. Dept. Agr., 1880; p. 152, is as follows:

FRESH OR AIR DRY MATERIAL.

i=} ~~
He # 2S
= He
= 4 ay ie ur opahae a
Guiees in’ full bloom’ 2.2. | 86.20 | 1.60 | 4.14 | 2.11 | 5.34 | 0.61
WATER FREE SUBSTANCE.
| 11.6 3.00 | 15.3 | 38.7 | re

Wild Bean (Strophostyles helvola (L.) Britton).

Description.—An annual, with prostrate stem; compound leaves
ovate to oblong-obovate, with a prominent rounded lobe at the base;
corolla greenish white and purplish; pod 4-8-seeded, large, usually

- pubescent.

Distribution—Common in sandy places in northern United
States; from Wisconsin, Minnesota, and Texas east to Massachu-
setts ; common in gravel pits on Muscatine Island, along Des Moines,

Cedar and Iowa rivers.

Extermination.—Kasily exterminated by cultivation.

OXALIDACEAE, WOOD SORREL FAMILY.

This family contains the cultivated yellow and purple-flowered
oxalis. Few of the plants are economic.

200 WEED FLORA OF IOWA

Fig. 115. Wild Bean (Strophostyles helvola). Common in sandy or gravelly
soil, sandy river bottom.
(Photographed by Colburn.)

Fig. 115-A. Distribution of Wild Bean.

DESCRIPTIVE MANUAL 201
Field Sorrel (Oxalis stricta L.).

Description—aA pale green pubescent annual or perennial ; leaves
compound, with evident stipules; flowers pale yellow, cymose, 1-4,
at length deflexed ; in fruit columnar, short-pointed.

Distribution.—Common in fields and waste places from New Eng-
land to Dakota; common in Iowa probably over the entire state.

Extermmation.—Persistent cultivation and crop rotation will
usually exterminate the weed.

Fig. 116. Yellow Field Sorrel (Ozalis stricta). Common in fields. a, Trichome
or plant hair.

(a drawn by Charlotte M. King. The whole plant photographed by Hart.)

202 WEED FLORA OF IOWA

HALAL ames

ee Boe oe
US
SPENSER

wee

Fig. 116-A. Distribution of Yellow Field Sorrel.

Field Sorrel (Oxalis cormculata L.).

Description.—An erect or decumbent perennial herb, spreading
by numerous slender, pale runners; leaflets 3; flowers in cymose
clusters, yellow; peduncle ascending and sparingly pubescent.

Fig. 117. Field Sorrel (Owalis corniculata). Fields, gardens, etc.
(Photographed by Colburn. 1. Drawn by Charlotte M. King.)

DESCRIPTIVE MANUAL 203

Fig. 117-A. Distribution of Field Sorrel.

Distribution—-A very common weed in dry or moist soil through-
out eastern North America.

Extermination. —Apply the same method as to the preceding
species.

ZYGOPHYLLACHAH, CALTROP FAMILY.
A small family.

Caltrop (Tribulus terrestris L.).

Description.—The caltrop is a hairy, procumbent annual, branch-
ing from the base, producing a stem which is a foot or more long,
branches bear numerous small, compound leaves with short pe-
duncles and small stipules at the base; each compound leaf has 4-8
pairs of short-stalked leaves; small, yellow, axillary flowers about
1 in. across with peduncle much shorter than leaves; fruit very
spiny and divided into two nearly equal parts, each part consists of
2 long spines, 2 shorter and a row of very short ones, forming a
crest on the back; 5-angled, spiny fruit splits into 3-5 divisions.

Distribution.—Introduced from the Old World and oceurs from
the Atlantic states to Nebraska and Kansas; in Iowa has been found
only on Muscatine Island.

Extermination.—Caltrop is disseminated by wool, and hence the
waste of woolen mills should not be thrown in fields. The weed is
easily destroyed by cultivation.

204 WEED FLORA OF IOWA

ao YS
SR
Y FSS
4 NY
te Q My “oN
= Ae QZ ett
aS 87000 Sy
VS

Sh
=)
SS
SSH) NINN
sn
LOG»
\W Wy Zz \
( NA Wy y
NO Sk iB
AWS BIOT Ee
N
NAW a ss
XA
SU) aaa S
KG) p

¥ 1) SW_/ Nv
WINE KZ HY) rN
agoeg We pa

Ground Bur-nut (Tribulus terrestris).

waste

scil,

Sandy

Caltrop,

Fig. 118.

Muscatine Island.

(Drawing by Charlotte M. King.) *

places,

DESCRIPTIVE MANUAL | 205

Fig. 118-A, Distribution of Caltrop.

ASA

EUPHORBIACEAE, SPURGE FAMILY.

Many of the plants of this family contain an irritating milky
juice. Few are of economic importance. The poinsettia commonly
cultivated in greenhouses, snow-on-the-mountain in gardens, and
eastor-oil bean belong to this family.

Three-seeded Mercury (Acalypha virginica L.).

Description—A smoothish or hairy annual from 1-2 ft. high,
turning purple especially in the autumn; leaves ovate or oblong-
ovate, sparingly serrate, long-petioled; sterile spike, few-flowered,
pistillate flowers 1-3 at the base of staminate peduncle surrounded
by a large leaf-like bract; capsule 3-lobed, subglobular, 2-valved
earpels. .

Distribution—F rom Nova Scotia to Texas and northward to Min-
nesota. Common everywhere in Iowa along roadsides and in fields.
Especially noticeable in the fall on account of the purple bracts.

Extermination.—Three-seeded Mercury is not a difficult weed to
exterminate. The small, reddish, striate seeds are expelled from
the plant to some little distance in a manner similar to the dispersal
of the eastor-oil bean. Thorough cultivation by preventing the for-
mation of seed will eradicate the weed.

206

Fig. 119.

WEED FLORA OF IOWA’

Three-seeded Mercury (Acalypha virginica). Common in many parts
of the state.
(Drawing by Charlotte M. King.)

DESCRIPTIVE MANUAL 207

Fig. 119-A. Distribution of Three-seeded Mercury.

Spurge (Euphorbia presli Guss.).

Description—An annual from 1-144 ft. high; erect or ascending ;
leaves oblique at the base, ovate, oblong, or sometimes oblong-linear,

ala

Ct mA, X
y lp EER
: ty

ay
SS

My | Sic =
My |
i 4
|
Y,
\

Fig. 120. Spotted Spurge (Huwphorbia preslii). Common everywhere in the
state. r,
(Drawing by Charlotte M.. King.)

208 WEED FLORA OF IOWA

Fig. 120-A. Distribution of Spotted Spurge.

frequently falcate, serrate, generally with a conspicuous red spot,
or margin; flowers pedunculate in terminal cymes; appendages en-
tire; pod glabrous; seeds ovate sometimes wrinkled.

Distribution.—In loose soils and fields from New England and
Canada to Wisconsin, Minnesota and Nebraska, also southward.

Extermination—tThis annual weed is easily exterminated by cul-
tivation; therefore practice rotation of crops and give thorough cul-
tivation. Seeds of several species of this genus retain their vitality
for some length of time.

Milkweed or Creeping Spurge (Euphorbia maculata L.).

Description—Slightly pubescent or hairy annual, with prostrate
stems; leaves oblong-linear, oblique at the base; pubescent or some-
times nearly smooth, usually with a brown-red spot in the center;
serrulate above, stipules lanceolate; flowers pedunculate in lateral
clusters; glands of the involucre minute; appendages usually red;
pods acute-angled; seed sharply 4-angled with 4 shallow grooves
across the sides ; trichomes several-celled, gradually tapering to apex.

Distribution.—Found in sandy fields, or generally in fields from
New England and Canada westward; common in every part of
Towa.

Extermination.—May be exterminated in the same way as the
preceding species. ‘

DESCRIPTIVE MANUAL 209

Fig. 121. Milkweed or Prostrate Spurge (Euphorbia maculata). Sandy fields.
(Photographed by Quade. a, drawn by Charlotte M. King.)

y .
Kossuth
OBrien ee 5
4¢
Bucte
‘
car
LG ° 5 ies
lda 3
+ reene| +- |e) ©
5 7 ae + :
+e Clinton
5 bY ° ei ones}
+ < Zes| Moi +? ~
2 . Keokuk npc
watid mie] . ES
a a . + .
.

Fig. 121-A. Distribution of Prostrate Spurge.

14

210 WEED FLORA OF IOWA
Snow-on-the-mountain (Huphorbia marginata Pursh.).

Description.—Stems stout, high, erect, hairy or smoothish ; annual,
from 2-3 ft. high; leaves sessile ovate-oblong, acute; uppermost
leaves white, petal-like margins.

The flowering spurge (Huphorbia corollata L.) with white flowers
in forked umbels; long peduncles; involucres showy, white append-
ages appearing like petals; deep perennial root; is common in gray-
elly and sandy soils in many parts of the state, and it is often weedy.

Distribution—Snow-on-the-mountain occurs from Minnesota to
Missouri and Colorado; also reported eastward to Ohio and South
Carolina. A frequent escape from gardens in Iowa; common only
in the western part.

Fig. 122. Snow-on-the-Mountain (Huphorbia marginata). A frequent escape

from gardens. a, Whole plant, one-third natural size; b, seed capsule,
natural size.

DESCRIPTIVE MANUAL 211

Fig. 123. Flowering Spurge (Huphorbia corollata). Common in sandy fields,
gravel Knolls, and roadsides.
(Drawing by Lois Pammel.)

Extermination.—This annual weed is easily exterminated by cul-
tivation. The young plant should be cut off below the surface of
the ground.

212 WEED FLORA OF IOWA
Cypress Spurge (Huphorbia cyparissias L.).

Description—Plant with perennial running root-stocks and
densely clustered stems from 6 in.-1 ft. high; linear, crowded leaves;
many-rayed umbel with glands crescent-shaped and granular pods.

Distribution.—Common westward from New England to Nebraska
usually in the vicinity of gardens and cemeteries.

Extermination.—This perennial weed because of its running root-
stocks is often difficult to exterminate. The ground should be given
a shallow plowing and the root-stocks exposed to the sun. It may
be necessary to repeat this process two or three times during the
summer. In addition to its propagation by the running root-stocks
it also propagates by its seeds.

Fig. 124. Cypress Spurge (Euphorbia cyparissias). Yellow ‘flowered’ plant
with milky juice and narrow leaves. Escaped from gardens to roadsides.
(Photographed by Colburn.)

DESCRIPTIVE MANUAL 213

>) NM =
SN

(Ce Sia

ate oe

z ee L is Perk - La
Se 9

PETELEBRRY

Fig. 124-A. “pisteanution of Cypress Spurge.

ANACARDIACEA®, SUMACH FAMILY.

Many of the plants are poisonous. “Many, like sumach, contain
tannin. Some, as the smoke tree, are cultivated for ornamental
purposes.

Poison Ivy (Rhus toxicodendron L.).

Description.—A climbing or trailing shrub sometimes erect, cling-
ing to trees or other objects by aerial rootlets; 3 leaflets ; inconspicu-
ous flowers; waxy fruit, frequently remaining on plant until late
winter or early spring. It is often mistaken for Virginia creeper
(Psedera quinquefolia (L.) Greene) which, however, has 5 leaflets.
Many persons are sensitive to poisoning from this plant, every part
of which contains the poisonous principle. The usual remedy for in-
fection from it is to wash the skin with a solution of sugar of lead.

Distribution.—Poison ivy is abundant throughout eastern North
America and the Rocky mountains. It is common everywhere in
Iowa, in hedge rows, thickets or woods.

Extermination —Poison ivy is not easily destroyed: because in
most cases it is troublesome in wood lots along fences and in yards.
It is difficult to destroy except by giving thorough cultivation. If
persistently cut off below the surface of the ground it can be de-
stroyed. Sodium arsenite at the rate of one and one-half to two
pounds to 52 gallons of water will help to destroy the weed. It is
not, however, safe to use this since it is a strong poison.

MALVACEAE, MALLOW FAMILY.
Cotton, hollyhock and okra are well known plants of the family.

214 WEED FLORA OF IOWA

Fig. 125. Poison Ivy (Rhus toxicodendron). Common in woods and along
fences. -
(Photographed by Colburn.)

Fig. 125-A. Distribution of Poison Ivy.-

DESCRIPTIVE MANUAL 215

Fig. 125-B. Poison Ivy (Rhus toxicodendron). a, spray showing rootlets;
; b, fruit. ;
(After Chesnut, U. S. Dept. Agr.)

Indian Mallow or Velvet-leaf, Butter-print (Abutilon theophrasti
Medice.).

Description.—A usually tall annual from 2-4 ft. high; plant with
strong odor; leaves velvety, roundish heart-shaped, taper-pointed ;
peduncles shorter than the petioles; corolla yellowish ; carpels 12-15,
hairy-beaked seeds rough, rather large and blackish.

Distribution.—Common in waste places, corn fields, vacant lots,
barnyards, ete. Common throughout eastern North America,
naturalized from tropical regions, probably India.

Extermination.—This plant propagates only by its seed, which
retains its vitality for some length of time, having been known to
germinate after a period of 60 years. The young plants are easily
exterminated. The plant should be pulled up before it begins to

216 WEED FLORA OF IOWA

Fig. 126. Indian Mallow, Velvet Leaf, or Butter-print (Abutilon theophrasti).
Common in carn fields, waste places, barnyards,
(Photographed by Colburn.)

flower. Wallace’s Farmer suggests the following treatment: ‘‘It
has been seriously thought of by some persons as a substitute for
manilla or sisal in the manufacture of binder twine. It is an an-
nual, and if not allowed to go to seed, the farm can in time be
cleared of it. But it will be a long time. The seeds have a most
astonishing vitality. We have known cases where it has been pulled
up for fifteen years, not a plant allowed to go to seed, and yet it
makes its appearance every spring. Fortunately, it grows only on
rich land, and is therefore found in evidence largely in hog yards
and feed lots and other places where the land is exceedingly rich.
In fact, in sections of the country where it is being introduced, it
may be found in almost every farmyard. Why farmers allow it to
mature seed passes our comprehension. It goes variously by the

DESCRIPTIVE MANUAL 217

Fig. 126-C. Pigweed, Foxtail, and Velvet Leaf, in a potato patch. Too many
such garden patches in Iowa.
(Photographed by Pammel.)

zoe
Ve =e
mAs = SEER

Fig. 126-B. Distribution of Indian Mallow.

218 WEED FLORA 'OF IOWA

names of velvet weed, butter print and in the locality of one of our
farms, Davis weed, from the fact that it was introduced many years
ago by a man named Davis, who regarded it as a rather good orna-
mental plant.’’

Sida (Sida spinosa L.).

Description.—An annual from 10-20 in. high; frequently much-
branched; leaves ovate-lanceolate; serrate with a long petiole, pe-
duncles in axils of leaves, 1-flowered; flowers small, yellow; 5 car-
pels, each 2-beaked.

Distribution—Common in the southern states, as far north as
Massachusetts to southern Iowa and Kansas.

Extermination.—This weed propagates entirely by its seeds which
retain their vitality for a considerable length of time, as the seed
coat is hard. The growing plant is, however, easily destroyed by
pulling the weed or by cultivation.

Fig. 127. Sida (Sida spinosa). Common in fields in southern Iowa.
(Photographed by Hart.)

DHSCRIPTIVH MANUAL 219

Fig. 127-A. Distribution of Sida.

Cheeses or Common Mallow (M alva rotundifolia L.).

Description.—A procumbent biennial ; leaves round, heart-shaped
on long petioles, crenate ; flowers white, petals longer than the calyx ;
a 3-leaved involucre at the base of the calyx; carpels pubescent.

Distribution.—A widely distributed weed in eastern North Amer-
ica, native to Europe, common in eastern and central Iowa in door-
yards, barn lots, etc., in Story, Marshall, Polk, Marion, Linn, Clin-
ton, Winneshiek and Allamakee counties.

Extermination.—This weed is easily exterminated by cultivation.
Do not permit any of the seeds to mature. The seeds retain their
vitality for a considerable length of time.

220 WEED FLORA OF IOWA

Fig. 127-B. Common Mallow or Cheeses (Malva rotundifolia). Common in door-
yards, barn lots, ete.
(Mich. Agr. Exp. Sta.)

DESCRIPTIVE MANUAL 221

Fig. 127-C. Distribution of Common Mallow.

Shoo-fly (Hibiscus trionum L.).

Description—A low, rather hairy annual from 1-2 ft. high ; upper
leaves 3-parted with 3 lanceolate divisions, the middle longest ; calyx
inflated in fruit, membranous, 5-winged, with numerous dark
nerves ; flowers sulphur-yellow with a blackish eye, ephemeral.

Distribution —Common in fields and waste grounds in the south-
ern states and eastward ; abundant in some places in Iowa, especially
in gardens where it has become naturalized from cultivation.

Extermination.—A. growing plant is not difficult to exterminate.
A thorough cultivation and exposing the roots to the sun will de-
stroy the plant. The seeds, however, retain their vitality for a con-
siderable length of time. A correspondent of southeastern Iowa
stated that this weed kept coming up in spite of constant and thor-
ough cultivation. This was owing to the prolonged vitality of the
seed.

HYPERICACEHAH, ST. JOHN’S-WORT FAMILY.

This small family contains a few ornamental plants with yellow
flowers, commonly found in northern states.

222 WEED FLORA OF IOWA

Fig. 127-D. Bladder Ketmia or Shoo-fly, (Hibiscus trionum). Gardens and
corn fields. Large white flower with a dark spot at the base of each petal.

a and b trichomes or plant hairs.
(a and b drawn by Charlotte M. King. The general aspect photographed by
Colburn. )

Fig. 127-E. Distribution of Shoo-fly.

DESCRIPTIVE MANUAL 223

St. John’s-wort (Hypericum perforatum L.).

Description.—A branched perennial, 114-2 ft. high with runners;
leaves elliptical, or linear-oblong, with pellucid dots; flowers
numerous in cymes, petals deep yellow, black-dotted, twice the
length of the lanceolate sepals.

Distribution.—Common in eastern North America in clay soils.
Abundant in Jowa only in eastern counties, especially northeast-
ward.

Extermination—This weed spreads both by seeds and by runners.
It is difficult to exterminate. Clark and Fletcher give the follow-
ing methods: ‘‘Close cutting several times during the summer will
reduce it in pastures. An application of salt—a small handful to

Fig. 128. St. John’s-wort (Hypericum perforatwm). Old fields and woodland
i pastures, eastern and northeastern Iowa.
(Photographed by Quade.)

224 WEED FLORA OF IOWA

y TRS

Fig. 128-A. Distribution of St. John's-wort.

each plant after close cutting in hot dry weather—will kill it and
may be practicable where the pest is not abundant and the land
cannot be brought under cultivation. Prevent it from going to seed.
St. John’s-wort is easily suppressed on land that cart be cultivated
under a systematic rotation of crops. Where it is established, it
would be well not to seed to grass until it is suppressed. ’’

ONAGRACEAE, EVENING PRIMROSE FAMILY.

A small family, some plants with showy flowers, a few cultivated
for ornamental purposes.

Evening Primrose (Oenothera biennis L.).

Description.—aA stout, erect, pubescent or hirsute perennial, 3-5
feet high, sparingly branched; leaves lanceolate, or rarely ovate-
lanceolate, denticulate, acute, bracts shorter or as long as the cap-
sule; flowers yellow, petals obovate, stigma lobes linear, capsule sub-
cylindrical; seeds small, brownish.

Distribution—Common everywhere in eastern North America,
Rocky mountains and Utah. Occurs in every county in Iowa.

Extermination.Spreads by seed. This plant is not difficult to
exterminate. Cut off the young plants a few inches below the sur-
face of the ground.

UMBELLIFERAE, CARROT FAMILY.

Carrot, celery, parsnips and caraway are members of this family.
Kt includes also many poisonous plants.

DESCRIPTIVE MANUAL 225

Tig. 129. Evening Primrose (Oenothera biennis). Fences, gardens, meadows
and pastures.
(Photographed by Hart. a, drawn by Charlotte M. King.)

\e tchell
2 .

Fig. 129-A. Distribution of Evening Primrose.

15

226 WEED FLORA OF IOWA
Caraway (Carum carvi L.).

Description—A smooth, erect, slender herb 1-214 feet high with
fusiform roots; leaves pinnate with filiform divisions; flowers in
umbels, white; calyx teeth small; fruit ovate, or oblong with fili-
form ribs.

Distribution—Common in eastern North America, the Rocky
mountains, Utah and scattered in places in Iowa.

Extermination.—Easily exterminated; cut off the plants below
the surface of the ground.

Fig. 130. Caraway (Carum carvi). Commonly escaped from gardens. Flowers
white.
(Photographed by Quade.)

DESCRIPTIVE MANUAL 227

Fig. 130-A. Distribution of Caraway.

Wild Carrot (Daucus carota L.).

Description.—A bristly, hirsute biennial from 2-214 feet high;
leaves pinnately decompound; involucral bracts foliaceous; flow-

Fig. 131. Wild Carrot (Daucus carota). Common in clover meadows. Flowers
in white umbels.
(Photographed by Colburn.)

228 WEED FLORA OF IOWA

Fig. 131-A. Distribution of Wild Carrot.

ers in compound umbels, white, or occasionally pink; fruit oblong,
flattened dorsally, carpel with 5 slender bristly primary ribs, and
4 winged secondary ones, each of these bearing a single row of
barbed prickles. canna ; 0 pean

' Distribution—Common in eastern North America, especially in
dry fields. Becoming common in Iowa clover fields in Scott, Story,
Polk, Franklin, Linn, Clinton, Cerro Gordo, Boone, Webster, Sac
and Clay counties.

Extermination.—Plant clean seed in a clean field. Easily killed
by cutting off the plant a few inches below the surface of the
eround.

Parsnip (Pastinaca sativa L.).

Description.—A tall, stout, glabrous biennial with grooved stem;
leaves pinnately compound, cut-toothed; flowers yellow, small;
calyx teeth obsolete; fruit oval, flattened dorsally, the lateral ribs
with broad wings.

Distribution—Common in eastern North America, Rocky moun-
tains and the Pacific coast.. Common on roadsides in every part of
Towa.

Extermination.—Propagated by seeds. Easily exterminated by
cultivation ; cut off the young plants a few inches below the surface
of the ground.

DESCRIPTIVE MANUAL ; 229

Fig. 132. Wild Parsnip (Pastinaca sativa). Common along roads.
(Mich. Agr, Exp. Sta.)

230 WEED FLORA OF IOWA

Fig. 132-A. Distribution of Wild Parsnip.

Cowbane (Cicuta maculata L.).

Description.—A smooth, marsh perennial, 2-5 ft. high, with pin-
nately compound leaves, 2 or 3 times pinnate; leaves with long
petioles; coarsely serrate leaflets lanceolate to oblong-lanceolate,
1-5 in. long; stalks of umbellets numerous and unequal; flowers
white; fruit broadly ovate to oval, small, 1144 in. long. The plant
grows in marshes and in low grounds, the stems springing from
thick fleshy underground roots tapering at the lower end, usually
numbering from 3-8 although single specimens are also met with.
On cutting the roots there is given off a sharp pungent odor, which
becomes intensified on boiling.

Distribution.—Common throughout the northern states, south-
west to Louisiana, Rocky mountains and Utah. Very common in
low grounds and swales in northern Jowa, less common in southern
Towa.

Extermination—The field where cowbane occurs needs drain-
age; plow the field, break.up the sod, and expose the fascicled
roots to the sun. This will soon destroy the weed.

DESCRIPTIVE MANUAL 231

Wig. 133. Cowbane (Cicuta maculata). In low moist meadows and roadsides.
(Photographed by Colburn.)

Fig. 133-A. Distribution of Cowbane.

23

Fig.

WEED FLORA OF IOWA

133-B. Cowbane (Cicuta maculata).
(Photographed by Caughey.)

In low woods.

DESCRIPTIVE MANUAL 233

Fig. 133-C. Cowbane roots (Cicuta maculata). In low places.

- (Photographed by Gardner.)

234 WEED FLORA OF IOWA

Cow Parsnip (Heracleum lanatum Michx.).

Description.—A stout, hairy, pubescent perennial 4-8 ft. high;

leaflets broad and large, irregularly cut-toothed; flowers white, in
broad umbels.

ig. 134. Cow Parsnip (Heraclewm lanatum). Common in woodland pastures.

. (Photographed by Charlotte M. King.)

Distribution—From the Atlantic coast, Newfoundland, through
the northern states and Allegheny mountains to California.
mon in the Rocky mountains.

Com-
APOCYNACEAE, DOGBANE FAMILY.

In the tropics several species are important rubber producing
‘
plants. They are commonly called milk-weeds in Iowa.

DESCRIPTIVE MANUAL 235

Spreading Dogbane (Apocynum androsaemifolium L.).

Description.—Root-stock horizontal, smooth, or rarely soft-tomen-
tose, branched above, spreading, leaves ovate, petioled, cymes loose, .
spreading, both terminal and axillary; the latter pale rose color,
open, bell-shaped; calyx segments shorter than the tubes of the
corolla.

Distribution—Common along borders of thickets from eastern
Canada to British Columbia to Arizona and Georgia. Abundant
in Iowa in grain fields near thickets.

Fig. 135. Distribution of Spreading Dogbane (Apocynum androsaemifolium).

Extermination.—Spreading dogbhane produces long, creeping
roots, which are quite tenacious of life. In order to destroy the
weed, the field should be given a shallow plowing after the grain is
harvested, followed by a disking in a week or ten days, depending
on the character of the weather. This should be followed by a
harrow. If the fall is dry dragging will probably get the larger
number of these weeds.

Indian Hemp (Apocynum cannabinum L.).

Description —Glabrous or more or less softly pubescent; 2-3 ft.
high, smooth, terminated by an erect, close, many-flowered cyme;
corolla lobes nearly erect, the tube not longer than the lanceolate
segments of the calyx, greenish white; appears in July and August.

Distribution.—Common species eastward and troublesome as a
weed in northern Mississippi valley. Common in small-grain fields
and pastures.

236 WEED FLORA OF IOWA

Figure 136 Figure 1364

Fig. 136. Indian Hemp (Apocynum cannabinum).

Fig. 136-A. Apocynum cannabinum hypericifolium. A low growing variety of
the above, but with leaves broader at base and more abruptly pointed
at apex.

(Schuyler Mathews in Mich. Agr. Exp. Sta. Bull.)

DESCRIPTIVE MANUAL 237

136-B. Distribution of Indian Hemp.

Extermination—This weed should be treated like spreading
dogbane.

ASCLEPIADACEAE, MILKWEED FAMILY.

A few plants, only, are of economic importance. Some are cul-
tivated for ornamental purposes. In Jowa they are commonly
ealled milkweeds.

Showy Milkweed (Asclepias speciosa Torr.).

Description.—A perennial 1-4 ft. high, white-tomentose or ca-
nescent; leaves thick, broadly ovate or oval, petioled; pedicel
elabrate above; flowers borne in dense umbels or rarely solitary,
the pedicels stout; corolla purplish green, large, follicle erect or
spreading on the recurved pedicels.

Distribution—Showy milkweed is common from Minnesota to
southern Iowa, Kansas, the Rocky mountains and Utah. In Iowa
it is abundant in Emmet, Palo Alto and Dickinson counties.

Extermination.—This weed should be treated like common milk-
weed.

238 WEED FLORA OF IOWA

Fig. 137. Showy Milkweed (Asclepias speciosa). In grain fields, meadows and
roadsides, northern Iowa.
(Photographed by Colburn.)

Fig. 137-A. Distribution of Showy Milkweed.

DESCRIPTIVE MANUAL 239
Milkweed (Asclepias syriaca L.).

Description—A perennial herb with a stout stalk 2-5 ft. high,
finely, softly pubescent or tomentose; leaves oblong, oval or ovate,
obtuse or roundish at the base, the young leaf somewhat pubescent
above, soon becoming glabrate; petioles stout, flowers from a few
to many, borne in umbels; peduncles pubescent or tomentose; co-
rolla dull purple or greenish purple, occasionally pale in color;
fruit a follicle and borne on erect pedicels; trichomes multicellular
from a single cell, somewhat floccose.

Distribution —This milkweed is common from New England to
North Carolina and Kansas. In Iowa it is abundant in oat fields,
on highways and in gardens throughout the state.

Fig. 1838. Common Milkweed (Asclepias syriaca). Fields, meadows, roadsides,
ete. a trichomes or plant hairs.
(Drawing by Charlotte M. King; general aspect photographed by Colburn.)

240 WEED FLORA OF IOWA

jaa INaeeal
4 \ +, z eles [ee MaeMN. | + ‘
Kossuth » ee *
fore hE a ae || tae :
. . . ens .
5 . beni) OSE

ee Fa serey
antl reene| ore ® a

+ ss

Sea ies
7 | ? FE L ‘ ‘ \oaes| Morbes
Be ciali, | elas
ye °

> aR OE

LY ezell| T>0ni| So Wesabe
e: hea | :

{eel S SLE | Salaam

Fig. 138-A. Distribution of Common Milkweed.

Extermination.—Both milkweeds have the same habit of growth.
The weed is perhaps known by its long roots which are frequently
10-15 ft. in length; another important point is that it produces ad-
ventitious buds at frequent intervals from which new shoots arise.

Fig. 138-B. Common Milkweed (Asclepias syriaca). Grain fields, waste places.
(Photographed by Charlotte M. King.)

DESCRIPTIVE .MANUAL 241

Wallace’s Farmer says concerning this weed: ‘‘We would ad-
vise our correspondent to plow this field as scon as_ possible
and prepare his seed bed for winter wheat. By plowing it again
next August he will undoubtedly weaken the stand. He will
fail, however, unless in working his corn he uses surface cultiva-
tion. These weeds have no doubt been distributed through the
field during the three years it was in corn by using a shovel cul-
tivator, which takes up the roots and carries them over the field
in the same way that many northern farmers are now seeding their
fields with quack grass and damaging them to the extent of from
five to twenty dollars per acre. By giving these two thorough
August plowings and taking care of the roots that may be thrown
up, then preparing the seed bed very thoroughly for corn and
giving it as far as practical surface cultivation, he will probably
get rid of these noxious weeds.’’

Climbing Milkweed (Gonolobus laevis Michx.).

Description.—A climbing perennial; leaves oblong, cordate with
a deep, narrow sinus; flowers borne in axillary umbel-like cymes,
5-10 flowered, large greenish flowers; calyx 5-parted; corolla 5-
parted, wheel-shaped, the lobes narrowly linear-lanceolate, obtuse,
larger than the calyx; anthers horizontal under the flattened
stigmas ; pollen masses 5 pairs, follicles with soft warty projections.

Distribution.—Troublesome in woods and fields in the southern
states. It is reported as troublesome from a few counties in south-
ern Iowa.

Extermination.—This perennial weed is as difficult to destroy as
common milkweed. Give thorough cultivation. If this will not suf-
fice get the field into a meadow.

CONVOLVULACEAE, MORNING-GLORY FAMILY.

Few economic plants. Sweet potato and cultivated morning glory
are representatives.

16

242

Pig.

WEED FLORA OF IOWA

139.

Climbing Milkweed (Gonolobus laevis).
southern Iowa.
(Drawing by Ada Hayden.)

Troublesome in fields in

DESCRIPTIVE MANUAL 243

rere] S

y Bren iS Masset a N
yi ES \ Baer \ ae
h
Wy phim oy 1] i S x ee AC

IN {|

Fig. 139-A. Distribution of Climbing Milkweed.

Morning-glory (Ipomoea hederacea Jacq.).

Description— Stems retrorsely hairy; leaves heart-shaped,
3-lobed, the lobes usually acute; peduncle variable in length; 1-3

Fig. 140. Blue Field Morning-glory (Ipomoea hederacea). Fields, common
southern Iowa and Missouri.
(Photographed by Colburn.)

244 WEED FLORA OF IOWA

FSI DSRS
EPR

Fig. 140-A. Distribution of Morning-glory.

flowers; calyx densely hairy below; corolla funnel-form, white and
purple or pale blue; lobes of stigma and cells 3.

Fig. 141. Annual Morning-glory (Ipomoea purpurea). A frequent escape from
gardens into fields,
(Photographed by Colburn.)

DESCRIPTIVE MANUAL 245»

Fig. 141-A. Distribution of Annual Morning-glory.

The I. purpurea has heart-shaped leaves with retrorsely hairy
stem; peduncles long, umbellately 3-5 flowered, purple to white.

Distribution.—Common in waste and cultivated grounds from:
New England southwestward; abundant from Missouri southward;
native from tropical America; rare in Iowa. The J. purpurea is.
commonly cultivated and is a frequent escape from cultivation in.
Hardin, Story, Marshall, Wapello and Marion counties.

Extermination—It is an annual and is easily destroyed; how-
ever, the seeds retain their vitality for some time, frequently
springing up for several seasons after the most thorough ecultiva-
tion. )

Hedge Bindweed or Morning-glory (Convolvulus sepium L.).

Description—Smooth, occasionally, however, pubescent, twining
around supports or trailing; leaves triangular, halberd or arrow
shaped, the tip acute, or pointed, the basal lobes obliquely trun-
cate or sinuate lobed; flowering peduncles 4-angled with 2 leaf-like
bracts which are commonly acute; corolla white or tinged with
rose purple.

DistributionHedge bindweed or morning-glory is common in
the northern states and in the southwest from Texas to Canada,
also in the Great Basin country. A form of it is also found in
Europe and Asia. Common in every section of Iowa not only in
corn fields, but along highways and in small-grain fields.

246 WEED FLORA OF IOWA

Fig. 142. Morning-glory (Convolvulus sepiwm). Common in grain, corn fields
and meadows.
(Photographed by Colburn.)

Fig. 142-A. Distribution of Hedge Bindweed or Morning-glory.

DESCRIPTIVE MANUAL 247

Extermination —The morning-glory must be treated like horse

nettle since it is a perennial. In addition to the usual methods of
cultivation sheep have been recommended to destroy the weed.

This method is certainly applicable where the weed occurs in pas-
tures.

In Wallace’s Farmer, Mr. L. C. Greene’s experience in killing
morning-glory is given as follows: ‘‘A large farmer had 145 acres
of corn. One piece of twenty acres, fall plowed, on a south slope,
was planted to corn the first of May, and by the time the plowing
and planting were all done it was near the last of May. The early
planted field was thick with-morning-glories and had received no
cultivation since they commenced to grow. By the time the corn
was four inches high the morning-glories were eight or more inches
tall, growing in mats on the ground hunting for something to climb
upon. The proprietor viewed the field, and instead of sending out
the cultivator sent out three stirring plows and the planter soon
followed. In two days the field was plowed and planted again and
a fine crop of corn was raised with very little bother from the vines,
and even the following year the vines bothered but little.

‘‘Some years ago I fall plowed a small field that was badly in-
fected with morning-glory vines and smartweeds. The 24th of the
next May I was ready for that field, but from a little distance it
looked as if a mowing machine and a rake would be the proper tools
to use. I plowed rather deep to do a good job, the planter im-
mediately followed, and in four days after the planter some corn
could be seen, and it was eight inches high when the cultivator
got to it. It was just a matter of stirring the soil all season, for
there were no large weeds to kill.’’

The Prairie Farmer makes these suggestions concerning the
eradication of morning-glory: ‘‘ Another way to fight the morning-
glory is to grow two or three pasture crops a year on the land for
sheep. One of them ought to be a cultivated crop. The morning-
elory would not be able to hold out long against such treatment.
The strong point in favor of this method is the profitable character
of the work.’’

Wallace’s Farmer says concerning its destruction: “‘They do
not spread rapidly except under cultivation, as they grow
mostly from the roots, and these are distributed over the fields:
by cultivators. If when the farmer first discovers a patch out of
cultivation for a year or two he plows it shallow and frequently

248 WEED FLORA OF IOWA

and harrows he can get rid of them. If he cultivates the plants
with the rest of his field it is only a short’ time until he will find
these weeds scattered all over his field. A great many ways have
been suggested to get rid of this troublesome weed. Special at-
tachments have been invented for the use on corn cultivators
known as the morning-glory blades. These are designed to shave
off the plants just below the surface of the ground.”’

‘“We certainly would fence up this pasture, or part of it, and

would sow a mixture of grains that would furnish hog feed, and LA

while we were at it would sow clover and timothy, and when the
grains were three or four inches high turn in the hogs. The only
trouble is that there are not enough hogs to go around the whole
tract. We had a field in that condition twenty years ago. We
made a hog pasture of it, and while the morning-glories are yet

to be seen in the road alongside, there are none of them in the

f ,

pasture, and have not been since the first year.”’

European Bindweed or Morning-glory (Convolvulus arvensis L.)

Description.—The European bindweed or morning-glory is a
deep-rooting perennial; stem procumbent, twining or creeping.
Like the horse nettle, this species propagates freely by under-
ground root-stocks; leaves 1-2 in. long, ovate, oblong, arrow-shaped,
lobes at the base running to a point; flowers borne in 1-flowered
peduncles with very small leaf-like bracts some distance from the
flowers; flowers an inch or less long, short, broadly funnel-shaped,
white or commonly of a rose tinge.

Distribution.—European bindweed is a troublesome weed in Eur-
ope and in eastern North America. It occurs also in the southern
states and on the Pacific coast. It is scattered in many parts of
Towa in small patches.

Extermination.—A short rotation of crops should be practiced,
including late sown roots or other cultivated crops: rape is useful
for this purpose. Frequent use of a broad-shared cultivator will
destroy new growths and exhaust the vitality of the plants. Sow
no crop seeds containing those of field bindweed. Applications of
salt or lime, sometimes recommended to kill this weed, are useless
unless appled in large quantities.

SS

DESCRIPTIVE MANUAL 249

ra

mae
>
a
\

Fig. 143. European Morning-glory or Bindweed (Convolvulus arvensis). Com-
mon in gardens and becoming frequent in Iowa.
(Photographed by Colburn.)

Fig. 143-A. Distribution of European Morning-glory.

250 WEED FLORA OF IOWA

Prof. H. A. Hitchcock in Farmer’s Review, says: ‘‘The black
bind-weed or perennial morning-glory (Convolvulus arvensis),
which I suppose is the kind meant, is a great pest and difficult to
eradicate. If a patch is not too large, heavy mulching is the best
way to destroy it. Then watch the patch closely and eut off im-
mediately any stray shoot that may appear above its surface.
Nothing but persistent watching and the careful cutting off of
all parts above the ground will eradicate this weed.’’

Prof. Ten Eyck, quoted in Wallaces’ Farmer, states that the only
method of culture applicable to large areas which promises any
great degree of control or destruction of the pest is very late fall or
winter plowing. The plots which were plowed in November (no
plowing was done later than November 20th) showed a very scat-
tering and feeble growth of bindweed on April 26th, the date of
inspection.

The weeds were thinner and more feeble also on the unplowed
land which produced a crop of sowed cane or sowed kaffir last
season, than they were on any of the lots cultivated in intertilled
crops.

Clover Dodder (Cuscuta epithymum Murr.).

Description.—A spreading, climbing plant; yellowish or reddish
with a few minute scales in place of leaves; flowers whitish or pink-
ish in heads, small, globular, urn-shaped; cylindrical tube longer
than the nearly erect, acute sepals; scales large-toothed; stigma
elongated; style longer than the ovary; stamens exserted, fruit in
capsules.

Distribution—This weed has long been known as troublesome
in Europe and has been more or less common in the Rocky moun-
tains on clover and alfalfa. For some years also frequent in the
east; becoming more abundant on clover and alfalfa.

Extermination—Where the plant occurs cut down the clover at
once and burn. Sow the patch or field to another crop, preferably
to small grain or with corn.

Clark and Fletcher recommend the following treatment: ‘‘As
soon as the pest is noticed, the infected patches should be at once
mown with a scythe and the refuse removed and destroyed. Fields

DESCRIPTIVE MANUAL 251

Fig. 144. Clover Dodder (Cuscuta epithymum). <A yellow twining plant on
clover and alfalfa.
(Photographed by Colburn.)

Fig. 144-A. Distribution ‘of Clover Dodder.

badly contaminated should be plowed before the seed has formed,
or the crop cut early for hay and the land then plowed. Clover
seed should never be taken from fields infested with this pest.’’

The Wisconsin Farmer states: ‘‘The problem of dodder control
is strongly influenced by the character of the crop infested. Red
clover remains but two, or at most but three, years without re-
seeding. If the dodder is prevented from seeding it should be
eradicated within this time, or at least not interfere with the
-eourse of crop rotation. Alfalfa should remain indefinitely, and

252 WEED FLORA OF IOWA

if dodder reseeds itself its control becomes much more difficult or
impossible. This is the prevailing condition in the west. The fact
that the small-seeded alfalfa dodder of the west has not become
established in the east is of special interest in this connection.
Clover dodder appears likely to prove the most troublesome in
alfalfa culture in the east.

‘‘Tf the dodder occurs only in patches in the field it usually can
be controlled by hand methods. If it covers the greater part or all
of the field, plowing under the stand will probably be found nec-
essary. It then becomes important to know how far the crop can
be utilized without reseeding the land to dodder.’’

Field Dodder (Cuscuta arvensis Beyrich.).

Description—Stems pale and slender, filiform; flowers rather
small, in sessile clusters; calyx with 5 obtuse broad lobes; corolla
with a short, wide tube, inflexed points, 5-lobed, acute or acumi-
nate, about 14 as lone as the tube, tips reflexed; scales large and
deeply fringed; stigmas capitate; capsules globose, indehiscent.
Occurs on shrubs, clover and other herbs.

Distribution.—Massachusetts to Wisconsin and westward. In-
troduced with clover and alfalfa seed in Jowa.

Extermination—The dodders are largely spread through com-
mercial seeds, like flax, clover and alfalfa. Alfalfa dodder is a
somewhat troublesome weed in sections of the United States and
Europe where alfalfa is grown; in this way it has made its way
into the Mississippi valley in recent years. There has been much
complaint about the appearance of clover and field dodder in the
same region, largely spread, of course, through commercial seeds.
The dodder may be exterminated in the following way:

First by the herbicidal treatment. For this purpose a liberal
application of a 10 per cent solution of copper sulphate will be
found efficacious.

In addition, the European investigators recommend a strong sol-
ution of salt, sulphide of lime, carbolic acid, and sulphate of iron.
These solutions will destroy the dodder when found in the vegeta-
tive condition, but should seed occur, then it will be necessary to
take the additional precaution of cutting the dodder after the ap-
plication of the herbicide and burning it. It should be remembered
that these solutions will not be effective unless they come in direct ~
contact with the plant. They will injure the clover plant as well.

DESCRIPTIVE MANUAL 253

‘+ 4%
a: 4

Figure 145 Figure 145A Figure 145B

Fig. 145. Field Dodder (Cuscuta arvensis).
Fig. 145-A. Flax Dodder (Cuscuta epilinum).
Fig. 145-B. Lesser Clover Dodder, Thyme Dodder (Cuscuta epithymum).

254 WEED FLORA OF IOWA

Wig. 145-C. Distribution of Field Dodder.

It is advisable to mow the patch if it is a small one, to rake the
material into a pile, and after allowing it to dry to burn it. The.
field should be watched carefully, for if the seed is formed, young
dodder plants will make their appearance upon the new growth of
clover. It 1s best therefore to follow the mowing by hoeing if the
spot is a small one and continuing this for several weeks until all
danger of infection is passed. Dewey recommends keeping the soil
stirred for about two inches and not allowing any young plants to
come in contact with the clover.

Wallace’s Farmer suggests the following treatment: ‘‘ Where
our readers find this yellow vine twining around their clover or al-
falfa they must act promptly and effectively. If when they dis-
cover dodder they will cut it off close to the ground before it seeds
no damage will follow, as dodder is an annual. It will not do, how-
ever, to trust to the scythe or mower, for the least particle of dod-
der which remains attached to the stubble will grow much more
certainly than any corn or wheat will grow. Where a whole field ©
is infested perhaps the safest way is to mow it before the dodder
goes to seeding, use it for hay, and then plow it up for a erop the
next year. Or, if we would rather lose a crop of hay than lose the
stand, mow it, let it dry, and burn it, so as to destroy the dodder
in the stubble.’’

HYDROPHYLLACEAH, WATERLEAF FAMILY. |

The common waterleaf belongs to this family. Representatives
of the family are more numerous in the west and south than in the
east and north.

DESCRIPTIVE MANUAL 255

Common Ellisia (Ellisia nyctelea L.).

- Description.—Minutely or sparingly roughish hairy; stems
forked, 6-14 in. high; leaves pinnately parted into 7-13 sparingly
cut-toothed divisions; peduncles 1-flowered, opposite the leaves;
flowers with calyx lobes lanceolate; pointed corolla white.

Fig. 146. Ellisia (Hllisia nyctelea). Common in early spring fields.
(Photographed by Colburn.) ates

Fig. 146-A. Distribution of Ellisia.

256 WEED FLORA OF IOWA

Distribution—Common in shady and damp places everywhere in
Iowa and a weed in cultivated fields. It is distributed from New
Jersey to Kansas, and in the northwest territory.

Extermination.—This is a spring weed of waste, shady places.
Sow thickly with some leguminous crop, like clover, or get blue
grass started. The weed is easily destroyed by cultivation.

BORAGINACEAE, BORAGE FAMILY.

Comfrey, bugloss, alkanet, blueweed and borage belong to this
family. Many of the plants are scattered by animals because of
the burs.

Hound’s Tongue (Cynoglossum officinale L.).

Description—A coarse biennial herb, clothed with short, soft
hairs; lower leaves oblong or oblong-lanceolate, the upper closely
sessile with a slightly heart-shaped base; racemes nearly bractless,
elongated in fruit; divisions of the calyx ovate, lanceolate, acute;
corolla reddish purple, rarely white; nutlets flat on the broad up-
per face, splitting away at maturity.

Distribution.—In fields and waste places, especially westward
from New England to Quebec, Ontario, Minnesota, Manitoba and
Kansas.

Extermination.—This weed should be cut a few inches below the
surface of the ground. It is easily killed. The ‘‘seeds’’ are, how-
ever, widely scattered by animals; stray plants should be looked
for.

257:

DESCRIPTIVE MANUAL

The burs

In pastures.

Hound’s Tongue: (Cynoglossum officinale).
are scattered by ‘sheep.

Fig. 147.
(Photographed by Colburn.)

le,

Keokuk preset

Fig. 147-A. Distribution of Hound’s Tongue.

258 WEED FLORA OF IOWA
Wild Comfrey (Cynoglossum virgimanum L.).

Description.—Perennial hirsute herb with simple stem 2-3 ft.
high, leafless above; stem leaves lanceolate-oblong, clasping by a

heart-shaped base; flowers on long peduncles, pale blue, small; fruit
broad, nutlets not margined, convex on the upper surface.

Distribution.—Common in woods of the central Mississippi val-
ley, New Brunswick to Ontario, Florida, Louisiana to Texas. Com-

mon in eastern to central Iowa near woods.
Extermination—Sometimes persistent in newly made fields in
the northern states. Cultivation for a few seasons will remove the

weed.

Woodland pastures.

Wild Comfrey (Cynoglossum | virginianum).
(Photographed by Colburn.)

Fig. 148.

DESCRIPTIVE MANUAL 259

Fig. 148-A. Distribution of Wild ‘Comfrey.

Beggar’s Lice (Lappula virginiana L.).

Description—aA coarse, pubescent biennial 2-4 ft. high; lower
leaves ovate, orbicular, cordate, long-petioled; stem leaves ovate-

Fig. 149. Beggar’s Lice (Laprula virginiana). Common in woodland pastures.
(Photographed by Colburn.) Pi

260 WEED FLORA OF IOWA

oblong or oval; flowers nearly white; globose nutlets which are
flattened and barbed on the back.

Distribution—Common especially in woods northward, from
New Brunswick to Wisconsin and Minnesota, also from Kansas to
Louisiana. Common on borders of woods and in wooded pastures
in Iowa.

Extermination.—Cut the plant the first season a few inches be-
low the surface of the ground. When the plants shoot up the sec-
ond season give the same treatment. The plants are disseminated
by animals. Stray plants along fences should be looked for and
destroyed.

Stickseed (Lappula echinata Gilibert).

Description.—An erect annual 1-2 ft. high; pale, leafy, hispid
with erect branches; leaves linear or linear-oblong; racemes
1-sided; bracteolate; calyx segments lanceolate; corolla blue; nut-
lets rough-granulate or tuberculate on the back, the margins with
a double row of slender prickles.

Distributton—Abundant in waste places along roadsides from
eastern Canada and New England to Minnesota, Kansas and Brit- -
ish Columbia. Weedy in Europe, where it is native. Common
along roadsides and gravelly places in eastern Iowa.

Extermination—Destroy the plant before the seeds form, by
cutting off below the surface of the ground.

DESCRIPTIVE MANUAL 261

Fig. 150. Stickseed. Bur Seed (Lappula echinata). Along roadsides.
(From Mich. Agr. Coll. Exp. Sta. Bull.)

262 WEED FLORA OF IOWA

Fig. 150-A. Distribution of Stickseed.

Corn Gromwell (Lithospermum arvense L.).

Description—A pubescent annual with stems 6-12 in. high,
with bright green, lanceolate, linear, or oblong, sessile leaves ;

Fig. 151. Corn Gromwell or Puecoon (Lithospermum arvense). A common
roadside and field weed of Hurope. Southern Iowa and Missouri. Small
white flowers.

(Photographed by Colburn.)

DESCRIPTIVE MANUAL 263

flowers sessile or nearly so, white; calyx segments longer than the
corolla tube; corolla funnel-form; nutlets smooth.
Distribution.—Common weed in fields in the east; may be looked
for in southeastern Iowa. One of the most common weeds in grain
fields in Europe.
Extermination.—The plants are easily destroyed. The seeds
probably retain their vitality for some time as the coat is hard.

VERBENACEAE, VERBENA FAMILY.

The common cultivated verbena and lemon verbena belong to
this family.

Blue Vervain (Verbena hastata L.).

Description.—A tall perennial 4-6 ft. high; leaves lanceolate,
coming to a point, cut-serrate, lower leaves often lobed; flowers in
erect, linear, corymbed spikes, violet-blue or rarely pink; trichomes
simple, long, acuminate.

4

aA ky
AM

Fig. 152. Vervain (Verbena hastata). Common in low pastures and meadows.
a Trichome.
(Photographed by Quade. a drawn by Charlotte M. King.)

264 } WEED FLORA OF IOWA

Pr LAL [pk RAE

aA) Re ae
CELE cee
2

8

aia AS = 3

faaaaaee

Fig. 152-A. Distribution of Vervain.

Distribution.—In damp situations in every county in the state of
Towa; also to the Atlantic coast and westward and southward.

Extermination —This weed, though abundant in low grounds,
seldom gives trouble where the field is drained and thorough eulti-
vation is given. Spreads chiefly by the seed.

Hoary Vervain (Verbena stricta Vent.).

Description.—A soft, pubescent, perennial 1-3 ft. high; leaves
downy, ovate or oblong, serrate and sessile ; large blue flowers borne
in a dense sessile spike, 6 in.-1 ft. long; trichomes several-celled,
thick-walled, pitted.

The white vervain (V. urticaefolia) grows much taller than
V. stricta and has very small white flowers on elongated spikes.
It is a weed of thickets and waste grounds.

Distribution—In dry soil, prairies of Ohio to South Daktoa and
Wyoming, New Mexico and Texas. - Commonly naturalized east-
ward. A common weed in every part of Iowa; frequent in pas-
tures.

Extermination.—Kasily destroyed by cultivation; rarely found
in cultivated fields for that reason.

DESCRIPTIVE

MANUAL

Fig. 153. Hoary Vervain (Verbena stricta). Common in pastures. Plant with

blue flowers.

(General aspect photographed by Colburn.

Plant hair, trichome, to the right.

: e "2. a oz Sar AY acces cal (peel (ee
oT [ENT TY et |] >. S49 dt Ea eo
; ; Kossuth = ~ state C
© OBrien ; : Sees 50
° ary eee 0, 2 ° “4 ely * fe 0
+ °
. . i) +H * |e s + 04
Loy AUS; SAIRSSSI o wll *,\ 728k | *
PS s L
sige ly A. Solo lol eae 5 ‘ SG * qubuque
+ "af e Ma, a ae a . . t 2. : e
OOO 2g rene Pies ° : 4
Gt foe fl oP te | AP Remedy oe | 6 iy [
e| ¢ irs . > > 2
= = . © Clinton
+ + he °
. ° ry ° onsen °
te s ° 0 © \oces| Motes © e? .
5 Tataranine|
‘ ave : “|eokuk | 5
wattdrne) 7 ¢ * ‘ee e ‘ : 5
5 . ° . A A
. 5 °
, . ° 0

Fig. 153-A. Distribution of Hoary Vervain.

a, drawn by Charlotte M. King.)

266 WEED FLORA OF IOWA

AA SESS

sani

Fig. 153-B. White Vervain, Nettle-leaved Vervain (Verbena urticaefolia).
(Mich. Agr. Exp. Sta.)

DESCRIPTIVE MANUAL 267.

taba Ee.

Cue hey

Fig. 153-C. Distribution of White Vervain.

Common Vervain (Verbena bracteosa Michx.).

Description.—A widely spreading, hairy annual; leaves wedge-
lanceolate, cut-pinnatifid or sometimes 3-cleft; flowers in spikes,

i
‘ oe

d

‘ :
7
2 os
EES
ee
i

Fig. 154. Prostrate Vervain (Verbena bracteosa). a, Plant hair or trichome.
Common along roadsides, streets, and gravelly places; small, blue flowers, —
(General aspect photographed by Quade. a drawn by Charlotte M. King.)

268 WEED FLORA OF IOWA

Basse et
Hit bets Bee oe:
ee GRE

PSSese

AREER
C/A are:

Fig. 154-A. Distribution of Prostrate Vervain.

with large bracts, small, purple; trichomes few-celled from a broad
several-celled base.

Distribution.Common in waste places, roadsides, walks, gravel-
ly and sandy fields from Virginia to Wisconsin and Minnesota and
southward.

Eaxtermination.—It is easily exterminated by cultivation.

LABIATAE, MINT FAMILY.

The common pepperment, scarlet sage, catnip, pennyroyal, thyme
and basil belong to this family. All are aromatic plants.

Mint (Mentha arvensis L.)..

Description.—This perennial weed has freely branching stems
1-114 ft. high, retrorsely pubescent, leaves oblong to ovate, rounded
at the base, minutely pubescent, closely serrate, petioled or nearly
sessile; flowers white, pink or violet. The varity canadensis has
lanceolate to oblong-lanceolate, pubescent leaves and is the common
form in Iowa in low grounds. Several other species occur in Iowa,
namely: peppermint (Mentha piperita) along brooks, a smooth
and pungent-tasting herb with ovate-oblong leaves and running
root-stocks, and spearmint (Mentha spicata) with oblong or ovate-
lanceolate unequally-serrate leaves.

Distribution.—This Eurasian species occurs from Newfoundland
to Nebraska and the Pacific coast.

Extermination.—Easily exterminated by giving thorough culti-
vation and dragging the soil to bring the root-stocks to the surface
of the ground.

DESCRIPTIVE MANUAL - 269

Fig. 155. Mint (Mentha arvensis var. canadensis). Common in low meadows;
whitish flowers. Plant with odor of peppermint.
(Photographed by Colburn.)

Fig. 155-A. Distribution of Mint.

270 WEED FLORA OF IOWA

Fig. 155-B. Peppermint (Mentha piperita). In some gardens,
(Photographed by Colburn.)

Carpenter Weed, Self-heal (Prunella vulgaris L.).

Description.—A low, perennial weed with ovate-oblong, entire or
toothed leaves, hairy or smooth; flowers collected in heads of
3-flowered clusters, corolla violet or flesh-color, or rarely pale in
color, longer than the purplish calyx which is tubular bell-shaped.

Distribution—Widely distributed in northern United States,
west across the continent in clay soils and woods, also from New-
foundland to Florida.

Extermination—This weed is not difficult to exterminate by
giving cultivation with a cultivator and hoe. The weed is mainly
spread by seed. The seed of this is not uncommon in clover seed.

DESCRIPTIVE MANUAL 271

Fig. 156. Self-heal (Prunella vulgaris). Common along roadsides, wooded
pastures.
(Photographed by Quade.)

Fig. 156-A. Distribution of Self-heal. ae id

272 WEED FLORA OF IOWA

American Germander (Teucrium canadense L.).

Description —A_ perennial, downy, erect herb 1-3 ft. high with
running root-stocks; leaves pubescent, short-petioled, downy be-
neath, ovate, lanceolate, serrate with a rounded base; floral leaves
small; flowers in ample wandlike spikes; calyx 5-toothed, the up-
per lobes obtuse; corolla purple, rose or whitish.

Distribution—From New England to Mexico and northwest to
Manitoba. Common in Iowa alluvial grounds in pastures, mead-
ows, grain fields, ete.

Extermination.—A very troublesome weed in the north. It is,
however, an excellent bee-plant. Should have the same treatment
as quack grass. The root-stocks should be exposed and allowed to
dry. After plowing the field follow with a dise and harrow once
a week after the small grain crop is removed.

Fig. 157. Germander or Wood Sage (Teuchriwmn canadense). Common in fields
and woods.
(Photographed by Colburn.)

DESCRIPTIVE MANUAL 273

Fig. 157-A. Distribution of Germander.

L. H. Pammel in the Weekly Register says: ‘‘Germander is a
troublesome weed found in many parts of northern Iowa. It pro-
duces root-stock very much like mint and quack grass. Each sev-
ered portion produces a new plant, and for this reason it is some-
what difficult to destroy. The only way to exterminate this weed
is by thorough cultivation. Plowing in the fall during the dry
season, then plowing again in the spring and giving thorough cul-
tivation during the growing season should destroy the weed with-
out difficulty.’’

Catnip (Nepeta cataria L.).

Description.—A perennial, erect herb, 1-3 ft. high; leaves ovate,
cordate, coarsely serrate, petiolate, whitish, downy underneath;
flowers in cymose clusters; corolla whitish, dotted with purple;
trichomes several-celled, rough, thick-walled.

Distribution—Native to Europe; widely naturalized in the
northern states.

Extermination.—Give the same treatment as to motherwort.

Chemical Composition.—According to the University of Min-
nesota*, it is as follows :—

k Nitrogen free
Dry Matter Crude Protein Ether Extract Extract and Ash
Fiber
94.30 22.25 | 2.66 | 63.07 12.77

*Snyder: Bull. Univ. Minn. Agr. Exp., 101.
18

274 WEED FIORA OF IOWA

Fig. 158. Catnip (Nepeta cataria). Trichome or plant hair at the right. Com-
mon in waste places.
(Photographed by Colburn. Drawing of hair by Charlotte M. King.)

+ Jared \
. 4 AUS

Figure 158A Figure 158B

Fig. 158-A. Plant hair or trichome from leaf of catnip.
(Drawing by Charlotte M. King.)

Fig. 158-B. Distribution of Catnip.

DESCRIPTIVE MANUAL 275
Ground Ivy (Nepeta hederacea (L.) Trevisan).

Description.—A creeping, trailing perennial, with leaves all
alike, petioled, round, kidney-shaped; crenate, smooth, green on
both sides; flowers light blue in axillary whorls of about 6, ap-
pearing in early spring and summer.

Distribution.—Native to Europe, widely naturalized in the
northern states, especially in shady places. Common everywhere
in Jowa.

Extermination—Somewhat difficult to exterminate in lawns,
but thorough cultivation will destroy the weed.

Fig. 159. Ground Ivy or Creeping Charley (Nepeta hederacea). Common in
some gardens.
(Photographed by Colburn.)

276 WEED FLORA OF IOWA

eee
si

Fig. 159-A. Distribution of Ground Ivy.

Motherwort (Leonurus cardiaca L.).

Description.—Tall perennial herb with erect stem, 2-6 ft. high;
leaves long-pointed, the lower round and palmately lobed, the up-

ig 160. Motherwort (Leonurus cardiaca). A common weed in waste places
and gardens.
(Photographed by Colburn.)

DESCRIPTIVE MANUAL 277

eee

Fig. 160-A. Distribution of Motherwort.

per crenate at the base, 3-cleft; flowers pale purple, in close axil-
lary whorls; corolla bearded.

Distribution.—Native to Europe, widely naturalized in the north-
ern States.

Extermmation.—This perennial weed can be exterminated by
plowing the field with frequent cultivation subsequently.

Blue Sage (Salvia lanceaefolia Poir.).

Description—A_ slightly pubescent or nearly smooth annual,
1-214 ft. high; leaves petiolate, lanceolate serrate or nearly entire;
flowers in interrupted, erect spikelike clusters; calyx bilabiate,
upper entire, the lower 2-cleft; corolla, blue, slightly exserted;
stamens with long connective, attached to a sterile anther which
blocks the throat of the corolla; pistil 1, deeply 4-lobed. Plant
related to the cultivated garden salvias.

Distribution.—Chiefly west of Missouri river, Kansas, Nebraska,
Texas, and Arizona, Missouri and Indiana, introduced in Ohio.
Common in Pottawattamie, Fremont, Monona and Woodbury coun-
ties, less common in Story, Boone, Polk and Muscatine counties.

Extermination—tThis weed is easily exterminated by cultivation.
Do not allow the plant to produce seeds.

SOLANACEAE, NIGHTSHADE FAMILY.

Potato, tomato, tobacco, ground cherry, jimson weed, flowering
tobacco and black henbane, belong to this family.

278

WEED FLORA OF IOWA

Fic. 161. Lance-leaved Salvia, Blue Sage (Salvia lanceaefohe).

DESCRIPTIVE MANUAL 279

Wig. 161-A. Distribution of Lance-leaved Salvia.

Ground Cherry (Physalis lanceolata Michx.).

Description —aA hirsute perennial with short, stiff hairs, some-
times nearly smooth; forms short and stout underground stems;
leaves oblong-ovate to lanceolate, sparingly angulate-toothed or
more often entire; flowers in axillary peduncles, calyx hirsute, co-
rolla yellowish with a dark eye; berry reddish. The P. virginiana
Mill., is also an erect perennial with narrowly ovate acutish leaves
or acutish or rounded teeth, corolla pale yellow. The P. subglab-
rata MacKenzie and Bush, has ovate or ovate-oblong leaves, oblique
at the base, entire or repand, and brownish corolla; berry, large,
reddish or purple. The P. heterophylla is perennial, leaves obtuse
repand, or obtusely toothed; trichomes several-celled, glandular
and non-glandular.

Distribution—The P. lanceolata in southern Iowa and south-
ward, the P. virginiana common everywhere in Iowa, in dry grav-
elly soil, from Connecticut to Jowa and southward; the P. sub-
glabrata from Rhode Island to Minnesota and southward.

Extermination —All of the perennial ground cherries are diffi-
cult to destroy because of the strong underground root-stocks which
freely spread the weed. These plants are also scattered by seed.
To exterminate the perennial weeds plow shallowly and expose the
plants to the sun; give frequent cultivation.

280 WEED FLORA OF IOWA

Wig. 162. Ground Cherry (Physalis lanceolata). Common in gravelly and
sandy soils; waste places and gardens. 1, leaf; 2, flower.
(Photographed by Quade. Drawing by Charlotte M. King.)

Fig. 162A Figure 162B

Fig. 162-A. Trichome or plant hair from leaf of Ground Cherry (Physalis
heterophylla).
(Drawing by Charlotte M. King.)
Fig. 162-B. Distribution of Ground Cherry.

DESCRIPTIVE MANUAL 281

Fig. 162-C. Distribution of Virginia Ground Cherry (Physalis virginiana).

Common Nightshade or Stubbleberry (Solanum nigrum L.).

Description.—Annual, low-branched and often spreading; glab-_
rous or hairy, hairs roughened on the angles; leaves ovate, petioled,

Fig. 163. Black Nightshade (Solanum nigrum). Shady places, gardens and
fields.
(Photographed by Colburn.)

282 WEED FLORA OF. IOWA

+ 2a am 7 Sel S|
é 83 ws ZN +
Kossuth SZ
OBrien i Wray
tr). \
«,
Me ==
Uy Yo biowe erty ie ie
/da .
= . en
eeCne = . 4
: Ame: . o ey
ere Cinte
oruradow "
Des) Mor 5 od ;
Heohktih oe
rate Bz e

AN
Y \

AS SN
AWAY)

Fig. 168-B. Black Nightshade (Solanum nigrum).

DESCRIPTIVE MANUAL 283

flowers white in small, umbel-like, drooping, lateral clusters; calyx
spreading, the lobes obtuse, much shorter than the white corolla;
= glabrous, globose, black; occasionally large.

- Distribution—Found in northern United States; abundant
everywhere in Towa in shady grounds and fields. A cosmopolitan:
weed.

Horse Nettle (Solanwm carolinense L:).

Description—aA deep-rooting perennial, propagating freely by
its underground root-stocks, the running roots often being 3 ft.
long; stem 1-2 ft. high, somewhat straggling, half shrubby at the
base; stem hairy or merely roughish with minute hairs which are
star-shaped, also armed with numerous stout, subulate, yellowish
prickles; leaves oblong or sometimes ovate, obtusely sinuate-toothed
or lobed, or deeply cut, 2-4 in. long; flowers borne in one-sided
racemes; calyx consists of slender lobes, ¢orolla light blue or white,
an inch or less in diameter ; flowers followed by yellow globose ber-
ries 14-84 in. in diameter; small yellowish seeds, a little less than
1/,, in. long, minutely foudhened: Flowers and yellow berries
resemble those of the potato. The spiny character of the leayes and
the further resemblance of the flower to the potato should render
it easy of, detection.

Distribution.—Horse nettle is indigenous to thé southern states,
but now oceurs from Connecticut to northern Iowa. This weed
is most abundant in southern Iowa and has been reported from
Floyd, Story, Boone and Linn counties; in the north half of the
state, however, it is a recent introduction. ead ew

ee aiinction —There are two ae ne ne ondedt Oi: one by
seeds, the other by perennial roots. It is so exceedingly tenacious
a weed, thatit is almost impossible to remove it when fully estab-
lished. ‘The following very suggestive methods have ‘been given.

Smothering. This is an effective method of removing the plant.
For this purpose probably rape or sorghum is the most suitable
crop. If the soil is not already rich, a liberal dressing of barnyard
manure should be applied during the winter or spring. The soil
should be harrowed or cultivated frequently until the time of seed-
ing, which may be any time during the months of May or June.
This cultivation will prevent the weed growth, and will also assist

284 WEED FLORA OF IOWA

in the retention of moisture. If the rape is sown in drills about
two pounds of seed per acre is sufficient quantity and three pounds
if sown broadcast. When the crop has attained a rank growth it
may be pastured or removed and fed to stock. Where land is lack-
ing in vegetable matter it is good practice to plow the crop under
when it is properly manured. The latter is not necessary when the
object is to destroy the nettle, as the rank growth of the crop is
very effective in completely smothering the weed.

Hoed crops. Planting of corn or roots is a method much in ~
vogue for the destruction of this vile intruder. As in the previous
method the plant should be kept down before seeding time. When
the crop appears above the ground the use of horse and hand hoe
should not be sparing. When the welfare of the crop prohibits the
use of the horse hoe, the hand hoe should be used at intervals until
the crop is removed; even after this, it is sometimes necessary to
give attention to the pest. There is no question about this mode of
treatment being effective if properly carried out, but often failure
results from negligence during the latter part of the season.

The Iowa Homestead suggests the following treatment: ‘‘Corn
land that has grown up to horse nettles this year should be burned
over, if possible, next spring, as this will destroy many of the
seeds. Afterwards the land should be plowed lightly and kept cul-
tivated at intervals until somewhat late in the season. A surface
cultivator will be all that is necessary, and this need not be run
deeper than two or three inches, just enough to effectively cut the
plants off below the surface. By checking the growth several times
before planting corn the root system becomes much weakened, so
that ordinary cultivation the remaining part of the season will often
keep them completely in check. Where nettles have been going to
seed for a number of years it may require considerable time to free
the land because these will germinate as they are brought near the
surface by the various plowings. However, it should be kept in
mind that any perennial root system may be killed outright in one
season if it is not allowed to develop roots or stems.’’

Buffalo Bur (Solanum rostratum Dunal.).

Description Herbaceous; woody when old, somewhat hoary or
yellowish, 8 in.-2 ft. high, covered with copious stellate pubescence ;
branches and main stems, when it begins to branch, covered with
sharp yellow prickles; leaves somewhat melon-like, 1-3 times pin-

Fig. 164. Horse Nettle (Solanum carolinense).
sometimes extend 3-4 feet in the soil.

the potato.

DESCRIPTIVE MANUAL

Common in southern Iowa.
(Photographed by Colburn.)

assuth | : S
OBrren 1%.
°
2 . Her
°
Tou Oy ubugue
57 loa 5 . 58 2
© reene oa
© = mes
=+ = . +> + ” <
°
thie he onsen
eel a? a id VF el aes} < . OM Ieee
aS SS [reokuk |» ge a
yatrawatidmie| / O é e hte 2 5
. : 5
+ + :
selene E ota
Page °, \aecah ; -
. we |. jecatur +
sO Olorailn ) E 3 il | ° o 8

Fig. 164-A. Distribution of Horse Nettle.

- 285

Deep rooted perennial, roots
Flowers and berries somewhat like

286 WEED. FLORA OF IOWA

Fig. 165. Buffalo Bur (Solanum .rostratum).. Pastures, gardens, railways, ete.
‘ (Photographed by Colburn.) :

CRETE

Fig. 165-A. Distribution of Buffalo Bur.

DESCRIPTIVE MANUAL 287

aatifid, lobes roundish or obtuse and repand, covered with soft
pubescence; hairs stellate, flowers yellow, corolla gamopetalous,
about an inch in diameter, nearly regular, the sharp lobes of the
corolla broadly ovate; stamens 5, declined, anthers tapering up-
ward, linear-lanceolate, dissimilar, the lowest much larger and
longer, with an incurved beak, hence the technical name rostratum ;
style much declined; fruit a berry but enclosed by the close-fitting
or prickly calyx, which has suggested the common name buffalo
bur; pedicels in fruit erect; seeds thick, irregular, round or some-
what longer than broad, wrinkled, showing numerous small pits
and surrounded by a gelatinous substance.

Fig. 165-B. Buffalo Bur (Solanum rostratum); a, general sketch showing
habit of plant; b, flower; d, seed natural size; c, seed enlarged.
(After Dewey, U. S. Dept. of Agr.)

288 WEED FLORA OF IOWA

Distribution.—Buffalo bur is originally native of the plains
region, between the Missouri river and the Rocky mountains. It
has spread eastward in the northern states and extensively in
' Texas, Mississippi and Arkansas. It is not infrequent from
Tennessee to New York. It has been found in Germany. ‘This
weed is widely scattered in small patches in many parts of the
state of Iowa.

Extermination—Inasmuch as this weed is an annual, it can be
easily exterminated by cutting off the young plants below the
ground and this should be done before the pods are formed. If
plants are older they should be cut off and burned.

The Iowa Homestead says concerning this weed: ‘‘On account
of the fact that the buffalo bur is an annual its destruction or
eradication is simply a matter of preventing it from maturing its
seed. Corn fields that are badly infested may need but little at-
tention after the regular time for laying the corn by, for which
purpose the one horse cultivator may be pressed -into use.’’

Dr. C. E. Bessey in Breeder’s Gazette recommends as follows:
‘“To get rid of it the best thing is first not to allow the weed to
get a good start, as its deep roots are hard to get out. Second, if it
has a good start, the plants must be cut down frequently so as to
prevent their seeding and thus starting new plants. In the third
place, the deep roots must be killed by digging out or by smother-
ing. This can be done by using a very heavy dense crop like some
of the sorghums, or by covering the patch with wet manure. Of
course constant stirring of the soil will kill them. It will pay to
watch this weed wherever it appears.’’

Purple Thorn-apple, Purple Stramonium, or Jimson Weed
(Datura tatula L.).

Description—A glabrous annual from a few inches to 5 feet
high ; stem purplish ; leaves thin, ovate, acute or acuminate; flowers
consisting of a 5-toothed calyx and a 5-lobed funnel form corolla,
with stamens included; filiform filaments inserted below the mid-
dle of the corolla tube; capsule globular, prickly, 4-valved and
2-celled. The common thorn-apple (Datura stramonium) is a glab-
rous annual with green stem, sinuate-toothed leaves and white
corolla.

DESCRIPTIVE MANUAL 289

Fig. 166. Purple Jimson Weed (Datura tatula). Barnyards, roadsides.
(Photographed by Colburn.)

er ee ————
a Mitchell
Kossuth
OBrien SS
utlor-|
u ou Cy i
Ida
weene id
4 | dames-
< ——
= . . Q Des) Moines
.
Poitawalta mre) 7
*
Page ature lima
S

Fig. 166-A. Distribution of Jimson Weed.

19

290 ; WEED FLORA OF IOWA

Distribution.—Both species abundant in field and waste places
from New England to North Dakota and Texas and naturalized
from Europe; originally native to India.

Fig. 166-B. Jimson Weed or Thorn-apple (Datura stramonium). a, flowering
spray; b, fruiting capsule.
(U. S. Dept. Agr.)

RASS
PACE

th

ny fis ml Sie val
ee

Fig. 166-C. Distribution of Thorn-apple.

DESCRIPTIVE MANUAL 291

Extermination.—Both of the jimson weeds are easily destroyed
by cultivation. They produce an enormous amount of seed which
probably retains its vitality for a considerable length of time. How
long, however, has not been determined.

SCROPHULARIACEAH, MULLEIN FAMILY.

Snapdragon and Simpson honey plant belong to this family.

Mullein (Verbascum thapsus L.).

Description.—A tall, densely woolly annual or biennial herb 2-6
ft. high; leaves oblong, thick, covered with branched hairs, the
basal leaves margined, petioled; flowers in long dense spikes; corolla

Fig. 167. Mullein (Verbascum thapsus). A hairy biennial, common road-
side weed; gravel hills along Mississippi river, old fields.
(Photographed by Colburn.)

292 WEED FLORA OF IOWA

Seem
oe

Figure 167A Figure 167B

Fig. 167-A. Glandular trichome from viscid pod of Moth Mullein (Verbascum
blattaria).
(Drawing L. H. Pammel and Charlotte M. King.)

Fig. 167-B. Distribution of Mullein.

rotate, yellow or rarely white; stamens unequal, the 3 upper
shorter, woolly, with short anthers; the 2 lower smooth with larger
anthers; trichomes many-celled, branched with central axis.

Distribution—From Nova Scotia west across the continent.
Southwest to Missouri and Kansas and Utah. Common in waste
places, especially in eastern Iowa.

Extermination.—Mullein is easily destroyed by cutting the plant
off a few inches below the surface of the ground. This may be
done in the autumn after the appearance of the root leaves, or in
the second season when the plant shoots up.

Toadflax (Linarva vulgaris Hill.).

4

Description.—Persistent, deep-rooted perennial, 114-214 ft. high,
with erect, slender stem; leaves smooth, sessile, crowded, alternate-
linear, somewhat fieshy ; flowers in racemes, showy, pale yellow and
orange lips; corolla 2-lobed, closed; seeds small, dark brown to
black and roughened; flowers from June to October.

Distribution.—Introduced from Europe first as a cultivated
plant from whence it has spread to roadsides, meadows, and waste
places. Somewhat widely distributed in this state, but particularly
common in Clayton, Allamakee and Winneshiek counties; local in
Story county.

DESCRIPTIVE MANUAL 293

Roadsides, gardens,

Fig. 168.. Toadflax or Butter and Eggs (Linaria vulgaris).
etc. ier
(After Clark and Fletcher.)

294 WEED FLORA OF IOWA

Fig. 168-A. Distribution of Toadflax.

Extermination.—F letcher and Clark recommend as follows:
‘“‘Short rotation of crops with deep, thorough cultivation in spring
and fall will suppress it. Hand-pulling when the soil is wet is
effective in pasture lands that cannot be cultivated. Badly in-
fested meadows or pasture lands should be brought under cultiva-

tion by plowing in July, summer-fallowing until autumn, and
planting with hoed crop the following spring.’’

Simpson Honey Plant (Scrophularia marilandica L.).

Description—aA glabrous, somewhat glandular, pubescent peren-
nial, 3-5 ft. high; stems 4-angled; leaves thin, ovate, or ovate-lan-
ceolate, sharply serrate; flowers cymose; calyx lobes ovate, about
the length of the tube, corolla brownish purple; capsule subglob-
ular; seeds small, numerous.

Distribution—Common in woods and thickets from Maine to
the Rocky mountains. Abundant in woods and adjacent fields.

Extermination.—Simpson honey plant produces a large number
of small seeds. However, but little is known of their vitality.. The
weed is easily killed by cultivation and easily crowded out by
clover and small cereals.

The Scrophularia leporella Bicknell, is similar as regards the
foliage, the rudimentary stamen is, however, yellowish-green in-
stead of brownish-purple as in the 8. marilandica.

DESCRIPTIVE MANUAL

296

Fig. 169. Simpson Honey Plant (Scrophularia marilandica).

waste places.
(Photographed by Colburn.)

Woods and

Vwirchel eel |

aL ( = “S C} \
IS Buller. aN =
SINE

ida

J

S yk
i ¢ |
Forrawattd mie

Fig. 169-A. Distribution of Simpson Honey Plant.

296, WEED FLORA OF IOWA
Purslane Speedwell, Neckweed (Veronica peregrina L.).

Description.—A glabrous, glandular, or nearly smooth, branch-
ing annual 4-9 in. high; leaves petioled, upper oblong, linear and
entire; floral leaves like those of the stem but reduced; flowers
axillary and solitary, white; capsule orbicular.

Distribution—A common weed in fields in Iowa and in eastern
North America from Nova Scotia southward; also west to Texas and
the Pacific coast. Found in South America and in Europe; cos-
mopolitan. ;

Extermination.—The seeds are produced abundantly, but young
as well as older plants are easily killed by cultivation.

Vig. 170. Speedwell (Veronica peregrina). Common in gardens and fields in
early spring.
(Photographed by Quade.)

PLANTAGINACEAE, PLANTAIN FAMILY.

The family contains few plants of economic importance. The
seeds of a few species are used as medicine.

DESCRIPTIVE MANUAL - 297

Fig. 170-A. Distribution of Speedwell.

Common Plantain (Plantago major L.).

- Description. —A smooth, glabrous perennial with short root-
stocks; leaves with a long channeled petiole, ovate, oblong or oval;
spike long, linear, cylindrical, capsule circumscissile near the mid-
dle; flowers proterogynous; seed smooth, angled, reticulated : tri-
chomes short, several-celled, from a broad base..

- Distribution—Common plantain is widely distributed in North

America from the Atlantic to the Pacific. Perhaps native far
northward; probably naturalized in Iowa, It is found in every
county in the state; frequent in dooryards, fields and pastures.

Extermination.—Usually not a difficult weed to exterminate in
cultivated fields.

Clark and Fletcher recommend the following treatment: ‘‘Hoed
crops every four years will keep this weed in ‘check. Working
with a broad-shared cultivator, followed by a. harrow, to drag the
plants with their fibrous roots to the surface, is recommended for
spring cultivation. Plantain in lawns may be weeded out when
the soil is firm by forcing a small implement like a chisel, with
a half-round blade having a point like the tip of a spoon, between
the soil and the fleshy crown of the weed to a depth sufficient ‘to
break the plant away from its fibrous roots without disfiguring the
turf. <A teaspoonful of salt applied to. the crown of small plants
in pot dry weather will kill Te without seriously injuring the
erass.’

298 WEED FLORA OF IOWA

COMMON

(Plantago

Fig. 171. Common Plantain (Plantago major). Common in dooryards, wast
places, etc.
(After Clark and Fletcher.)

DESCRIPTIVE MANUAL 299

Fig. 171A Figure 171B

Fig. 171-A. Hairs of Common Plantain.
(Drawing by L. H. Pammel. and Charlotte M. King.)

Fig. 171-B. Distribution of Common Plantain.

Chemical Composition—According to the report of the Bussey
Institution* the chemical composition is as follows:

FRESH OR AIR DRY MATERIAL.

5 : z Nitrogen free
Water | Ash | Protein | Fiber. | Extract Fat
81.44 | 2.16 | 2.65 | 2.09 | 11.19 | ee FAY,
WATER FREH SUBSTANCE.
| 11.7 | 14.3 | 11.3 | 60.2 | 25

Rugel’s Plantain (Plantago Rugelu Dec.).

Description.—Perennial, much like the preceding, but leaves and
petioles commonly purplish; spikes less dense; sepals oblong; cap-
sule about twice as long as the sepals; circumscissile much below
the middle; flowers proterogynous; seed oval or oblong, not reticu-
lated.

Distribution—Common in fields and waste places from Maine to
Texas, South Dakota:and Ontario. Common in Iowa.

Extermination—This weed may be exterminated in the same
manner as the preceding species.

*Bull. 1877:117, Jenkins & Winton. Office of Experiment Stations, Bull 11

300

WEED FLORA OF IOWA

Ay

x
iW a NG

Rugel’s plantain (Plantago rugelii Decne.)
(Mich. Agr. Exp. Sta.)

Fig. 172.

DESCRIPTIVE MANUAL 301

ena
aS Tee

a My

Fig. 172-A. Distribution of Rugel’s Plantain,

Rib Grass (Plantago lanceolata L.).

Description.—A. hairy, scapose, perennial with ‘flowering heads,
1-21% ft. high; leaves lanceolate or lance-oblong; spike thick, at
first capitate, becoming cylindrical ; bracts and sepals scarious; seed
smooth, brownish, hollowed on the face; trichomes simple, long,
slender-pointed.

Distribution—Buckhorn or rib grass is native to Europe and
has long been known as a troublesome weed in the eastern states;
it is particularly abundant in Ohio and New York and is frequent
in the east; in the Rocky mountains and on the Pacific coast. In
Towa it has been distributed widely with clover and will be found
in clover meadows in many parts of the state.

Extermination.—This weed is a persistent perennial in fields,
lawns and clover meadows. Nothing but thorough cultivation will
destroy it. In seeding to clover use only pure and clean seed.

Clark and Fletcher recommend as follows: ‘‘Sow clean seed.
In common with other species of plantain, this weed is easily sup-
pressed by hoed crop and short rotation. It is prevalent almost ex-
elusively in clover crops, in which it increases rapidly by the dis-
tribution of its seeds with commercial clover seed, the market value
of which is depreciated by this impurity. Farmers who use only
first quality red clover seed and who pull the first plants of this
weed that occur in the clover seed crop will soon rid their farms
of this pest.’’

WEED FLORA OF IOWA

302

Common in clover meadows.

(Photographed by Colburn.)

Fig. 173.

Buckhorn (Plantago lanceolata).

—-

|

7

Fig. 173-A. Distribution of Buckhorn.

DESCRIPTIVE MANUAL 303

Chemical Composition.—The chemical composition of rib grass,
grown in New Hampshire, according to Rept. U. 8. Dept. Agr.,
1879; p: 121, is as follows :*

FRESH OR AIR DRY MATERIAL.

: : Nitrogen free
Water | Ash | Protein | Fiber | Extract Fat
7.85 | 6.90 | . 9.80 | 20.24 | 51.10 | 4,11
WATER FREE SUBSTANCE.
ec ae fs

Prairie Plantain (Plantago purshii R. & S.).

Description.—A silky, green annual with slender scapes; leaves
linear, acute, with marginal petioles; spikes usually cylindrical,
villous with rigid bracts; flowers of two kinds on different plants;
most of them cleistogamous; sepals oblong, obtuse; corolla lobes
broadly ovate; stamens 4; capsule oblong, obtuse, circumscissile at
about the middle; seeds convex on the back, deeply concave on the
face.

Distribution—Common westward from Ontario and Illinois to
British Columbia, Texas and Mexico. Sometimes a troublesome
weed in Missouri and Nebraska. Found along railways in Iowa.

Extermination.—This little plantain is not likely to give much
trouble unless the seeds are able to retain their vitality for a con-
siderable length of time. The plant is easily destroyed by culti-
vation.

*Jenkins and Winton. Bull. Off. Exp. Sta. 11:79.

WEED FLORA OF IOWA

304

Prairie Plantain (Plantago purshii).

(Drawing by Ada Hayden.)

DESCRIPTIVE MANUAL 305

Fig. 174-A. Distribution of Prairie Plantain.

Bracted Plantain (Plantago aristata Michx.).

Description.—A loosely hairy, green annual, becoming glab-
rous with age, leaves 1-3-nerved, oblong, linear, or filiform; spike
slender, cylindrical, with narrow linear bracts, much longer than
the flowers. Flowers of two kinds with reference to the length of
anthers and filaments on different plants, mostly cleistogamous;
corolla lobes broad and rounded; seeds 2, smooth, light brown,
with a ring on the hollowed portion. The P. purshw is much like
bracted plantain except that its leaves are silky villous and slender ;
spike dense.

- Distribution—The bracted plantain is common in southern Iowa
and is spreading to many other parts of the state with clover seed;
on prairies, Illinois to Louisiana, naturalized eastward. The P.
purshu is found chiefly along railroads where it has been intro-
duced; common; native from western Minnesota and Iowa to the
Pacific coast.

Extermination.—Only clean clover seed should be used. Easily
exterminated by cultivation. Practice rotation of crops, oats, corn
and clover.

Wallaces’ Farmer says concerning its extermination: ‘‘The en-
tire southern country seems to be infested with bracted or lance-
leaved plantain, and seed coming from the south should always be
regarded with suspicion. It is one of the worst weeds that can get
on the farm. Cut the hay, plow up the land, put it in wheat, and
don’t undertake to take a crop of clover seed from that land.

20

306 WEED FLORA OF IOWA

Fig. 175. Bracted Plantain (Plantago aristata). A common weed in clover
fields in southern Iowa and in waste places.
(Photographed by Colburn.)

OBnen

Fig. 175-A. Distribution of Bracted Plantain.

DESCRIPTIVE MANUAL 307

When this weed grows over the whole field the only thing to do
is to put it through a course of rotation. Where there is only a
stalk here and there it may be taken out with a ‘spud,’ which is
simply a two-inch chisel with a handle, by means of which the
farmer can cut out rapidly many of these weeds, but where it is
scattered over the field the only way is to put it through a course
of rotation.’’

CAPRIFOLIACEAE, WOODBINE. FAMILY.

Contains a number of cultivated ornamental plants like the coral
honeysuckle, bush honeysuckle, elder, etc.

Indian Currant, Coralberry (Symphoricarpos orbiculatus Moench. ).

Description—A shrub 2-4 feet high; purplish, usually pubescent
branches; leaves oval or ovate, entire or undulate, nearly glabrous
above, pubescent underneath; flowers in short axillary clusters;
corolla bell-shaped, sparingly bearded, pinkish, stamens included;
fruit a purplish berry.

Distribution.—Rocky woods and along streams; from New Jersey,
Illinois, South Dakota, Nebraska to Texas and Georgia. This weed
is common throughout the southern part of the state of Iowa and
is often most troublesome.

Extermination —Fields that are infested with this weed must be
- broken up with a breaking plow and subsequently disked so that
the roots may be brought to the surface and exposed to the sun. It
may be necessary to disk once or twice more before planting the
crop.

COMPOSITAE, SUNFLOWER FAMILY.

Includes comparatively few economic plants, such as lettuce, arti-
choke, pyrethrum, sunflower; quite a number such as gumweed

- (Grindelia), tansy and absinth, are used in medicine; several, like

daisy, cosmos, coreopsis, aster and goldenrod, are ornamental.

308 WEED FLORA OF IOWA

Fig. 176. Indian Currant (Symphoricarpus orbiculatus).

Fig. 176. Distribution of Indian Currant.

DESCRIPTIVE MANUAL 309
Ironweed (Veronia baldwini Torr.).

Description—A roughish, pubescent, perennial 3-5 ft. tall;
leaves lance-oblong or ovate, denticulate; heads in open, cymose
clusters, about 25-flowered; involucre hairy-tomentose; bracts
squarrose, purplish or greenish; involucre acuminate.

Distribution—Common from Maine to Missouri and southward.
It is found in central Iowa, from Webster county southward and
along Missouri river to Council Bluffs.

Extermination.—Frequently a troublesome weed. Usually not
difficult to exterminate in cultivated fields.

Fig. 177. Ironweed (Vernonia baldwini). Common in low pastures. Flowers
in heads.
(Photographed by Colburn.)

310 WEED FLORA OF IOWA |

| Pet ee na
See ae
CUTS

Fig. 177-A. Distribution of Ironweed.

Western Ironweed (Vernonia fasciculata Michx.).

Description.—A bushy perennial 3-5 ft. high; leaves linear to
oblong-lanceolate, long, acuminate, smooth or nearly so, denticulate ;
heads short-peduncled, 20-30-flowered, bracts of the involucre ap-
pressed, ovate or oval, acute, ciliate, the uppermost somewhat
mucronate.

Distribution—Common in the Mississippi valley, especially on
low, alluvial grounds from Ohio to North Dakota, south to Ken-
tucky and Texas; frequent in all parts of Iowa.

Extermination.—This perennial weed, though abundant in pas-
tures and low meadows, soon succumbs to cultivation.

Wallaces’ Farmer says concerning its destruction: ‘‘An occa-
sional cutting of ironweed is useless. If you are to keep it down
by strangulation, then you must keep at it until the weed is
strangled.

‘Tf we had some permanent pasture that was covered with iron-
weed, we would try sheep. There are a few weeds that sheep
will not eat. They will probably not make a very good living on
ironweed alone, although we recently saw some sheep that ap-
parently had nothing else to live on trimming up ironweed alone.
But sheep will eat almost any weed that grows out of the ground,
barring thistles, mullein and buffalo berry. It requires about two.
years of sheep pasturing to get rid of ironweed. We know of no
other way in which it can be done so easily.”’

DESCRIPTIVE MANUAL

311

Fig. 178. Common or Western Ironweed (Vernonia fasciculata). A perenniah

weed with purple flowers.

(Photographed by Colburn.)

seats Be ee eS :
+ a Mitchell .
— e = e . . . Oy
Kossuth °
+ °
3 | + te iS . “NS aE
ae @
se . juller\ eo .
. e
eo oe
2 eo Gubugue
e = ° . .
5
.
°.
He :
i. reene joo, |e te .
2 A ames+ |) + AG
S 2 Ae |th Se eS 2 TY Clinton
° r ‘ ‘ 2. M ah ee . maa
oes) Moi
= 2 Tudactine
iKeakizk :
fawattd mie) . cy 3 =
u 2 ny +
7 = y e
e/* ts « « . | . o Henry .
e .
of Wrage |. Decatur seats nas
fet | eed ee . wee (| eal pA,

Fig. 178-A.

Distribution of Western Ironweed.

In low pastures and meadows.

312 WEED FLORA OF IOWA
White Snakeroot (Hupatorium urticaefoliwm Riech.).

Description.—Perennial, with smooth, branching stem 15-40 in.
high; broad, ovate, coarsely and sharply toothed, pointed, long-
petioled leaves; flowers in compound, cymose clusters, white.

Distribution.—Pennsylvania, Virginia, westward; reported from
many places in Iowa.

Extermination.—This perennial weed is easily killed by cultiva-
tion. It is common in woodlands. It is mentioned here because
of its supposed poisonous nature.

a
ee
oe

Fig. 179. Beneset or White Snakeroot (EHupatorium wurticaefolium). Wood-
land pastures.
(Photographed by Quade.)

DESCRIPTIVE MANUAL . 313

Figure 179A Figure 179B

Fig. 179-A. Distribution of White Snakeroot.

Fig. 179-B. Boneset (Hupatorium rotundifolium).
(Drawing by Lois Pammel.)

Goldenrod (Solidago canadensis L.).

Description—A rough, hairy, pubescent perennial 3-6 ft. high;
lanceolate, pointed, sharply serrate leaves, especially pale in color,
pubescent beneath and rough above; heads in recurved racemes
forming panicles; ray flowers yellow; trichomes gseveral-celled; cells
short, walls pitted.

Distribution —Most widely distributed of the goldenrods from
the Atlantic to the Rocky mountains; common in every part of
Iowa, especially in Story, Boone, Clinton, Linn, Allamakee, Potta-

wattamie, Woodbury, Cerro Gordo and Marshall counties.

Extermination.—This weed is quite largely spread by ‘‘seeds,’’
but is not difficult to kill by cultivation, although it sometimes
persists in fields for some years. Prevent the carrying of ‘‘seeds’’
and give thorough cultivation.

- 314 WEED FLORA OF IOWA

Fig. 180. Canadian Goldenrod (Solidago canadensis). Roadsides and woods.
a, hairs of leaf.
(Photographed by Colburn, a, hairs drawn by Charlotte M. King.)

ARBGk: ets

Sune se

et TEE
pe ae PN

Fig. 180-A. Distribution of Canadian Goldenrod.

DESCRIPTIVE MANUAL 315
Goldenrod (Solidago serotina Ait.).

Description.—A tall, stout perennial 4-6 ft. high; often glaucous;
leaves smooth on both sides, lanceolate to oblanceolate, taper-
pointed, sharply serrate; heads in open panicles, pubescent, bracts
linear ; ray flowers 7-14, yellow.

Distribution—Common from New England southward and west-
ward to the Rocky mountains and Colorado; common in all parts
of the state of Iowa.

Extermination.—Succumbs readily to cultivation, spreads by its
seeds and root-stocks.

Fig. 181. Smooth Goldenrod (Solidago serotina). Abundant in low grounds
along streams.
(Photographed by Colburn.)

316 WEED FLORA OF IOWA

Fig. 181-A. Distribution of Smooth Goldenrod.

Large Yellow-flowered Goldenrod (Solidago rigida L.).

Description—A rough and somewhat hoary perennial, minutely
pubescent; stems stout, 2-5 ft. high, very leafy ; leaves oval or ob-

Fig. 182. Large-flowered Goldenrod (Solidago rigida). In pastures and road-
sides.
(Photographed by Colburn.)

DESCRIPTIVE MANUAL 317

Fig. 182-A. Distribution of Large-flowered Goldenrod.

long, feather-veined, thick and rigid, the upper sessile; heads
large, collected in a large compound corymb, terminating the stem.

Distribution—Abundant in dry soils from New England to
Manitoba, Dakota, Nebraska and Missouri; common in pastures in
Jowa, in Story, Boone, Polk, Linn, Marshall, Hardin, Cerro Gordo,
Winnebago, Emmet and Woodbury counties.

Extermination.—Though it is often a very troublesome weed in
pastures it is easily killed by cultivation; spreads largely by
““seeds.”’ ;

Many-flowered Aster (Aster multiflorus Ait.).

Description—A pale or hoary pubescent, branched perennial,
9 in-114 ft. high; heads on spreading, racemose branches; leaves
rigid, crowded, spreading, with ciliate margins; ray flowers white,
small.

Distribution—Common along roadsides and fields, gravelly
knolls, ete.

Extermination—Though abundant in fields readily succumbs to
cultivation.

318 WEED FLORA OF IOWA

Tig. 188. White or Many-flowered Aster (Aster multiflorus). Common on road-

sides.
(Photographed by Quade.)

. ae titchell
. 5 \ Soll. . 5 A
2 : 0 = 2
q F Kossuth =
' 2 OBrien c , + re :
f| . |t 6 +. Nee .
i - = Sule
tee = e o uHler 2 2 .
Ty + = a . O,2 Gubegue
“S| Joa 5 Sl eal = : 2
= ze = ce aah .
a . .
oo °
fate O aes * Rdmes |) + ees < se
3 : Shak. ONS clinton of
na 2NG 3
= el © Pennsbm | 5
a es| Maines @ . ac Sy
e . . o + E e
° SS [reokuk ‘o
wattd me| 7° . : ale 2 5
3 o .
>
o - . . . - = . ary
a = ey 4
°{ Vage | « [Deatur| © 2 . x
e O |Pso 2 a
+

Fig. 1838-A. Distribution of White Aster.

DESCRIPTIVE MANUAL _ als)
Willow-leaved Aster (Aster salicifolius Ait.).

Description.—A branched, leafy perennial 2-8 ft. high; leaves ob-
long to narrowly lanceolate, pointed, entire, or slightly serrate, firm,
often scabrous; heads racemose, clustered; ray flowers purplish.

Distribution.—Common in low grounds, thickets or borders of
fields from New England to Wisconsin and Minnesota. An allied
species, A. pamiculatus Lam., is much like A. salicifolius except that
the leaves are more pointed, serrate and less scabrous. It is a very
variable species, with distribution similar to that of A. multiflorus.

Externunation.—EHasily exterminated by cultivation.

Fig. 184. Willow-leaved Aster (Aster salicifolius). Common in low grounds,
(Photographed by Quade.)

320 WEED FLORA OF IOWA

UF

nS

Ee

Wig. 185. Aster paniculatus. a, Plant Hair. Common in low grounds every-
where in Iowa. White ray flowers, sometimes purplish.
(Photographed by Colburn. Drawing by Charlotte M. King.)

The Aster tradescanti L., is closely related to A. pamculatus, but
has smaller leaves and shorter rays. The leaves are lanceolate to
linear. The bracts are linear or acutish. 5

DESCRIPTIVE MANUAL 321

Whiteweed or Fleabane (Hrigeron annuus Pers.).

Description.—A sparingly pubescent annual 3-5 ft. high; leaves
thin, coarsely and sharply toothed, the lower one ovate, or ovate-
lanceolate, acute, and entire on both ends; heads corymbed; rays
white, tinged with purple.

Distribution—This weed occurs from New England to Texas.
Common in the Mississippi valley. Common throughout the state
of Iowa, particularly in timothy and clover meadows. This weed
is also naturalized in Europe.

Extermination.—Both this and EH. ramosus are easily exter-
minated by thorough cultivation. They are seldom troublesome out-
side of meadows, though in some parts of Iowa the meadows and
pastures are white with flowers of these species.

Fig. 186. Whiteweed or Daisy Fleabane (Hrigeron annuus). Common in clover
and timothy meadows.
(Photographed by Colburn. Drawings a@ and b by Charlotte M. King.)
21

322 WEED FLORA OF IOWA

Fig. 186-A. Distribution of Whiteweed.

Wallace’s Farmer states concerning its eradication: ‘‘One of the
worst enemies of the meadow, and especially the timothy
meadow in the west, is a peculiar form of daisy to which farmers
give the name of whiteweed. It may be seen in full bloom about
the time timothy heads out, and if not dealt with on its first ap-
pearance in the timothy field it is only a question of time when
the hay will be from one-fourth to one-half whiteweed. If the
farmer is vigilant and goes through and pulls out these weeds on
their first appearance, he can protect his timothy meadows. If he
fails to do this, it is only a question of time when he will have to
plow them up.”’

Daisy Fleabane (Erigeron ramosus (Walt.)_B S P).

Description.—This resembles the preceding species except that
the stem and leaves are somewhat more hirsute and hairy; leaves
roughish, entire or nearly.so, the upper lanceolate, the lowest ob-
long or spatulate; flowers white and smaller than in the preceding
species.

Distribution.—Daisy fleabane is native from New England to
Arkansas. Common in Jowa, particularly in drier situations, clover
meadows and timothy fields.

Extermination.—This weed is common in timothy and clover
meadows. The seed is often found in clover and timothy seed.
Care should be used to sow only clover and timothy seed that does

DESCRIPTIVE MANUAL 323

fig. 187. Daisy Fleabane (Hrigeron ramosus).
(Mich. Agr. Coll. Exp. Sta. Bull.)

324 WEED FLORA OF IOWA

Nom _ E: | Keokuk] Wes
ro: wee

\ ee tiene! - |= | Stee

Fig. 187-A. Distribution of Daisy Fleabane.

not contain these weed seeds. This weed is easily destroyed by cul-
tivation. The meadows are sown from seed coming from the neigh-
boring roadside or field. The weeds should, therefore, be cut in
waste places. |

Horseweed (Hrigeron canadensis L.).

Description.—Bristly, hairy, or sometimes glabrate stem, 1-6 ft.
high, simple or paniculately branched; leaves usually pubescent or
ciliate, the lower spatulate, incised or entire, obtuse or acutish,
the upper generally linear and entire; heads numerous, with in-
conspicuous white ray flowers shorter than the pappus; pappus
simple; trichomes several-celled, straight with long cells; curved
with short cells.

Distribution.—Horseweed is common throughout eastern North
America; naturalized in Europe, the Rocky mountains and along
the Pacific coast. Everywhere in Iowa in waste places and in eul-
tivated fields.

Extermination—This weed is an annual and is very easily de-
stroyed. Cutting off just below the surface of the ground will
exterminate it, provided, of course, that the new seeds are not per-
mitted to re-seed the soil. The weed is common everywhere and
the fact that it is so easily blown by the wind makes it difficult to
keep it in check.

, DESCRIPTIVE MANUAL 325

Fig. 188. Horseweed (Hrigeron canadensis). In fields and waste places.
(Mich. Agr. Exp. Sta.)

326 WEED FLORA OF IOWA

Fig. 188-A. Distribution of Horseweed.

Great Ragweed (Ambrosia trifida L.).

Description.—A stout, scabrous, hispid or nearly glabrous an-
nual, 3-12 ft. high; leaves all opposite and petioled, 3-nerved, deeply
3-5-lobed; lobes ovate-lanceolate and serrate, upper leaf sometimes
ovate and undivided; flowers monoecious, staminate, borne in spikes
surrounded by the larger bract-like leaves; involucre turbinate to
obovoid, 5-7-ribbed, beaked, each rib bearing a tubercle near the
summit; involuere enclosing a single oily seed.

Distribution—tThis North American weed is most abundant in
the Mississippi valley from Texas to Minnesota and in the Da-
kotas; however, it also occurs east from New England to Quebec.
It is abundant in every part of Iowa, especially along highways, in
erain fields and corn fields.

Extermination.—lt is certain that cultivating the young plants
followed by three or four other similar treatments will remove the
weed in a single season.

DESCRIPTIVE MANUAL 327

i

Wig. 189. Greater Ragweed (Ambrosia trifida), sometimes, but incorrectly,
called Ironweed. Common in fields, along roadsides; ete.
(Photographed by Colburn.)

Fig. 189-A. Distribution of Greater Ragweed.

328 WEED FLORA OF IOWA
Smaller Ragweed (Ambrosia artemisvifolia L.).

Description—A puberulent or hirsute annual, branched, 1-3 ft.
high; leaves thin, 1-2 pinnatifid; upper leaves alternate, lower
usually opposite, pale or canescent beneath; flowers monoecious,
staminate above and pisillate in lower axils of the leaves; fertile
heads obovoid or globose; short-beaked, 4-6 spined; trichomes sev-
eral-celled, cells short or long.

Distribution —Ragweed or hogweed is originally from Europe
but is common throughout eastern North America; also found in
the Rocky mountains, the Pacific northwest, and in Mexico, West
Indies and South America. It is common throughout the state of
Iowa in gardens and fields and is abundant in pastures.

Extermination.—This weed is too common in pastures, along
roadsides and in waste places. The weed is easily exterminated by
cutting the plants off below the surface of the soil. The commonly
used cultivator will destroy most of the young plants in a corn
field.

Clark and Fletcher recommend the following treatment: ‘‘Sow
clean red clover seed. Stubble lands where this weed is prevalent
should be shallow plowed directly after harvest, or, if seeded, the
autumn growth should be closely cut with a mowing machine
within two weeks after the grain crop is cut.’’

Wallaces’ Farmer says concerning this serious pest of the pas-
ture: ‘‘We suggested that the reason why the ragweed grows in
the blue grass pastures is because tor some reason the stand of
grass has been weakened and thus the ragweed seeds, which are
present in all cultivated soils in the west in great abundance, have
a chance to grow. We suggested further that the stand of grass
may have been weakened by overpasturing in a dry time, thus giy-
ing the sun opportunity to burn the roots and lower their vitality.
We suggested also that it may have been weakened by the ravages
of larve of the various insects known as the white grub worms.
We suggested still further that blue grass, not being able to ob-
tain nitrogen from the atmosphere, was nitrogen hungry, and there-
fore weak.

To meet all these various suggestions we proposed that farmers
whohave blue grass pastures of long standing should re-seed them
next year with one or other of the various kinds of clover, filling

DESCRIPTIVE MANUAL 329

Fig. 190. Small Ragweed or Hogweed (Ambrosia artemisiifolia). In pastures,
waste places, gardens and clover meadows.
(After Clark and Fletcher.)

330 5 WEED FLORA OF IOWA

EL

-

2

Figure 190A Figure 190B

Fig. 190-A. Plant hairs or trichomes of ragweed.
(Drawing by Charlotte M. King.)

Fig. 190-B. Distribution of Small Ragweed.

up the land with a preferred food for stock and at the same time
restoring the nitrogen content to the soil, enabling the blue grass
to make more rapid growth.

Fig. 191. A weedy Iowa field; Ragweed, Foxtail, Barnyard Grass, ete. The
seeds are sown in the field for next year.
(Photographed by Pammel.)

DESCRIPTIVE MANUAL 331

We did try it on a neighbor’s farm under the most disadvantag-
eous circumstances imaginable. The field was a pasture of blue
grass and wool grass with a very little white clover. The ground
was dry; as dry as we have ever seen it at that time of the year.
We found it easy even under these hard conditions to drill in clover
on this tough sod and cover it from an inch to an inch and a half,
using a Hoosier drill with two horses.

We found that the clover was dropped in the very bottom of
the slit made by the disk, a seed every two or three inches, using six
pounds to the acre. It lay there until the 23d of May, apparently
as dry as it came out of the drill, except in some of the lower spots,
where it had sprouted. The 23d of May there was a two-inch rain
on that field, and at once the clovers began to grow.”’

Perennial Ragweed (Ambrosia psilostachya D C.).

Description.—A branched hairy and rough perennial with slen-
der running root-stock, 2-3 ft. high; leaves once pinnatifid, acute
lobes, lower leaves incised; monoecious flowers, staminate flowers
with flattish involucres, involucre of fertile flowers, obovoid, tuber- .
cles absent or very small.

Distribution—Common on gravel hills and sandy plains from
[llinois, Wisconsin to the Saskatchewan to the Rocky mountains,
common gravel knolls and sandy plains; Clinton, Muscatine, Car-
roll, Kossuth, Pottawattamie counties.

Extermination.—Succumbs readily to cultivation.

332 WEED FLORA OF IOWA

Fig. 192. Perennial Ragweed (Ambrosia psilostachya). Pastures, drift soils,
roadsides.
(Photographed by Quade.)

Marsh Elder (Iva xanthifolia Nutt.).

Description.—An annual 1-8 ft. high; stem frequently pubescent
when young ; leaves opposite, rhombic, ovate, or lowest heart-shaped,
doubly ,serrate, or cut-toothed, obscurely lobed; upper surface
minutely scabrous, canescent beneath, especially when young;
petiole frequently ciliate at its upper end; flowers borne in spikelike
clusters forming a compound panicle; heads small, crowded; outer
bracts of the involucre broadly ovate, greenish; inner membrana-
cecus; achenes glabrate. This plant is also known botanically as
Cyclachaena xanthifolia Fr.

Distribution.—Common in the eastern Rockies, to Saskatchewan
and western Wisconsin, most abundant in Iowa along Missouri
river where it is troublesome in fields, along highways, and in

Fig. 193.

DESCRIPTIVE MANUAL

Halfbreed Weed, Marsh Hider (Iva xanthifolia).
Iowa, fields and roadsides.
(Photographed by Colburn.)

ee

e ale Mitchell
Kossuth = =
LS all eo Est

nD
aacliite

Keehn Aedscatine

fenry)

Fig. 193-A. Distribution of Marsh WHlder.

333

Common in western

234 WEED FLORA OF IOWA

yards, spreading into north and northeastern Iowa, Mason City and
Allamakee county and also in central Iowa, in Boone and Story
counties.

‘Extermination.—Marsh elder is an annual and hence thorough
cultivation for a single season will destroy it, provided it is not
allowed to form seeds.

Cocklebur (Xanthium canadense Maill.).

Description——A coarse, rough annual from 1-2 ft. high, stem
marked with brown punctate spots; leaves alternate, cordate or
ovate, 3-nerved, long petioled; flowers monoecious, staminate and
pistillate flowers in different heads, the pistillate clustered below;
involucre of staminate flowers somewhat fiat, of separate scales; re-
ceptacles cylindrical; scales of the fertile involucre closed; fruit
2-beaked, containing 2 achenes; bur densely prickly and hispid,
achenes oblong, without pappus.

The spiny clotbur XY. spinosum has spines in the axils of the
lanceolate leaves.

Distribution —Common in Mississippi valley from Texas to Min-
nesota and eastward. Common in fields in many parts of the
state, but more common in southern than in northern Iowa.

Extermination.—The best method of combating this weed is the
rotation of crops and clean culture. Where a field is in corn, the
field should be thoroughly cultivated and none of the plants al-
lowed to mature seed. If they cannot be caught by the cultivator,
it may pay to kill the remaining plants with a hoe, or to pull them
by hand. The corn should be followed with winter rye, and then
oats, using the oats as a nurse crop for clover and timothy. Leave
the field in meadow for at least two years and then if possible turn
it into pasture.

Mr. E. B. Watson found in soil badly infested with cocklebur
that clover seed would not germinate as well, and it is rather dif-
ficult to get clover to start in fields of this kind.

The Homestead says concerning the eradication of cocklebur:
‘‘Needless to say there is no easy way of eradicating the pest:
Where the winter wheat can be grown the following plan can be
depended upon. Start on fields that have been in small grain and
plow the land as soon as the crop is removed. Harrow as often

DESCRIPTIVE MANUAL 335

Fig. 194. Cocklebur (Xanthiwm canadense). Corn fields, roadsides, alluvial
bottoms.
(Photographed by Colburn. )

Vig. 194-A. Distribution of Cocklebur.

336 WEED FLORA OF IOWA

as necessary to kill weeds and put in wheat when the time comes.
The next season as soon as the wheat is harvested remove from the
field and go on with the mower. This will clip all or most all of
the young cocklebur plants, as well as other weeds, and following
this operation the stubble should be plowed as rapidly as possible
and prepared for another crop of wheat. Another season’s treat-
ment of this sort will generally reduce the burs to such an extent
that very few will be left and these can be pulled by hand.

Fig. 195. Spiny Clotbur (Xanthium spinosum). Waste places from Maine to
Kansas. Perhaps in southern Iowa.
(Photographed Ly Colburn.)

‘“One of our Nebraska subscribers, Mr. J. J. Bishop, stated some
time ago that he succeeded in almost clearing out a badly infested
field of cockleburs in two years by employing the following
method: Just as soon as the removal of the oat crop the soil was
plowed and prepared for winter wheat, this crop being sown at

DESCRIPTIVE MANUAL 337

the proper time. Mr. Bishop stated that before plowing this ground
after removing the oats the surface was covered with burs just
about as thick as they could grow. After harvesting the first crop of
winter wheat the soil was again plowed and seeded for the second
time to winter wheat. After this it was followed by corn and
other crops, with the result that even in the corn crop a very short
time spent in pulling burs freed the field entirely of these pests.’’

Mr. Albert Wiltz says in Wallaces’ Farmer: ‘‘When I moved to
this farm nine years ago the land was very badly infested with
cockleburs, and farmers told me that each bur had two seeds, one
growing one year and the other one the next year. I left a patch
of ground where the cockleburs were lying thick without a crop,
plowed in June once, and again in August. That settled the cockle-
burs. That year was a good corn year, with plenty of moisture.
Now, would not that way be the cheapest way to deal with them—
to put three years, yes, sometimes ten years’ fighting into one year?
That is, take a field one year to fight cocklburs, and finish it; next
year take another, and so on, if the farmer is a renter on a long
term lease or owns the land.”’

Wallaces’ Farmer states concerning the extermination of cockle-
bur: ‘‘If it is desirable to put some of this kind of land in alfalfa,
we would not put it in corn, but disk it every week or two during
the summer to sprout the burs, and then kill them by subsequent
disking, and keep on that way all summer, missing the crop for the
first year. Then in the fall, when the ground has sufficient mois-
ture, say in August or in the first part of September, seed it to al-
falfa alone, we would not sow alfalfa in the spring on that kind of
land; but by continuous summer cultivation it can be gotten in
shape to grow alfalfa and thus avoid not only cockleburs but also
eraberass, another great foe to alfalfa in that part of the country.

‘““Speaking now on the subject of cockleburs generally. Where the
land is not so badly infested with them as this farm seems to be,
and it is not desirable to grow spring grains and seed to clover, we
would make the stand of grain rather thin, put in a good seeding
of clover, put the clover deep enough to insure germination, use as
early a variety of grain as possible, get it off the land as soon as
possible, and then keep the cockleburs mowed down by chpping the
clover until a good stand is secured.’’

22

328 WEED FLORA OF IOWA
Ox-eye (Heliopsis scabra Dunal.).

Description—A rough, pubescent, perennial with opposite,
petioled, triple-nerved leaves; heads large, peduncled; seales of
involucre in 2-3 rows, nearly equal; ray flowers yellow, 10 or
more, fertile; achenes smooth, thick, 4-angled, truncate; pappus
chaffy or 2-3-toothed.

Distribution.—From New York west to Wisconsin, Minnesota
and British Columbia and southwest to Missouri, Kansas and
Arkansas.

Extermination—Though this weed is perennial, it is rather
easily destroyed by cultivation.

[iz 196. Ox-eye (Heliopsis scabra). a, plant hair or trichome. Common i!
orchards, waste places. Rather large yellow heads, and rough, opposite

leaves.
_ (Photograph by Colburn. a, drawing by Charlotte M. King.)

DESCRIPTIVH MANUAL 339

Fig. 196-A. Distribution of Ox-eye.

Blackeyed Susan, Nigger-head, Cone-flower (Rudbeckia hirta L.).

Description—A rough, hairy biennial 1-2 ft. high with stems
simple, or branched, bearmg a long pedunculate head; leaves
nearly entire, the upper sessile, oblong or lanceolate, the lower

Fig. 197. Black-eyed Susan (Rudbeckia hirta). Common in sandy fields.
(Photographed by Colburn.)

340 WEED FLORA OF IOWA

Fig. 197-A. Distribution of Black-eyed Susan.

petioled and spatulate; heads many-flowered, radiate, neutral;
receptacle columnar or conical; chaff hairy at tip, acutish; ray
flowers yellow, disk dull brown; achenes 4-angled; pappus none.

Distribution.—This weed is indigenous to the northern Missis-
sippi valley but has been naturalized eastward; is common through-
out the state of Iowa, occuring not only in meadows but in some-
what sandy fields in Linn and Muscatine counties.

Extermination.—This weed succumbs to cultivation but care
should be used in the sowing of clover seed as seed of this weed
is sometimes found with it. It is largely in this way that it has
been spread in the east.

Common Sunflower (Helianthus annuus L.).

Description.—A tall, rough annual, 6-8 ft. high, leaves 3-ribbed,
ovate or the lower cordate, serrate; large heads with yellow ray
flowers, disk flowers brownish.

Distribution Widely distributed west of Missouri river from
Saskatchewan to Texas, California and Mexico. Common in west-
ern Iowa, from Woodbury to Fremont county, occurring in fields
along highways, meadows, vacant lots and corn fields; widely scat-
tered, but not abundant in many other sections of the state, as
Boone, Story, Polk, Cerro Gordo, Webster, Lyon, Linn and Mus-
eatine counties.

Extermination.—The seeds of this plant do not retain their vi-
tality very long. The young plants are easily destroyed by cultiva-
tion. The plant should not be permitted to go to seed.

DESCRIPTIVH MANUAL 341

Fig. 198. Common Sunflower (Helianthus annuus). Common in western lowa
fields, roadsides.
(Photographed by Colburn.)

DS wel] ears ae

Sarr | Decatur af j
. Se ea | evs | ae ems I a ee ¢

Vig. 198-A. Distribution of Common Sunflower.

342 WEED FLORA OF IOWA

Fig. 198-B. <A patch of Wild Sunflowers (Helianthus annuus). Common in
K western Iowa.
(Photographed by Pammel.)

Prairie Sunflower (Helianthus petiolaris Nutt.).

Description.—The prairie sunflower is an annual 1-3 ft. high;
lower branches rough; stem leaves 1-3 in. long, oblong to ovate-
lanceolate, sparingly toothed, lower leaves abruptly contracted into
a long slender petiole; ray flowers yellow, disk flowers brownish ;
bracts lanceolate or oblong-lanceolate, usually not ciliate; head
flowers smaller than in common sunflower; flowers half an inch
or more in diameter.

Distribution.—Prairie sunflower is most abundant in dry prairies
from Minnesota to the northwest territory and Oregon and south
to Missouri. It has become naturalized more or less in Iowa.
It is not uncommon from Council Bluffs to Sioux City and
around Muscatine.

Extermination.—This weed is easily exterminated by cultivation.

DESCRIPTIVE MANUAL 343

Fig. 199. Prairie or Western Sunflower (Helianthus petiolaris). In Muscatine
Island and western Iowa. Similar to large Sunflower.
(Photographed by Colburn.)

ae
Mitche/

:
:
Lani

nN

ae |

Wig. 199-A. Distribution of Prairie Sunflower.

344 : WEED FLORA OF IOWA

Meadow or Saw-toothed Sunflower (Helianthus grosseserratus
Martens).

Description.—A tall, glabrous perennial 6-10 ft. high, bear-
ing numerous short peduncled heads; lower stem leaves 8-10 in.
long and petiole 1-2 in. long; leaves opposite or alternate with a
slender petiole, oblong, lanceolate, acuminate with sharp teeth, or
the upper merely denticulate, somewhat scabrous above, whitish
below; heads 14 in. high with deep yellow rays about an inch long;
bracts of the involucre slender.

Distribution.—Common in the central states and northward, also
westward to Texas. Abundant throughout the state of Iowa in
corn fields, low swales and roadsides, particularly in northern
Towa.

‘Fig. 200. Meadow Sunflower (Helianthus grosseserratus). Common in meadows,
pastures and fields.
(Photographed by Colburn.)

DESCRIPTIVE MANUAL 345

Fig. 200-A. Distribution of Meadow Sunflower.

Fig. 200-B. Meadow Sunflower (Helianthus grosseserratus). In meadows and
fields.
(Photographed by Pammel.)

346 WEED FLORA OF IOWA

Extermination.—It is certain that cultivating the young plants
followed by three or four other similar treatments will remove the
weed in one or at most two seasons. It would be well to use clover,
planted as a rotation after the field had had clean cultivation.

Artichoke (Helianthus tuberosus U.).

Description—A pubescent or hirsute perennial with tuberous
underground stems; leaves oblong-lanceolate or ovate-acuminate,
scabrous, minutely pubescent; flowers yellowish, large.

Distribution—Common from New York to Minnesota; in Iowa
most abundant in the northern counties; particularly troublesome
in Mitchell, Howard and Cerro Gordo counties. However, it is
not infrequent along highways and fields in many other parts of

the state.

Fig. 201. Artichoke (Helianthus tuberosus). Common in corn fields, road-
sides, ete., north Iowa.
(Photographed by Colburn.)

eee rn

DESCRIPTIVE MANUAL 347

Fig. 202. Artichcke (Helianthus tuberosus). In grain fields, roadsides and
waste places.

STN SNE De |
BASE PSA Nee
wi -

Fig. 202-A. Distribution of Artichoke.

348 WEED FLORA OF IOWA

Extermination—This is a most troublesome weed in corn and
smaller grain fields of northern Iowa. The somewhat thickened
underground stems spread the plant freely by cultivation. The
small-grain field should be plowed after the grain is removed,
then dragged so as to expose the ‘‘roots’’ to the sun. Before
planting corn in the spring run a disk over the field, then har-
row, plant to corn, and give thorough cultivation. When the weed
is very bad it may be well to get the field into meadow or pas-
ture.

Maximilian’s Sunflower «(Helianthus maximiliani Schrad.).

Description.Stem seabrous and hispid, 2-12 ft. high, the latter
height being obtained in alluvial bottoms; leaves usually alternate,
thick, becoming rigid, scabrous above, hairy beneath, lanceolate,

Fig. 203. Maximilian’s Sunflower. (Helianthus mazimiliani). Common in
meadows and fields of northern lowa. Yellow flowers, hairy elongated
leaves.

(Photographed by Colburn.)

DESCRIPTIVH MANUAL 349

ot Vt

o5 a)
=e] \e
=. Sa oy.
e Sa .
Ey lee
. *o
tame te +

Fig. 203-A. Distribution of Maximilian’s Sunflower.

narrowing at both ends, nearly sessile, entirely or sparingly dentic-
ulate; heads large, 14-34 in. high; short peduncle terminating the
simple stem and later appearing in the axils of lower leaves; invo-
lucre consisting of rigid bracts about 144 in. long; ray flowers
golden yellow, disk flowers brownish, flowering in late summer
and early autumn.

Distribution—This weed is common in places from Alberta
and Manitoba to Texas. In Iowa it is most abundant in the
northwestern and western counties, in the alluvial bottoms of
Missouri river and on high prairies of Pocahontas, Dickinson,
Emmet and Palo Alto counties; also found east in Worth, Howard
and Cerro Gordo counties. woe . ’

Extermination.—This perennial weed has the habit of the arti-
choke. The more or less thickened underground stems freely prop-
agate the plants. Give the field a shallow plowing then drag and
expose the roots to the sun for a few days. This will destroy the
most of the plants. If the field is put into corn give thorough cul-
tivation and follow corn with a small-grain crop and then clover.

Boot-jack (Bidens discoidea (T. & G.) Britton).

Description—A. diffusely branched annual with alternate, di-
vided leaves and slender petioles; leaflets ovate-lanceolate, pointed,
coarsely serrate, small heads of yellow flowers surrounded by a
double involucre, the outer of 4 bracts; achenes linear, wedge-
shaped, smooth or tuberculate, bearing a pair of short, upwardly
barbed awns.

350

Rig. 204.

WEED FLORA OF IOWA

Tall Boot-jack or Spanish Needle (Bidens discoidea).
corn fields, pastures, and meadows.
(Photographed by Colburn.)

ab
alk

ERY

Fig. 204-A. Distribution of Tall Boot-jack.

Commcn .in

eB ec i

DESCRIPTIVE *MANUAL 351

Distribution.Moist situations from New England to Missouri.
Common in southern Iowa.

Externunation—This annual is most abundant in low fields. It
succumbs readily to cultivation. The plants should not be allowed
to go to seed as the seed is scattered by animals; its spreading,
therefore, can be prevented by cutting the plant off close to the
surface of the ground when it begins to blossom.

Beggar-ticks, Stick-tight, Boot-jack (Bidens frondosa L.).
Description.—A branching, hairy or smooth annual 2-6 ft. high;

leaves petioled, 3-5-divided, terminal leaflet long-stalked, pointed,
coarsely toothed, frequently divided again; rays small, yellow invo-

Fig. 205. Boot-jack, Spanish Needle, (Bidens frondosa). Common in gardens.
The “seeds”, more properly achenes, are scattered by animals.
. (Photographed by Colburn.)

Ww
Oo
bo

WEED FLORA OF IOWA

Fig. 205-A. Distribution of Boot-jack.

lucre double, the outer foliaceous; bracts ciliate, longer than the
head; receptacle flattish with deciduous chaff; achenes narrowly
acuminate, 2-awned, the awns downwardly barbed.

Distribution.—Widely distributed in moist places throughout
the northern states; often a very troublesome weed in gardens. It
is widely scattered because of the ‘‘seeds’’ adhering to clothing,
pelts of animals, ete.

Extermination.—Boot-jack is easily exterminated by cultivation.
The weed is disseminated by animals and man. It would be well
to cut off the plant close to the surface of the ground when in
flower.

Tickseed (Bidens aristosa (Michx.) Britton).

Description —A._ smoothish, slightly pubescent, annual 2-4 feet
high; leaves 1-2-pinnately, 5-7-divided, petioled; leaflets lanceolate,
cut-toothed or pinnatifid; heads panicled-corymbose; scales of the
involucre in 2 series, the outer about as long as the inner, ciliate;
ray flowers conspicuous, yellow; achenes obovate with ciliate mar-
gins, usually with 2 divergent teeth; a somewhat showy plant with
yellow flowers.

Distribution—From Michigan and southern Iowa to Kansas
and Texas. Abundant in Missouri; probably indigenous to south-
ern Iowa; in recent years has made its appearance in Wapello,
(Panensi Marion, (Pammel) Polk Ca and Decatur (Ander-
son) counties.

23

DESCRIPTIVE MANUAL

. 206. Tickseed (Bidens aristosa).
(Mich. Agr. Exp. Sta.)

353

354 WEED FLORA OF IOWA

Fig. 206-A. Distribution cf Tickseed.

Extermination—This weed is easily exterminated by cultiva-
tion. Do not permit seeds to mature.

Sneezeweed (Heleniwm autumnale L.).

Description—A smooth, angular, branching perennial, 1-5 ft.
high; mostly toothed, lanceolate-ovate oblong; heads yellow, ap-
pearing in autumn; involucre of the head or flower consists of
small refiexed scales; ray and disk flowers yellow and fertile; seeds
top-shaped and ribbed; pappus consisting of 5-8 thin, 1-nerved,
chaffy scales. ,

Distribution.—Native to the northern states, particularly from
Missouri and Illinois to Wisconsin and Minnesota; in the Dakotas
as well as in the Rocky mountains, Utah and the northwest.

Extermination——This weed occurs only in low grounds. The
soil should be drained. Then sow to some useful leguminous crop
hike alsike clover. The weed succumbs readily to cultivation.

DESCRIPTIVE MANUAL 355

Fic, 207. Sneezeweed (Helenium autunnale). Common in'low grounds, pas-
tures and along streams.
(Photographed by Colburn.)

Fic. 207-A. Distribution of Sneezeweed

356 WEED FLORA OF IOWA

Fic. 207-B. Sneezeweed (Helenium autumnale).

Fetid Marigold (Dyssodia papposa (Vent.) Hitch.).

Description.—A nearly smooth or somewhat pubescent, branched
annual with strong odor, 6 in.-2 ft. high; leaves opposite, sessile,
pinnately parted, bristly-toothed, with large pellucid glands;
heads many-flowered; disk and ray flowers small, yellow; involucre
with a few scales at the base, one row of scales united to form a
cup; achenes slender, 4-angled, pappus a row of chaffy scales fine-
ly divided into numerous rough bristles.

Distribution.—Common from western Iowa and Minnesota to Il-
linois and to the southwest. Common in western Iowa along right
of ways, streets, barnyards and fields.

Extermination.—This weed is not difficult to destroy by cultiva-
tion. It sometimes occurs in clover seed and alfalfa seed.

DESCRIPTIVE MANUAL 357

Fic. 208. FWetid Marigold (Dyssodia papposa). Pungent smelling herb. Road-
sides, fields, waste places, ete. Especially in western Iowa.
(Photographed by Hart.)

Fig. 208-A. Distribution of Fetid Marigold.

358 WEED FLORA OF IOWA

G Ny EE
VAAL
Za

Fic. 209. Fetid Marigsld (Dyssodia papposa).
(Drawing by Charlotte M. King.)

Yarrow (Achillea millefolium L.).

Description.—A perennial with simple stem 1-214 feet high;
leaves twice-pinnately parted, the divisions linear; 3-5-cleft flowers
in corymbose heads, flat-topped ray flowers usually white, 4-5,
sometimes pink; plant with a somewhat pungent odor.

Distribution—Widely ‘distributed in fields, especially gravelly
knolls and drift soils through the state; particularly common in
northeastern Iowa, found from the Atlantic to the Pacific, also
in Europe and Asia.

Extermination.—The weed is not difficult to destroy by cultiva-
tion. It is not uncommon in clover seed. Practice rotation of
crops; when in the pasture where it is apt to be very common cut

DESCRIPTIVE MANUAL 359

Fig, 210. Yarrow (Achillea millefoliwm). Common in pastures, especially
northwestern Iowa. ‘White flowers.”

Wrcrcd| -

Fie. 210-A. Distribution of Yarrow.

‘360 WEED FLORA OF IOWA

the roots off with a small spade. This will effectually destroy the
plant. In Europe, it is sometimes recommended as a forage plant
but it is of doubtful value.

Mayweed or Dog Fennel (Anthemis cotula L.).

Description—An acrid, branching, strong-scented perennial,
white ray flowers; plants 1-2 feet high; leaves pinnately dissected;
solitary and many-flowered, outer ray flowers pistillate, fertile, or
neutral; disk flowers yellow, small, and tubular; involucre of num-
erous, small, dry scarious scales; achenes small, tuberculate; pap-
pus roughened, none, or merely a minute crown.

Distribution.—This weed is native to Europe; early introduced
in the United States, now common from the Atlantic to the Pacific.
In Iowa more common in northeastern part than westward; es-
pecially abundant in some gardens and along roadsides.

Extermination.—A. weed easily exterminated by cultivation. It
is especially common in clover seed in eastern United States.

Clark and Fletcher recommend as follows: ‘‘Clean up the waste
‘places about the farmyards and seed to permanent grass that will
take full possession of the soil to the exclusion of this and other
weeds. This plant is usually prevalent in gardens fertilized with
manure from city stables.’’

DESCRIPTIVE MANUAL 361

STINKING MAYWEED

tAntne ris

Fie. 211. Mayweed or Dog Fennel (Anthemis cotula). Barnyards, roadsides, etc.
(After Clark and Pletcher.)

862 WEED FLORA OF IOWA

seb
eee
eS D

Cf LA DR

eat

ES
or

Fic. 211-A. Distribution of Mayweed.

Ox-eye Daisy (Chrysanthemum leucanthemum lL. var. prnnatifidum
(Lecoq) Lamotte).

Description.—A perennial herb with erect stem; spatulate, peti-
oled, root leaves, those of the stem partially clasping, all leaves
cut or pinnatifid-toothed; nearly simple stem bearing a large,
many-flowered head with numerous white rays; scales of involucre
with scarious margins, both disk and ray flowers producing
achenes, marked with longitudinal lines; pappus absent.

Distribution—This European weed has long been known as a
troublesome weed in New England and the central states. It is
not abundant in Iowa except in a few places.

Extermination.—This weed is not troublesome as yet in Lowa.
There is much danger, however, that it may be introduced with
clover seed, as it frequently occurs in eastern and European
erown clover seed. Sow only clean clover seed. It succumbs quite
readily to cultivation.

Clark and Fletcher make the following recommendations: “‘Shal-
low plowing of sod in August, with thorough cultivation from time
to time until frost, will suppress it. This pest does not give trouble
on lands worked under a short rotation of crops. Clover for hay
in which this weed is plentiful should be cut early.’’ ;

DESCRIPTIVE MANUAL 363

Fic. 212. Ox-eye Daisy. (Chrysanthemum leucanthemum var. pinnatifidum).
Pastures occasionally.
(After Clark and Fletcher.)

364 WEED FLORA OF IOWA

Fie. 212-A. Distribution of Ox-eye Daisy.

Chemical Composition.—Its chemical composition according to
Me. Bull. Agr. Ex. Sta. 26:6 (1888), is as follows.*

FRESH OR AIR DRY MATERIAL.

A , Nitrogen free
Water | Ash | Protein | Fiber eine Fat
9.63 | 6.85 | Wiecas | 29.00 | 51.72 | 4.36
WATER FREE SUBSTANCE.
| 7.6 | 9.3 | 32.1 | 46.2 | 4.8

Tansy (Tanacetum vulgare L.).

Description.—A bitter, acrid, strongly scented, poisonous herb
or branched perennial 2-4 ft. high; leaves pinnately divided into
linear-pinnatifid divisions, lobes serrate; heads many-flowered, few
ray flowers, disk yellow; marginal flowers fertile; scales of the invo-
luere in several series; receptacle flat or convex, naked; branches
of the style brush-like at the summit; achenes 5-angled or 5- ribbed,
truncate or obtuse; pappus none or a short crown.

Distribution —Common throughout the southern states from the
Atlantic to the Pacific but more common in eastern North America.
Common in many parts of the state of Iowa, especially in some
communities, in gardens and along roadsides.

Extermination.—Hasily exterminated by cultivation.
*Compiled by Jenkins and Winton; Bull. Off. Exp. Sta. 11:78.

Fig, 213.

DESCRIPTIVE MANUAL 365

Tansy (Tanacetum vulgare) Common in old gardens, roadsides, etc.
(Photographed by Colburn.)

Fie. 213-A. Distribution of Tansy. Deena

366 WEED FLORA OF IOWA

Western Mugwort (Artemisia ludoviciana Nutt.).

Description.—A_ branching perennial with inconspicuous flow-
ers; leaves and stems white, woolly; leaves lanceolate, the upper
usually entire, the lower cut-toothed ; heads in narrow panicles, ray
flowers absent; involucre of dry scarious scales; receptacle naked;
flowers small, yellowish; achenes obovoid; no pappus; trichomes
long, simple, cylindrical, tortuous.

Distribution.—This weed is common from Illinois north to Sas-
katchewan, southwest to Texas, and west to Utah. It is quite
widely distributed in the state of Iowa.

Extermination —This weed is easily exterminated by cultivation.
After the crop has been removed the field should be plowed thus
leaving the soil in good condition.

Fic. 214. Western Mugwort, or White Wormwood (Artemisia ludoviciana).
Common in gravelly places, fields and pastures. a, plant hairs.
(Photographed by Colburn, qa. Drawn ,by Charlotte M. King.)

DESCRIPTIVE MANUAL 367

Xeon! | A
yi 1-T SEL Oe
Sie

Fie. 214-A. Distribution of Western Mugwort.

Wormwood (Artemisia biennis Willd.).
Description.—An aromatic, somewhat bitter, smooth annual, or
biennial herb, 1-3 ft. high, with leafy stems and erect branches;

Fie. 215. Biennial Wormwood. (Artemisia biennis). Pungent smelling herb,
fields, woods, etc.
(Photographed by. Colburn.)

368 WEED FLORA OF IOWA

eRe 4
wae aan :
Gate NA

Fic. 215-A. Distribution of Biennial Wormwood.

lower leaves twice pinnately parted, the upper pinnatifid, the
lobes linear or linear-oblong, serrate or cut-toothed ; inconspicuous
flowers; ray flowers absent; heads numerous in short axillary
spikes; bracts of involucre green, scarious, margined.

Distribution—Common in the northern Mississippi valley; now
widely scattered east to Nova Scotia and south to Kentucky. It
occurs in many parts of the state of Iowa.

Extermination—Readily succumbs to cultivation. The plant
should be cut off close to the surface of the ground.

Fireweed (Hrechtites hieractfolia L. Raf.).

Descriplion.—A. coarse, annual weed of rank odor and grooved,
often hairy stem; leaves simple, lanceolate or oblong, acute, cut-
toothed, the upper with auricled base; heads many-flowered; re-
ceptacle naked; flowers tubular and perfect; achenes oblong, tap-
ering; soft, white, capillary bristles.

Distribution —This weed is common in moist woods; in the
north especially in recent clearings which have been burned over,
hence the common name fireweed; also occurs in the Rockies, and
Kansas; common in many parts of Iowa, especially along streams.

Extermination.—EHasily exterminated by cultivation. Plants
should be cut off close to the surface of the ground.

_————————<— ee

DESCRIPTIVE MANUAL 369

Fic. 216. Fireweed (Erechtites hieracifolia). Common in clearings, woodland
pastures.
(Photographed by Colburn.)

Fic. 216-A. Distribution of Fireweed.

24

370 WEED FLORA OF IOWA
Burdock (Arctium lappa L.).

Description.—A coarse, branched biennial 1-3 ft. high; hairy;
leaves large, roundish or heart-shaped, thin, obtuse, entire or den-
tate, floecose, tomentose beneath; petioles deeply furrowed, heads
of purplish or whitish flowers, clustered or somewhat corymbose;
involucre surrounding the flowers lengthened into hooked tips,
glabrous or slightly cottony; trichomes simple, long, twisted.

Distribution.—Burdock has long been known as a troublesome
weed in the northern states and in Europe. Quite common from
New Brunswick to Alabama and the Rocky mountains, the Great
Basin country and on to the Pacific coast. Common in grain
fields and waste places in many parts of the state.

Fig. 217. Burdock (Arctiwn lappa). Common in waste places. A biennial
weed; “seeds’ scattered by animals.
(Photographed by Gardner.)

ett

DESCRIPTIVE MANUAL 371

g
1
. H
oster

sye*
3
4

* . =
2 Ci . .
4 aN 2 5 . . e =
oy ele + Decatur} 2 s ,
UN SE oe ce ea a

Figure 217A Figure 217B
Fig. 217-A. Trichome or plant hair from leaf of Burdock.
(Drawing by Charlotte M. King.)
Fie. 217-B. Distribution of Burdock.

Extermination.—Burdock is easily destroyed. Since it is a
biennial, cut off below the crown during spring or summer. If it
comes up again, cut off once more, or as often as may be necessary.

Dr. Vasey says: ‘‘It may also be killed by being mowed when
the seed has fully formed, and the tops burned.’’

Prof. Shaw says: ‘‘“Farmers who go over their fields twice a
year with the spade will soon have no burdock.’’

Prof. Goff says: ‘‘During the first year of growth the plant is
readily destroyed by pulling out by the roots when the ground is
very wet.’’

The important thing is not to allow it to go to seed; it will then
die if left to itself. But we may always expect an abundance of
the weed as long as it is allowed to grow in waste places. Then
add to this its excellent means of dispersal and no wonder it is con-
stantly coming up in out-of-the-way places.

372 WEED FLORA OF IOWA
Bull Thistle (Cirsiwm lanceolatum (l.) Hill).

Description—Branching biennial, 3-4 ft. high, tomentose, be-
coming dark green and villous or hirsute with age, branchlets
bearing large heads; leaves lanceolate, decurrent on the stem with
prickly wings deeply pinnatifid, the lobes with rigid prickly points,
upper face roughened with short hairs, lower face with a cottony
tomentum ; heads 134-2 in. high; bracts of the involucre lanceolate,
rigid when young, more flexible with age, long-attenuated, prick-
ly, pointed, spreading tips, wholly arachnoid; flower hermaphro-
dite; tube of the corolla 10 lines long; anther tips acute, filaments
pubescent; achenes smooth, 144 in. long; pappus of numerous
plumose bristles.

Dstribution.—Bull thistle is native and indigenous to Europe.
It has long been an inhabitant of the northern states and now ex-
tends across the continent. In Iowa it is abundant in every county,
frequently found in fields and particularly in pastures and wood-
lots.

Externunation.—This weed should be treated like all other bien-
nials. The most important point is to prevent the seeds from
forming. For this purpose the plant should be cut off in early
spring below the surface of the ground. The seeds germinate in
the spring and during the first season produce a flattened mass of
leaves. The second season, a flowering stem shoots up rapidly;
early in August the flowers begin to appear and these are continued
till frost.

The only method of treating is to cut down and remove all the
‘“‘roots’’ as far as it is possible to do so. If this is done frequent-
ly and thoroughly the weed can be exterminated. If the patch is
a small one, cutting off the parts as soon as they appear above the
eround, several times during the season, will certainly destroy
this thistle. In larger patches, plow the ground, harrow and re-
move the thistle, either burn the material, or put into compost
heaps. This should be done five or six times during the season or
as often as occasion may require.

DESCRIPTIVE MANUAL 373

Fic. 218. Bull Thistle (Cirsium lanceolatum). Common in woodland pastures,
roadsides and waste places.
(Photographed by Colburn.)

. .
Kossuth SS

Saas aid) \|X|
Rehee Sisls \
es a

a

Fic. 218-A. Distribution of Bull Thistle.

374 WEED FLORA OF IOWA

Woolly Thistle (Cirsitwm canescens Nutt.).

Description.—Branching perennial, 2-4 ft. high, woolly through-
out, branches bearing single, medium-sized heads; stem angled,
white-woolly ; leaves, radical, 8 in.-1 ft. long, the division usually
2-lobed, prominently ribbed, ending in stout spines; stem leaves,
except the lower, 1-4 inches long, pinnatifid, the upper sessile,
slightly roughened, with a slight cottony down, the lower white-
woolly; heads 114-2 in. high; bracts of the involucre somewhat
arachnoid; lower scales with a broad base, glutinous ridge, and
ending in a minutely serrated spine, inner scales long, attenuated,
tips straw-colored; flowers purple.

Distribution.—This species is distributed from Mason City and
southwestern Minnesota, west to the Rocky mountains. It was
collected by Chas. A. Geyer in 1839 and described by Nuttall. The

Fie. 219. Woolly Thistle (Cirsiwm canescens). Common in western Towa fields
and roadsides.
(Photographed by Quade.)

DESCRIPTIVE MANUAL 375

LER wk

a

is aml Nea es
Be
lam |

Fic. 219-A. Distribution of Woolly Thistle.

writer has seen it very abundant in both Wyoming and Colorado.
The species occurs in. Emmet, Dickinson, Sioux, Plymouth, Wood-
bury, Cerro Gordo, Worth, Ida and Carroll counties in Iowa.

Fig. 220. Woolly Thistle (Cirsium canescens). In pastures and fields of
> northwestern and western Iowa.
(Photographed by Pammel.)

Extermination —Correspondents sending this weed frequently
refer it to Canada thistle. It occurs not only in pastures and mead-

376 WEED FLORA OF IOWA

ows, but also in corn and grain fields. It grows in patches like the
Canada thistle. These patches increase in size from year to year.
It was described as a doubtful perennial by early botanical writers
and so far as I have been able to determine, it is a perennial. It
may be exterminated by thorough cultivation, plowing well and
then following with the cultivator.

Prairie Thistle (Cirsium discolor (Muhl.) Spreng.).

Description.—Tall, branching, leafy biennial, 5-7 ft. high, with
heads larger than in Canada thistle; stem striate, slightly hirsute;
leaves radical, 12-14 in. long, deeply pinnatifid, the divisions fre-
quently divided, prickly-toothed, the upper surface smoothish, and
the lower white ; woolly single heads terminating the branches, with

Fie, 221. Prairie or Wood Thistle (Cirsiwm discolor). Common border of
woods, ete.
(Photographed by Colburn.)

DESCRIPTIVE MANUAL 377

Fig. 221A Figure 221B

Fig, 221-A. Trichomes or plant hairs of wood thistle.
Fic. 221-B. Distribution of Prairie Thistle.

purple flowers; heads 1-11% in. long: bracts of the globose involucre
somewhat suppressed, slightly arachnoid, lower bracts ovate with a
broad base and a weak prickly recurved bristle, slight dorsal ‘gland,
inner linear-lanceolate with a nearly colorless entire appendage;
flowers purple, tube of the corolla 11-12 lines long, lobes of the
corolla terminating in clavate tips; anther tips acute, filaments
pubescent; bristles of pappus plumose; achene 22 lines long,
‘smooth, upper part yellow. ee

Distribution—Common in many portions of Iowa; Marshall,
Johnson, Winnebago, Lee, Winneshiek, Allamakee, Greene, and
Emmet counties; at Keokuk, Muscatine, Ames, Cedar Rapids, Car-
roll; Des Moines, Polk City, Steamboat Rock, Mason: City, Belle
Plaine and Iowa City.

Extermination.—This field thistle should be treated like all other
biennial weeds. The flattened masses in the spring should be cut
off below the ground and none of the plants allowed to go to seed.
We have received numerous inquiries in regard to this weed from
western and northwestern Lowa.

Iowa Thistle (Curstwm towense (Pammel) Fernald).

Description.—Biennial with downy, branching stem; leaves
roughly hairy above but white-woolly beneath, oblong-ovate to nar-
rowly lanceolate, sinuate-toothed, or somewhat pinnatifid, lobes or

378 WEED FLORA OF IOWA

Fig. 222. Iowa Thistle (Cirsium iowense). Common in pastures and meadows.
(Photographed by Colburn.)

Fic. 222-A. Distribution of Iowa Thistle.

DESCRIPTIVE MANUAL 379

teeth with weak prickles; rather large heads; involucre 1-114 in.
long; bracts with broad glandular back, the inner with a some-
what attenuated colorless tip.

Distribution—Common in borders of woods and in fields. From
Iowa to South Dakota and Kansas. In Story, Emmet, Kossuth,
Marshall, Boone, Linn, Clinton, Webster and Carroll counties in
prairie meadows.

Extermination.—This biennial is readily destroyed by cutting
the plants off below the surface of the ground. When left to
flower it dies but in meadows where cut off above the surface of the
ground it acts like a perennial.

Canada Thistle (Cirsium arvense (li.) Scop.).

Description.—Smooth perennial, spreading by roots and root-
stocks, 1-3 ft. high, corymbosely branched at the top; stem smooth ;
leaves lanceolate, sessile, and deeply pinnatifid, lobes and margins
of leaf with spiny teeth; heads small, 34-1 in. high, bracts ap-
pressed, the outer with a broad base, inner narrow, all with an
acute, never spiny, tip; somewhat arachnoid flowers purple, di-
oecious; in staminate plant, flowers exserted with abortive pistils,
in pistillate less so, scarcely exceeding the bracts; tube of the
corolla 6 lines long; stamens with abortive anthers, anther tips
acute, filaments minutely pubescent; young achene pubescent; all
of the bristles of the pappus plumose; trichomes simple, long,
floccose.

Distribution —This European weed is widely distributed in Can-
ada to the Pacific coast; found in Jowa in many counties, more
common in northern counties than in the southern. It is more or
less abundant in Hardin, Pocahontas, Clinton, and Worth coun-
ties, frequently in clover meadows and in pastures.

Extermination.—The Canada thistle can be treated with sodium
arsenite. No other chemicals, so far as our experiments extend,
will entirely destroy this weed. Carbolic acid only partially de-
stroys the roots and the plants shoot up again from below the point
of injury, but by repeating the process the Canada thistle can ulti-
mately be exterminated. A good method of eradicating the weed
is to plow shallow and cultivate frequently during the summer.
The roots of the Canada thistle extend deeply down into the soil,
hence for this reason deep cultivation will be of no avail. After

380 WEED FLORA OF IOWA

Fig, 223. Canada Thistle (Cirsium arvense). Common and widely distributed
in Iowa.
(After Clark and Fletcher.)

DESCRIPTIVE MANUAL 381

Figure 223A Figure 223B

Fic. 223- A. Trichome or plant hair from leaf of Canada Thistle.
-(Drawing by Charlotte M. King.)

Fic. 223-B. Distribution of Canada Thistle.

plowing, the soil should be dragged and the roots exposed to the
sun and removed, when possible. It may be necessary to run
over the field with a hoe to cut off the stray plants which appear.
This method was tried on a patch several years ago and no
Canada thistles have since made their appearance in this place.
Various crops, such as clover and sorghum, are said to be ef-
fective in subduing the thistles.

Of the various chemicals which have been used to exterminate
Canada thistles none are more effective than sodium arsenite. It
is apphed at the rate of 114-2 pounds to 52 gallows of water.

Carbolic acid at the rate of one part to one part water destroys
the root when it comes in contact with the mixture, and for a little
distance beyond. This is not an effective method, as the roots
sprout out from below.

In response to circulars of inquiry sent out by the Iowa Experi-
ment Station, the majority of correspondents recommend shallow
plowing, disking, and harrowing; and continuing cultivation and
hoeing as long as the thistles make their appearance. Some report
successful treatment with galt when scattered thickly about the
thistles, especially if cattle or sheep are given access to it. Some
report success with carbolic acid when it is applied directly to the
stem. Tarred paper in a few cases gave success, as did also the
method where the thistle was covered thickly with straw or ma-
nure. The depth of covering was not, however, given.

382 WEED FLORA OF IOWA

Clark and Fletcher recommend the following treatment:
‘“The chief safeguard against the Canada thistle and all similar
deep-rooted perennials is undoubtedly a regular short rotation. A
three-year rotation, including two cuttings of early red clover for
the first year, followed by a deep fall plowing for hoed crops with
clean cultivation, and a cereal crop for the third year, will sup-
press it.”’

A correspondent in The Prairie Farmer on the resisting quali-
ties of Canada thistle says: ‘‘I have been debating in my mind
and endeavoring to determine whether or not root-stocks or por-
tions thereof have to some extent the hibernating qualities of the
seed. For instance, take two seeds of the cocklebur—one hiber-
nates for one season and the other for two seasons, with growth
always present. Now the question is may not a Canada thistle
with its root-stock or a portion of it lie dormant for a season or
more? If this be true, then some of the best known methods of
extermination are useless.’’

To this Prof. R. A. Moore says: ‘‘In regard to Canada thistle
roots hibernating and retaining their vitality for several years,
will say, that I think your correspondent’s version seems reason-
able, and it is quite conclusive from this fact that the eradication
of the pest is all the more difficult. It seems that many of the
seeds and plants are given this power of remaining dormant when
subjected to adverse conditions. In the lower order of plants,
many of the species of bacteria when subjected to adverse environ-
ments are transformed into resistant spores and will not vegetate
until the conditions are favorable.’’

Wallace’s Farmer says concerning its eradication: ‘‘We
believe if we had a quarter of an acre of Canada thistles
we would let them alone until August, when the thistle will put
forth its utmost efforts to produce seed. While the thistles are in
full blossom we would mow them, rake them up and burn them,
and then plow the ground about eight inches deep, throwing the
furrow flat. Letting them put forth their full strength to produce
seed and thwarting that by mowing and burning would weaken the
roots materially. Then by plowing them under eight inches deep,
if possible, you would attack them at their weakest point.

DESCRIPTIVE MANUAL 383
Knapweed (Centaurea solstitcalis L.).

Description.—Annual erect, branched, cottony stem; lower leaves’
lyrate, deeply pinnatifid, upper leaves, linear, entire or nearly so,
decurrent wings on the stem; outer bracts, with long spreading
spines, those at base few and smaller; flowers yellow, with soft
pappus.

Itc. 224. Knapweed, Star Thistle (Centaurea solstitialis). Im alfalfa fields.
; (Mich. Agr. Exp. Sta.)

384 WEED FLORA OF IOWA

Fic. 224-A., Distribution of Knapweed.

Distribution —Massachusetts to Ontario and Iowa; introduced
with alfalfa seed into other western states.

Extermination.—This annual weed has been introduced largely
with alfalfa seed. Sow clean seed. Use seed coming from the
Rocky mountains or Kansas where the weed is not common. It is
an extremely objectionable weed because of ane spiny heads. It
is easily killed by cultivation.

Chicory or Succory (Cichoriwm intybus L.).

Description—aA branching perennial with deep roots, alternate
leaves; blue flowers, or sometimes pink or purple; basal leaves
spreading on the ground; stem leaves oblong or lanceolate,
partly clasping.

Distribution.—It is common along roadsides in fields and waste
places from New England to Canada to Nebraska, especially com-
mon where chicory has been cultivated; it has become a trouble-
some weed in Wisconsin and Minnesota. It is allied to endive, cul-
tivated as a salad plant.

Extermination.—Chicory is not difficult to destroy where ro-
tation of crops is practiced. Though a perennial, the roots are
easily killed by repeated cultivation.

Clark and Fletcher recommend the following treatment:
‘‘A short rotation of crops will soon suppress it. Chicory is not
often seen in good farming districts except as a wayside weed.
Individual plants may be destroyed by close cutting and applying
salt to the root in hot, dry weather.’’

DESCRIPTIVE MANUAL | 385,

Piate 64 ’

CHIGORY - ay

(Cichoriam infybus- 4)

Fic. 225. Chicory (Cichorium intybus). Im clover and alfalfa fields, some-
times in waste places.
(After Clark and Fletcher.)

25

386 WEED FLORA OF IOWA

WoC a owe
TER SE,
EEE RS, SSR N
VT STS SRS sy ae
UU hkl RSS

Fic. 225-A. Distribution of Chicory.

Dandelion (Taraxacum officinale Weber).
Description.—A smooth, or at first pubescent, biennial or per-
ennial; the many-flowered head borne on a slender hollow scape;
root leaves pinnatifid or runcinate; involucre double, the outer of

Fic. 226. Dandelion (Taraxacum officinale). Long root, sometimes to a depth
of three and one-half feet in the soil.
(Photographed by Gardner.)

DESCRIPTIVE MANUAL tues 387

Fig. 226-A. Distribution of Dandelion.

short scales, the inner of long, linear, erect scales in a single row;
after flowering the inner involucre closes, the fruit is ripened
close to the ground, and when ripe the hollow scape elongates and
the whole involucre is reflexed permitting the wind to scatter the
“seeds ;’’ “‘seeds’’ oblong, long-beaked, the beak being 2 or 3 times
as long as the remainder of the achene, bearing at the end the
pappus. j

Fig. 226-B. A patch of Dandelion in a lawn, early in June.
(Photographed by Charlotte M. King.)

388 WEED FLORA OF IOWA

Distribution—The dandelion is cosmopolitan. It is quite as
common in Europe as in the United States, being common and
abundant at high elevations, as in the Rocky mountains. Found
everywhere in lowa on lawns and pastures.

Fic. 227. Common Dandelion (Taraxacum officinale). A weed common in
lawns, pastures, etc.
(Photographed by Colburn.)

Extermination.—The dandelions are not difficult to exterminate
in cultivated fields but in garden crops it is more difficult to do
so, especially in strawberry beds. As the dandelions are perennial
herbs, seed formation should be prevented. Where they occur in
small patches a spud may be used successfully. Where they are
abundant in lawns it is only necessary to keep the lawn closely
cropped and dig them up with a small spud to prevent seeding.
Blue grass and clover, especially the latter, will crowd them out.
It is rare that dandelions give trouble after the middle of June.

DESCRIPTIVE MANUAL 389

W

RAN 7
Oi?
S NS Ne

ny AR

Fie. 227-A. Common Dandelion (Taraxacum officinale). 1, head; 2, single
flower; 3, achene; 4, receptacle and seed with pappus.

Experiments have been made with herbicides and the one most
commonly used is iron sulphate which is usually applied at the
rate of 100 pounds to one barrel of water. The weed where prop-
erly sprayed will be destroyed, but owing to the fact that the dan-
delion possesses a long perennial root, sometimes 4 feet long, it
will sprout again. The spraying must be kept up until fall.

Chemical Composition.—According to the report of the Bussey
Institution the chemical composition of the dandelion is as follows:

FRESH OR AIR DRY MATERIAL.

. Z Nitrogen free
Water | Ash | Protein | Fiber | Extract Fat
85.54 | 1.99 | 2.81 | 1.52 745 | 0.69
WATER FREE SUBSTANCE.
| 13.8 | 19.4 | 10.5 51.5 4.8

*Bull. 1877. Compiled by Jenkins and Winton; Bull. 11, Off. Exp. Sta., U. S.
Dept. Agr.

390 WEED FLORA OF IOWA

Red-seeded Dandelion (Taraxacum erythrospermum Andyz.).

Description—A perennial weed with long root; leaves deeply
runcinate-pinnatifid or pinnately divided into narrow segments;
heads somewhat smaller than in common dandelion, sulphur yel-
low; involucre glaucous, the inner bracts corniculate, appendaged
at tip; the outer short, spreading or ascending; achene reddish,
tuberculate above.

Distribution.—Red-seeded dandelion is a much more recent in-
troduction than common dandelion. It occurs from Maine to
Kansas. Naturalized from Europe, in similar situations to com-
mon dandelion in Iowa; sometimes less abundant and sometimes
more abundant than the latter.

Extermination—May be exterminated in the same way as the
common dandelion.

Fic. 228. Red-seeded dandelion (Taraxacum erythrospermum). Common in
lawns.
(Photographed by Colburn.)

Clark and Fletcher recommend the following treatment:
‘‘It is important to prevent dandelions from seeding in lands
adjacent to lawns. Though entailing much labor, the most satis-
factory way to deal with them, when deeply rooted in lawns, is to
loosen the soil with a digging fork and pull them up. The use of

DESCRIPTIVE MANUAL 391

the fork may not be necessary in some wet and soft soils. The ap-
plication of kerosene to the crown of the plant, in the centre of
the rosette of leaves, is recommended. Sulphate of ammonia or
sulphate of iron in excess is also recommended. A small table-
spoonful of salt applied in the morning of a hot day, when the soil
is dry, will kill them.

Annual Sow-thistle (Sonchus oleraceus L.).

Description.—Annual, succulent herb with leafy, smooth stems,
and pale yellow flowers in corymbose or umbellate clusters; leaves
of stem dentate, runcinate-pinnatifid, terminal with a large seg-
ment; heads numerous; blossoms in late summer and fall.

Distribution.—This weed is common in fields and waste places
throughout North America, especially in the north. It is common
in Europe and also occurs in Mexico and South America.

Extermination.—Sow thistle is easily exterminated by cultiva-
tion. It can also be exterminated by the use of iron sulphate at the
rate of 100 pounds to a barrel of water; where it is abundant it
may be necessary to make two or three applications.

Clark and Fletcher recommend as follows: ‘‘Prevent them
from seeding in waste places by cleaning them up and seeding them
to permanent, vigorous grasses. This annual weed, with its rela-
tively small, pale yellow flowers, when compared with perennial
species is not difficult to control by ordinary methods of cultivation
and alternation of crops. Sheep, if sufficient in numbers, will pre-
vent sow thistles from seeding in pasture lands.’’

The Iowa Homestead says concerning its eradication: ‘‘We
have seen the sow thistle take complete possession of a soil,
growing so thickly that other crops were entirely choked out. Nec-
essarily the best way to destroy it is to cultivate freely. If it
makes its appearance in stubble ground we would advise plowing
as early as possible after harvest and the cultivation of surface at
intervals during the late summer and fall in order to keep the
thistles below the ground.

392 WEED FLORA OF IOWA

Fic. 229. Common Sow Thistle (Sonchus oleraceus). Waste places.
(After Clark and Fletcher.)

DESCRIPTIVE MANUAL 393

Fic. 229-A. Distribution of Annual Sow Thistle.

Sow Thistle (Sonchus asper (.) Hill). :
Description.—Like the preceding species except that stem leaves
are less divided and more spiny-toothed, with auricles of the

Fic, 230. Sow Thistle (Sonchus aspen), Waste places, yellow flowers and milky
juice.
(Photographed by Colburn.)

394 WEED FLORA OF IOWA

oo
asi aes

Fic. 230-A. Distribution of Sow Thistle.

clasping base rounded; achenes 3-nerved on each side and
margined, smooth.

Distribution—Common with the preceding species, in waste
places.

Extermination—This annual is not difficult to exterminate by
giving thorough cultivation.

Perennial Sow Thistle (Sonchus arvensis L.).

Description.—A perennial with creeping root-stock, and milky
juice; leaves runcinate, pinnatifid and spiny toothed, heart-shaped
base; flowers yellow; peduncle and involucre bristly; achenes ob-
compressed, wrinkled on the ribs.

Distribution—Common from Nova Scotia west to Saskatchewan,
North Dakota, Minnesota, occasional in Iowa to New Jersey and
New England. :

Extermination.—A most difficult weed to exterminate and should
be treated like the Canada thistle. Summer fallow with frequent
cultivation is the only successful method. Clark and Fletcher of
Canada, recommend the following:

“Small patches may be eradicated by digging out the roots as
thoroughly as possible and destroying them. This may have to be
done several times during a season. Great care must be taken not
to distribute pieces of the rootstocks over the fields by harrows or
other implements. To exterminate Perennial Sow Thistle, some
system must be adopted which will prevent the development: of
leaves for a period sufficiently long to kill the roots by smothering

DESCRIPTIVE MANUAL 395

Fic. 231. Perennial Sow Thistle (Sonchus arvensis). Plants with bright yel-
low flowers, milky juice. Not common in Iowa. A difficult weed to exter-
minate.

(Photographed by Colburn.)

Fic. 231-A. Distribution of Perennial Sow Thistle.

396 WEED FLORA OF IOWA

them. When a field is badly infested it requires special treatment
for a season and close’ attention for a number of years. One of
the most effective methods is to plow lightly immediately after
the hay or grain crop is removed and follow with frequent use of
a broad-shared cultivator. Late in the fall plow again, somewhat
deeper. In the spring give frequent cultivation, so as to prevent
the development of any leaves and thus weaken the roots to the
greatest possible extent. About the middle of June or first of
July sow rape in drills at the rate of about 114 lbs. per acre.
Cultivate between the drills as soon as possible and repeat at short
intervals until the rape completely covers the ground. Some hand
hoeing may be necessary to keep all the thistles down. This should
pretty well exterminate the pest but if some plants still remain
when the rape is cut or pastured off, the field may be fall plowed
and put into hoed crop the next season, when special attention can
be given to any small patches that may appear. Buckwheat is
sometimes used instead of rape for a smothering crop.’’

Prickly Lettuce (Lactuca scariola L. var. integrata Gren. & Godr.).

Description.—Tall, erect herbs, glaucous, green, 2-5 ft. high,
simple or branched except the lower part of stem which has stiff
bristles; leaves glaucous, green, smooth except the midrib which
is beset with weak prickles lanceolate to oblong in outline, with
spinulose, denticulate margins, occasionally sinuate-toothed; flow-
ers pale yellow. The leaves of ZL. scariola are pinnatifid and more
prickly ; trichomes multicellular.

Distribution.—Prickly lettuce was introduced into Massachu-
setts about 1863 from Europe. It is quite widely distributed in
northern Africa and Europe and has become frequent throughout
the northern Mississippi valley to the Pacific coast. It is com-
mon everywhere in Iowa particularly along roadsides, highways
and in gardens. The ZL. scartola is becoming more frequent in
Iowa, in Ames, Des Moines, Boone, etc.

Extermination—The weed is easily exterminated from culti-
vated fields and in waste places by cutting off young plants below
the ground. Where the stem is cut off below the surface of the
ground it will give no trouble, but in meadows and lawns where
the plants are cut off above the ground the weed will continually
reappear, producing from 3-6 branches. The following excellent
suggestions are made by L. H. Dewey:

DESCRIPTIVE MANUAL 397

a PRICKLY LETTUCE

fuCR SEGMIGI G fier rica:

A Ge

Fic. 232. Prickly Lettuce (Lactuca scariola var. integrata). Common road-
sides and gardens.
(After Clark and Fletcher.)

398 WEED FLORA OF IOWA

SetMERMneS
e BUYS
ee iM

ase NE Ane

= aa
‘et

Figure 232A Figure 232B

Fic. 232-A. Bristles on Prickly Lettuce (integrata).
(Drawing by Charlotte M. King.)

Fic, 232-B. Distribution of Prickly Lettuce.

‘“Sheep and sometimes cattle will eat the young prickly lettuce,
and in some localities their services have been found very effective
in keeping it down, especially in recently cleared land where culti-
vation is impossible. Repeatedly mowing the plants as they first
begin to blossom will prevent seeding and eventually subdue them.
Thorough cultivation with a hoed crop, by means of which the
seed in the soil may be induced to germinate, will be found most
effective. The plowing should be shallow so as not to bury the
seeds too deep. Under no circumstances should the mature seed-
bearing plants be plowed under, as that would only fill the soil

Fic. 232-C. Distribution of Prickly Lettuce (Lactuca scariola).

DESCRIPTIVE MANUAL 399

with seeds buried at different depths to be brought under condi-
tions favorable for germination at intervals for several years. Ma-
ture plants should be mowed and burned before plowing. The
seed appears as an impurity in clover, millet and the heavier grass
seeds, and the plant is doubtless most frequently introduced by
this means. As the seeds may be carried a long distance by the
wind, the plants must be cleared out of the fence rows, waste land
and roadsides.”’

Clark and Fletcher recommend as follows: ‘‘The seed is
short-lived and if the plant is kept closely cut and prevented
from seeding in waste places for two or three years it will soon
disappear from cultivated areas. Clean waste lands and seed
to permanent vigorous grasses. Ordinary methods of cultiva-
tion will suppress it in the fields.’’

Wild Lettuce (Lactuca canadensis L.).

DescriptionStem leafy, glabrous or nearly so, glaucous; lower
leaves sinuate, pinnatifid, upper entire; heads numerous, in a
rather long, open panicle; flowers yellow.

Distribution.—Nova Scotia to Ontario, Ohio and westward; fre-
quently found in Iowa. ;

Extermination This perennial is not difficult to destroy by
cultivation. .

400 WEED FLORA OF IOWA

Fic. 233. Wild or Canadian Lettuce (Lactuca canadensis). Fields, roadsides
and meadows.
(Photographed by Quade.)

DESCRIPTIVE MANUAL 401

Fic, 233-A. Wild or Canadian Lettuce (Lactuca canadensis). Plant with milky
juice and yellow flowers.
(Photographed by Quade. )

Fic. 233-B. Distribution of Wild Lettuce.

26

402 WEED FLORA OF IOWA

Blue Lettuce (Hactuca pulchella (Pursh.) DC.).

Description.—Perennial plant, deep-rooted, pale or glaucous;
stem simple, about 1 foot high; leaves sessile, oblong or linear-
lanceolate, glabrous, entire, or lower leaves somewhat pinnatifid;
racemose heads large, erect; peduncles with scaly bracts; bracts
of involucre imbricated in 3-4 ranks; flowers blue.

Distribution.—Northern Michigan and Ontario southward; re-
ported from several localities in Iowa.

Extermination.—Prevent from distributing seed by continued
cutting before flowering. If it becomes established in a field, try
thorough summer fallow with deep cultivation so as to check
growth of long rootstocks.

Fig. 234. Blue Lettuce (Lactuca pulchella). Blue flowered lettuce. Plant with
milky juice. Common in western Iowa.
(Photographed by Quade.)

DESCRIPTIVE MANUAL 403

Fic. 234-A. Distribution of Blue Lettuce.
Rushlike Lygodesmia (Lygodesmia juncea (Pursh.) D. Don.).

Description —A tufted, smooth, frequently glaucous perennial a
foot or more high, coming from a thick woody root, with copious

Fic. 235. Lygodesmia or Skeleton Weed (Lygodesmia juncea). A deep rooted
perennial with a yellowish milky juice.
(Photographed by Colburn.)

404 WEED FLORA OF IOWA

Fie. 235-A. Distribution of Lygodesmia.

yellowish juice; lower leaves rigid, linear-lanceolate, small, entire,
the upper scalelike; flowers purple in erect heads; achenes nar-
row-ribbed, pappus light brown. This weed is sometimes called
skeleton weed.

Distribution.—This weed is common from Missouri river to west-
ern Montana and east to St. Croix river in Wisconsin. A some-
what troublesome weed in northwestern Iowa; easily recognized by
the yellowish juice and rushlike stems.

Lixtermination.—This plant produces a long root which enables
the plant to spread rapidly. It also produces a large number of
““seeds.’? Where the weed is common, plough the field after
harvest and disk the plants. It is a good plan to follow up with
a hoe, cutting off the plants.

CHAPTER II.

THE GENERAL CHARACTERS
OF SEEDS

By
L. H. PAMMEL
and

CHARLOTTE M. KING

CHAPTER II.

CYPERACEAE, SEDGE FAMILY.
Sedge (Carex vulpinoidea Mx.).
Achene enclosed by an utricle called the perigynium, hardly 3-

angled, somewhat flattened, tipped by lanceolate 2-toothed beak,
the persistent base of the flower-style; achene flask-shaped, about

Figure 236A

Figure 236B

Fic. 236. Forms of Sedges. a, Hleocharis palustris; b, Carex vulpinoidea.
(After Gray.)

one-sixteenth of an inch in length, light brown; surface incon-
spicuously nerved; whitish, projecting scar.

Spike Rush (Eleocharis palustris R. Br.).

Achenes slightly flattened, somewhat lenticular, with 2 or 3 ob-
tuse angles one-twelfth to one-tenth in. long, brown, smooth, shin-
ing, minutely cross-striated ; seed with persistent tubercle from tip ;
tubercle conical, triangular, constricted; bristles pale, longer than

408 WEED FLORA OF IOWA

Fic. 237. Achenes, “seeds,’’ of common forms of Sedges (Carer).
(After Hillman, Bull. Nevada Agr. Exp. Sta.)

achene; seed may appear with or without tubercle and bristles.
Seed occasionally found in seed of alsike and red clover from wet
erounds.

GRAMINEAH, GRASS FAMILY.

Johnson Grass (Sorghum halepense (li.) Pers.).

Sessile spikelet broadly lanceolate, acute, 4-6 mm.* long, be-
coming dark at maturity ; callus small, obtuse, shortly and sparsely
barbate; first glume coriaceous, slightly pubescent on the flattened
back, 5-7 nerved; second similar, equal to first, with hyaline, ciliate,

Fic. 238. Spikelet of Johnson Grass (Sorghum halepense).
(Drawn by Charlotte M. King.)

inflexed margins; the third glume shorter, membranous, faintly
2-nerved, with ciliate, infolded margins; fourth glume broad, ob-
tuse, shorter than second, 2-lobed at apex, ciliate, awned; awn
10-16 mm. long; palea shorter than glumes, without nerves, ciliate.

Smooth Crab Grass (Digitaria humifusa Pers.).

Spikelets lanceolate or elliptical, one-twelfth in. in length, acut-
ish; glumes usually present, first glume wanting, sometimes rudi-
mentary, 3-nerved; the first and second, hairy on the margins;

*1 mm. = 0.0394 inch, or nearly one-twenty-fifth inch.

THE GHNHRAL CHARACTERS OF SEEDS 409

Fig. 239. Seeds of Smooth Crab Grass (Digitaria humifusa). A and B, spike-
lets; A showing the second glume, B showing the third glume. C, D and #,
florets; D, bearing a portion of the second glume, H, the inner face, showing
the edges of the flowering glume. F, a spikelet of Digitaria filiformis, show-
ing the shorter second glume. G, the natural size of both of these species.

(After Hillman, Bull. Nevada Agr. Exp. Sta.)
the third, 7-nerved; the fourth, dark purplish brown. Occurrence

very frequent in alfalfa clovers and commercial grass seed.

Crab Grass (Digitaria sanguinalis (L.) Scop.).

Spikelets one-seventh in. in length with usually persistent scale-
like glumes, lanceolate, pedicellate; second glume usually ciliate
on margins, short; fourth glume silky-villous along marginal nerves,
5-nerved, color pale. Frequently occurs in red and alsike clover,
as well as in timothy.

FF
a

co fe He
Fig. 240B Figure 240C
Fic. 240. Common Crab Grass (Digitaria sanguinalis). A, an enlarged view
of Crab Grass. B, with small glume attached. C. A, spikelets showing
the second glume, floret, and edges of the third glume. B, the opposite
face, showing the minute first glume and third glume. D and H, the two
faces of the floret. F, seeds, natural size.
(A and B, Drawings by C. M. King; C, after Hillman, Bull. Nevada Agr.
Exp. Sta.)

410 WEED FLORA OF IOWA

Tickle or Hair Grass (Panicum capillare L.).

Spikelets small, ovate or acute, one-fifteenth to one-twelfth in.
long, acuminate-pointed, smooth, shining; sterile glumes usually
absent, when present not shining; first glume 1-3-nerved, obtuse to

Figure 241A Figure 241A Figure 241B

Fic. 241. A. Tickle or Hair Grass (Panicum capillare)., At the left a spikelet
opened, at the right various views. <A, B and C, the outer, inner and edge
views, respectively, of a floret. D and E are views of the spikelet, D
showing the second glume and the first in part, and E the first and third
and the second in part. F, a group showing the natural size of the pre-
ceding. :

B. Sprouting Crab Grass. Various views of spikelets.

(A, at the left, drawn by C. M. King; A, at the right, after Hillman, Bull. Mich.
Agr. Exp. Sta.; B, drawn by C. M. King.)

acute; second and third glumes 5-7-nerved, tips acute; flowering
glume shining, smooth, elliptical, obtuse, or subacute. Often found
in clovers and in timothy.

Sprouting Crab Grass (Panicum proliferum Lam.).

Spikelet lanceolate, ovate, acute, one-tenth in. in length, smooth;
lower glume obtuse, nerveless or 1-3-nerved ; second and third glume
equal, acute, 5-7-nerved ; flowering glume smooth and shining; pedi-
cels scabrous. Rarely found in clover.

Switch Grass (Panicum virgatum L.).

Spikelets ovate, acuminate, 3-5-nerved; flowering glume shorter
than the outer glumes, smooth, shining, minutely striated; with
outer glumes removed, the spikelet resembles a small jassid. Rarely
found in vlovers.

THE GENERAL CHARACTERS OF SEEDS 411

Figure 242A Figure 242B Figure 242C

Fig. 242. A. Switch Grass (Panicum virgatum). a, b, ¢, various views of
spikelet; d, “‘seeds,” natural size.
B. A single spikelet.
C. Millet (Panicum miliaceum).
(A, after Hillman, Bull. Mich. Agr. Exp. Sta.; B and C, drawings by Char-
lotte M. King.)

Millet (Panicum miliaceum L,).

Spikelets acuminate, one-eighth to one-fifth in. long, lower
glume acuminate, 5-7-nerved; third glume subtending the empty
palet, 7-13-nerved ; flowering glume indurated, obtuse, shining, min-
utely cross-striated; the hulled seeds ovoid, yellowish. Found in
clover and alfalfa seed.

Barnyard Grass (Echinochloa crusgallt (l.) Beauv.).

Spikelets with hispid or pubescent nerves; first glume shorter
than the third, awned; second awnless or short-awned; third with
long rigid awn; flowering glume generally ovate; one-tenth to one-
ninth in. longitudinally striate; palet smooth. Not infrequently
found in clovers.

Fic. 243. A. Barnyard Grass (Hehinochloa crusgalli). <A, a floret, back view
of the glume. B, front view of floret, showing the palea. C, edge view of
the same. D, the spikelet, showing the small first glume, the awned third
glume, and the tip of the second. H, a group showing the natural size of
the preceding.

412 WEED FLORA OF IOWA

Fic. 2438. B. Sandbur (Cenchrus tribuloides). a, bur enlarged; b, spine; e and
d, spikelet; e, seed. ;
(After Hillman; A, Bull. Nevada Agr. Exp. Sta., B, Bull. Michigan Agr. Exp.
Sta.)

Sandbur (Cenchrus tribuloides L.).

_ Burs with sharp, straight, pubescent prickles; each bur with
6-20 globose spikelets.

Green Foxtail (Setaria viridis (l.) Beauv.).

““Seeds’’ about one-twelfth in. in length, biconvex, color light
green, or greenish; with flowering glume rounded, slightly granu-

Figure 244A Figure 244B Figure 244C

Fic. 244. A. Green Foxtail (Setaria viridis). A and B, views of the floret ;
A, the back of the glume; B, showing the palea, its shining edges partially
covered by the edges of the glume. OC, a floret covered by the empty
glumes (a spikelet), the figure showing the first and third glumes. D, a
group showing the natural size.

B. Slightly enlarged spikelet.

C. Whorled Millet (Setaria verticillata).

(A, after Hillman, Bull. Nevada Agr. Exp. Sta.; B and C, drawings by Char-

lotte M. King.) :

THE GENERAL CHARACTERS OF SHEDS 413

lar, striate lengthwise and with cross-ridges; palea shining; com-
monly brownish or greenish. In alfalfa, clovers and grass seed.

Whorled Millet (Setaria verticillata (L.) Beauv.).

Spikelets elliptical-ovate, one-twelfth in. long; first glume tri-
angular-ovate, acute or obtuse, 3-nerved; second glume ovate, ob-
tuse, 5-7-nerved; third glume, 5-7-nerved, bears short palet in its
axil; flowering glume about one-fifteenth in. in length, striate, near-
ly smooth; bristles about the flower, 1 or 2, retrorsely scabrous,
one-twelfth to one-third in. long. Found in clover seed.

Yellow Foxtail (Setaria glauca (L.) Beauv.).

““Seeds’” about one-eighth in. in length, very variable; color,
yellowish, brownish, or even pale; perfect flower with flowering
glume plano-convex, partially covering edges of palet; back of

Figure 245A Figure 245B

Fic. 245. Yellow Foxtail or Pigeon Grass (Setaria glauca). A and B, the
outer and inner faces, respectively, of a floret; B, showing the palea. C
and D, the same showing the empty glumes of the spikelet; C, showing the
second glume, and the first and third in part; D, showing the first and
third glumes and the second slightly. E and F, the grain; BH, the convex,
embryo-bearing face; F, the plane face. G, a group showing the natural
size.

B. Slightly enlarged spikelet.

(A, after Hillman, Nevada Agr. Hxp. Sta. Bull.; B, drawing by Charlotte M.

King.)

flowering glume with prominent transverse branching ridges; flow-
ering glume minutely granular. In alfalfa, clovers and grass seed.

Mexican Dropseed (Muhlenbergia mexicana (l.) Trin.).

Spikelet about one-twelfth in. long, on very short pedicel; empty
glumes nearly equal, acuminate; flowering glume lanceolate, 3-
nerved, scabrous on keel, pilose near base; sterile and flowering

414 WEED FLORA OF IOWA

glumes marked by dark, longitudinal lines; seed brown. about one-
twelfth in. in length, marked at embryo by darker elliptical area.
Occurs in alfalfa and the clovers.

Marsh Muhlenberg (Muhlenbergia racemosa (Mx.) B. 8S. P.).

Spikelets one-sixth to one-quarter in. long; lower glume acumi-
nate-pointed ; flowering glume acute, densely bearded at base, min-
utely pubescent and marked by black lines; seed slender, cylindri-

¥

Fig. 246A Figure 246B Fig. 246C

Fic. 246..: Dropseed Grasses. A. Seed of Mexican Dropseed Grass (Muhlen-
bergia mexicana). B. Spikelet of Marsh Muhlenberg (M. racemosa). C.
Nimble Will (MU. schreberi). 5

(Drawings by Charlotte M. King.)

cal, brown, with black area at one end. Found in timothy and
clover seed.

Nimble Will (Muhlenbergia schrebert J. F. Gmel.).

Spikelet one-twelfth in. in length, as long as or longer than pedi-
cel; empty glume minute; lower sometimes absent; flowering glume
lanceolate, slender, awned, scabrous on nerves. Found in clover
seed.

Timothy (Phlewm pratense L.).

Flowering glume or larger scale marked by several veins, truncate
at top, shorter scale or palet also prominent; seed usually with
flowering glume; one-sixteenth to one-twelfth in. long; color light

THE GENERAL CHARACTERS OF SEEDS 415

Fig. 247A Figure 247B

Fie. 247. A. Timothy (Phlewm pratense). Hulled and unhulled seed. B. Red
Top (Agrostis alba).
(A, drawing by Charlotte M. King; B, after Hillman, U. S Dept. Agr.)

gray; seeds somewhat transparent with darker elongated area at
lower end, marking the location of the embryo.

Red Top (Agrostis alba L.).

Spikelet one-twelfth to one-eighth in. long, empty glumes
lanceolate, acute; the first scabrous on the keel; the second a little
shorter, and smooth or scabrous near the apex; flowering glume a
little shorter than the empty ones, obtuse or truncate; palet one-
half to three-quarters as long as glume; rachilla frequently present
in seed, roughened ; fruit brownish, ovate.

Wild Oats (Avena fatua L.).

Fruit spindle shape, and of a light yellow color on the tip, bal-
ance darker yellow to blackish brown; bears one long geniculate
awn with lower end twisted; basal scar oval, sloping, with a bunch
of soft hairs just above; size 15 mm.

416 FLORA OF IOWA

pe ~ ese “4 -
a: = : 2

WW. £9. . 9s ne ET
Figure 248A

Fie. 248. Wild Oats (Avena fatua). a, spikelet; b, floret; c, natural size.
(A, after Hillman, Bull. Nev. Agr. Hxp. Sta.; B, Bull. Mich. Agr. Exp. Sta.)

Figure 248B

Crowfoot or Goose Grass (Eleusine indica Gaertn.).

Spikelets closely imbricated, 114-2 lines (334-5 mm.) long, 3-6-
flowered ; glumes obtuse, the first small, 1-nerved, the second larger,

with flowering glumes 3-5-nerved; seeds rugose, enclosed within a
thin, loose pericarp. |

Figure 249A

Figure 249B Figure 249C
A. Crowfoot or Goose Grass (Hlewsine indica).

views of seed. :
B. Tufted Hragrostis (Eragrostis pilosa), a, spikelet; b. fruit.

Fig. 249. a, florets; b, c, d,

C. Candy Grass (Hragrostis megastachya).

A. Seeds enlarged. B. Seeds
natural size.

THE GENERAL CHARACTERS OF SEEDS 417

Candy Grass (Eragrostis megastachya (Koeler) Link.).

Spikelets ovate to linear, many-flowered, one-sixth to two-thirds
in. long; empty glumes nearly equal, ovate-lanceolate, one-twelfth
in. long, prominently nerved, scabrous on keel; palet cilate on
keel; seed small, ovoid to elliptical, one-thirty-second in. in length,
color brown. Found in commercial grass seed and alsike clover.

Southern Spear Grass (Eragrostis pilosa (.) Beauv.).

Spikelet narrow, lanceolate, 3-15-flowered, equaling or exceeding
the capillary pedicels, one-sixth to five-twelfths in. long; empty
glume ovate, acute, scabrous on keel; flowering glume broadly ovate,
obtuse, 3-nerved, scabrous on keel, one-seventh in. in length; palet
ciliate on keel; seeds small, elliptical or ovoid; one-twenty-eighth in. |
in length. Found in commercial grass seed.

Orchard Grass (Dactylis glomerata L.).

Spikelets compressed, 3-5-flowered, in crowded, 1-sided clusters;
flowering glumes lanceolate, acute or awn-pointed, one-sixth to one-
quarter in. in length, ciliate on keel, and otherwise minutely pu-

Fic. 250. Orchard Grass (Dactylis glomerata).
(After Hillman. U. S. Dept. Agr.)

bescent; callus at base; palet serrate on margin near upper end and
minutely pubescent.
27

418 WEED. FLORA OF IOWA

Wire Grass (Poa compressa L.).

Spikelets lanceolate, 5-9-flowered, one-sixth to one-quarter in. in
length, flowering glumes about one-seventh in. in length, obscurely
5-nerved ; marginal teeth of palet continue to extreme apex. Found
with seed of Kentucky blue grass and other commercial grass seed.

Figure 251A Figure 251B

‘Fic. 251. A. Wire Grass (Poa compressa). a, b, two views of seed; ¢,
natural size; d, upper portion of palet showing marginal spines. B. Ken-
tucky Blue Grass (Poa pratensis). a, b, two views of seed; ec, natural
size; d, upper part of palet showing marginal spines.

(Hillman, Bull. Mich. Agr. Exp. Sta.)

Kentucky Blue Grass (Poa pratensis L.).

Spikelet 3-5-flowered, one-sixth in. long, on short scabrous pedi-
cels; empty glumes slightly unequal, lower nearly lanceolate, 1-
nerved, upper glume broader, 3-nerved; flowering glume ovate,
scarious towards the apex, base cobwebby, rachilla slender; palet
with marginal teeth disappearing short of the apex. Found oe-
easionally in fescue grass seed and the commercial grass seed.

Meadow Fescue (Festuca elatior L.).

Spikelet lanceolate, 5-10-flowered ; empty glume lanceolate, acute,
one-quarter in. long, smooth, faintly striate; indistinctly 5-nerved;
rachilla slender. Occasionally found in brome grass and rye grass
seeds.

Fic. 252. Meadow Fescue (Festuca elatior).
(Drawing by Ada Hayden.)

THE GENERAL CHARACTERS OF SHEDS 419

Soft Chess (Bromus hordeaceus L.).

Flowering spikelet 7-9 mm. in length, obtuse and awned; awns
6-8 mm. in length; roughened; glume with 3 nerves on each side;
glume bearing numerous hairs upon the surface; caryopsis 5 mm.
long, 2 mm. wide, light brown, scar at base, extending one-third
length of seed.

Figure 253B

Fie. 253. A. Soft Chess (Bromus hordeaceus). a, b, views of enlarged seed ;
ec, natural size.
B. Chess (Bromus secalinus). a, b, ec, d, views of seed, enlarged; e, natural
size.
(After Hillman.)

Smooth Brome or Hungarian Brome Grass (Bromus inermis Leyss.).

Empty glumes unequal; flowering glumes awnless or short-
awned, with broad scarious margin at obtuse or emarginate apex; |
veins of flowering glume conspicuous, roughened; veins of palet
roughened; seed flattened, boat-shaped, one-third in. in length,
one-twelfth in. in width.

420 WEED FLORA OF IOWA

Figure 254B Figure 254A

Fic. 254. A. Smooth Brome (Bromus inermis). B. Awned Brome (Bromus
tectorum).
(A, after Hillman; B, drawn by Ada Hayden.)

Awned Brome Grass (Bromus tectorum L.).

Spikelet with unequal, acuminate-pointed, hirsute empty glumes,
and rough or hirsute flowering glumes 8-12 mm. long; awn 12-16
mm. long.

Chess (Bromus secalinus L.).

Spikelets tinged, 6-12-flowered, pendulous in fruit, one-twelfth
to two-fifths in. long; empty glume oblong-lanceolate; flowering
glume ovate-oblong, obscurely 7-nerved, nearly awnless, or short-
awned from the back of apex; pubescent along margins and toward
the apex; palet obtuse, strongly nerved;: toothed or fringed with
distant bristles; seed brownish. Found in oats and other small
erain.

Perennial Rye Grass (Loliwm perenne L.).

Spikelets about one-half in. in length, 5-12-flowered; empty
glume much shorter than the spikelet; flowering glume obscurely
uerved, obtuse, cuspidate, or very short awn-pointed, bearing callus
at base; palet granulate; serrulate on margin.

THE GENERAL CHARACTERS OF SHEDS 421

\\
\\ |
\\ ¥
iy

Figure 255A Fig. 2554

Figure 255B Fig. 255B

Wig. 255. A. Perennial Rye Grass (Loliwm perenne). B. Italian Rye-grass
(Lolium italicum). =
(A, after Hillman; B, drawn by C. M. King.)

Italian Rye Grass (Lolium italicum A.).

Spikelets two-fifths to three-fifths in. long, 6-15-flowered ; flower-
ing glume scabrous near the summit, awned; awn slender, about
length of glume; margin of palet serrate.

Quack Grass (Agropyron repens (L.) Beauv.).

Spikelets 4-8-flowered; empty glumes 5-7-nerved, obtuse or
notched, acute or acuminate; flowering glume awned near apex;
two-fifths in. in length; 5-7-nerved above the middle, finely rough-

422 WEED FLORA OF IOWA

Figure 256A

Figure 256B

Figure 256C

Fie. 256. A and B. Quack Grass (Agropyron repens). showing various forms.
C. Slender Wheat Grass (Agropyron tenerum).

THE GENERAL CHARACTERS OF SEEDS 423

Figure 256D

Fic. 256. D. Western Wheat Grass (Agropyron snvithii) ; a, large spikelet ;
b and d, small spikelet; c, edge view of spikelet; e, empty glumes; f, empty
glume attached to axis of spikelet.

‘(After Hillman. A, Cir. U. S. Dept. Agr.; B. Bull. Mich. Agr. Exp. Sta.; C.
Cir We S:Dept-Acr. =D; Cir Us iS.) Dept. Ser),

ened, granular-serrate on margins, finely pubescent at apex;
rachilla prominent, hairy, minutely roughened. Occasionally oe-
eurs in clovers.

Western Wheat Grass (Agropyron smithi Rydb.).

Fruit similar in shape and size to A. repens, but the broadest
portion nearer the tip, giving it more of the characteristic outline
of brome grass; tip generally awned, surface finely pubescent;
toothing on edge of palea seems finer than in A. repens.

Poison Darnel (Lolium darnnarninnna).

Flowering glume about three-tenths in. long, awned or awnless,
smooth, obscurely nerved; margins folded in over the palet; tur-
eid; shorter than in Lolium perenne.

Wild Barley (Hordeum jubatum L.).

Spikes narrow, 1-3 in. or more long; empty glumes rigid; the 4
internal ones of each group dilated above the base, those of central
sublaneeolate, all awn-pointed; outer glumes of lateral spikelets
setaceous; flowering glume of central spikelet awned; florets of
lateral spikelets awnless.

424 WEED FLORA OF IOWA

Figure 257A Figure 257B Figure 257C

Fic. 257. A. Seed of Darnel (Loliwm temulentum). a, b, with awns enlarged,
e, natural size.

B. Wild Barley (Hordeum jubatwm.) C. Little Barley (Hordeum pusillum).

(A, after Winton; B, after Hillman, Bull. Mich. Agr. Exp. Sta; C, drawn by
C. M. King.) :

Little Barley (Hordeum pusillum Nutt.).

Spikelet 1-3-flowered; empty glumes rigid, the 4 internal ones
of each group dilated above the base, those of the central spikelet
sublanceolate, all awn-pointed; outer glumes of the imperfect lat-
eral spikelets setaceous; flowering glume of the central spikelet
awned, awn equaling those of the empty glumes; florets of the
lateral spikelets awnless, or nearly so.

URTICACEAE, NETTLE FAMILY.

Hemp (Cannabis sata L.).

Achene ovoid, brown with more or less hght markings, 4 mm.
in diameter; surface smooth.

THE GENERAL CHARACTERS OF SHEDS 425

Figure 258A

Figure 258B

Fic. 258. A. Hemp (Cannabis sativa). I. Seed in envelope. II. Seed without
envelope. III. Cross section of seed. F. pericarp; S. testa; E. endosperm.
B. Nettle (Urtica gracilis). a, seed in envelope; b, seed enlarged; d, natura!
size.

(A, after Winton; B, after Hillman, Bull. Mich. Agr. Exp. Sta.)

Nettle (Urtica gracilis Ait.).

The fruit enclosed in membranous calyx; seed pale straw-color,
1 mm. long, flattened, ovate, slightly pointed toward the ends,
smooth; point of attachment at broader end.

POLYGONACEAE, BUCKWHEAT FAMILY.

Sour Dock (Rumex acetosa L.).

Inner sepals of calyx in fruit, with wings; achene ‘convex be-
tween angles; one-twelfth in. in length, variable, smooth, shining;
dark reddish brown. Probably occurs in European grown clover
seed.

Sheep Sorrel (Rumex acetosella L.).

Calyx usually persistent, not wing-margined in fruit, roughened,
with prominent veins; closely fitting achene, elliptical or ovate

426 : WEED FLORA OF IOWA

Figure 259A

Figure 259B

Fic. 259. A. Sour Dock (Rumex acetosa). A, various ‘achenes. 3B, diagram

of the calyx. C, achenes and calyx, natural size.

B. Sheep Sorrel (Rwmex acetosella). A, seeds bearing the calyx segments.
B, one having the segments partially broken away. C, achenes from which
the calyx is removed. D, seeds, natural size.

(After Hillman, Bull. Ney. Agr. Exp. Sta.)

with blunt angles, one-twenty-fourth to one-twentieth in. in length;
eolor of fruit grayish to brownish. Common in red, white and
alsike clover.

Curled Dock (Rumez crispus L.).

Perianth frequently persistent, consisting of thin veined lobes
-of the calyx, winged in fruit; wings cordate or notched at base;

Figure 260

Fic. 260. Curled Dock (Rumeax crispus). A, views of achenes. B, a cross-
sectional view of the same. C, diagram of the calyx. D, achenes and
calyces, natural size. E, a shrunken achene.

(After Hillman, Bull. Nev. Agr. Exp. Sta.)

THH GENERAL CHARACTERS OF SHEDS 427

margins entire, each with tubercle on the back; color brown;
achene triangular, elliptical, with pointed apex; one-twelfth to one-
eighth in. in length; color brown; surface smooth, shining; mar-
gins minutely roughened. .

Tall Dock (Rumex altissimus Wood).

Usually but one wing of fruiting calyx bearing tubercle; pedicel
as long as wings; perianth segments veined; margins nearly en-
tire; achene triangular, widened at the base; one-sixteenth to one-
twelfth in. in length; scar prominent.

Fig. 261A

Figure 2610 Figure 261D

Fic. 261. A and B, Tall Dock (Rumeax altissinus). C and D, Broad-leaved
Dock (Rumex obtusifolius). C, tubercle and calyx.
(A, drawn by L. R. Collins; B and C, drawn by Ada Hayden; D, after Hill-
man, Bull. Nev. Agr. Exp. Sta.)

Broad-leaved Dock (Rumex obtusifolius L.).

Wings of the fruit small, only 1-tubercled; margins of wings
‘deeply toothed, backs rugose; fruit three-sixteenths in. long;
achenes convex between angles, one-twelfth to one-eighth in. in
length; conspicuous scar at base.

428 WEED FLORA OF IOWA

Water Smartweed (Polygonum acre HBK.).

Achenes oblong, thick, generally 3-angled, somewhat lenticular,
one-tenth to one-eighth in. in length, smooth, finely reticulated;
color dull; base of perianth adhering.

Dooryard Knotweed (Polygonum aviculare L.).

Achenes 3-angled, ovoid, acute, sides deeply concave, one-eighth to
one-seventh in. in length; color light to dark and reddish brown;
surface finely granulated and striated lengthwise.

A
Figure 262B

Figure 2620 Figure 262D

Fic. 262. A. Water Smartweed (Polygonum acre).

B. Dooryard Knotweed (Polygonum aviculare). A, group of seeds (achenes)
showing the usual forms; that at the right is one of the smooth, light
colored specimens; B, a group showing the natural size; C, a cross. section
showing the relative positions of embryo and endosperm.

C. and D. Prince’s Feather (Polygonwm orientale).

(A and D, drawn by C. M. King; C, drawn by Ada Hayden; B, after Hillman.)

Prince’s Feather (Polygonum orientale L.).

Achenes usually orbicular, flattened, with prominent remnant of
style, one-ninth in. in length, finely reticulated; color dull brown-
ish to black; base with large sear; remnant of colored calyx at
base.

THE GENERAL CHARACTERS OF SHEDS 429

Black Bindweed (Polygonum convolvulus L.).

Achenes large, prominently 3-angled, ovoid-pyramidal, one-
eighth to one-sixteenth in. in length; surface dull, with minute
striae; color blackish; perianth usually removed, when present
straw-colored.

Figure 263A Figure 263B

Fic. 263. A. Black Bindweed (Polygonum convolvulus). A and B, views of
two seeds, the latter bearing a portion of the perianth about the base. C,
a view of an entire perianth covering a seed. D, a group showing the
natural size.
B. Erect Knotweed (Polygonum erectum).
i (After Hillman, Bull. Mich. Agr. Exp. Sta.)

Erect Knotweed (Polygonum erectum I.).

Achenes 3-angled, ovoid, less deeply concave between the angles
than in preceding (P. aviculare) ; one-ninth to one-tenth in. in
length; dull, minutely reticulated.

Figure 264A Fig 264B

Hic. 264. A. Water Pepper (Polygonwm hydropiper). Seeds enlarged and
natural size; the embryo at C.
B. Mild Water Pepper (Polygonum hydropiperoides).
(A, after Hillman; B, drawing by Ada Hayden.)

430 WEED FLORA OF IOWA

Water Pepper. (Polygonum hydropiper L.).

Achene lenticular, triangular; form broadly oblong or ovoid,
shghtly gibbous; one-tenth in. in length; dull, color light.

Mild Water Pepper (Polygonum hydropiperoides Mx.).

Achenes 3-angled, ovoid, angles between flattened, sides rounded,
one-eighth to one-tenth in. in length; smooth, shining.

Slender Pink Smartweed (Polygonum lapathifolium L.).

Achenes ovoid-oblong, lenticular, edges slightly angled along the
center, with a prominent remnant of the style at upper end, one-

Figure 265A Figure 265B

Fig. 265. A. Slender Pink Smartweed (Polygonum lapathifolium). <A, a side
view of an achene bearing a part of the perianth at the base, enlarged. B,
a group showing the natural size, one shown edgewise. C, a cross section
of an achene.

B. Lady’s Thumb (Polygonum persicaria). A, B and C, side views of com-
mon forms of achenes; C, a three-angled specimen. D, one covered by the
perianth (reduced from the size of A, B and C). E, a group showing the
natural size. F, a cross section of an achene.

(After Hillman, Bull. Nev. Agr. Exp. Sta.)

twelfth to one-tenth in. long; color light brown to dark brown,
shining; base of achene with remnant of perianth adhering.

Pennsylvania Smartweed (Polygonum pennsylvanicum L.).

Achenes orbicular, usually broader than long, with edges as in
P. lapathifolium, remnant of style short, one-seventh to one-sixth
in. long; color blackish, dull, base of achene with perianth ad-
hering.

Lady’s Thumb (Polygonum persicaria L.).

Achenes broadly ovate, lenticular, often somewhat 3-angled at
base, one-eleventh in. in length; surface smooth, shining; color
dark; remnant of perianth present at base.

THE GHNERAL CHARACTERS OF SEEDS 431

A *, ; B
Fic. 266. Pennsylvania Smartweed (Polygonum pennsylvanicum). <A, a side
view of a seed (achene). B, one surrounded by the calyx; the opposite side
has two segments between those on the edges. C, a cross section of a
seed. D, seeds, natural size,
(After Hillman, Bull. Nev. Agr. Exp. Sta.)

Bushy Knotweed (Polygonum ramosissimum Mx.).

Achenes sharply 3-angled, sides less deeply concave than in
P. aviculare, one-eighth in. in length; color blackish, dull; calyx
greenish, light straw-colored in dried specimens.

Figure 267A : Figure 267B Figure 267C Figure 267C

Fic. 267. A. Pennsylvania Smartweed (Polygonum pennsylvanicum). B. Tan-
weed (Polygonum muhlenbergtui). C. Bushy Knotweed (Polygonum ramos-
issimum ).

(A and B, drawings by Charlotte M. King; C, drawings by L. R. Collins.)

CHENOPODIACHAH, GOOSEFOOT FAMILY.
Cycloloma (Cycloloma atriplicifolium (Spreng.) Coult.).

Fruit enclosed by the calyx, lower surface prominently rayed,
upper surface depressed, wing-margined, one-tenth to one-eighth in.
in diameter; seed nearly spherical, somewhat flattened, one-twelfth
in. in diameter, blackish; scar whitish; embryo slender, forming a
ring about the endosperm.

Fic. 268. Cycloloma (Cycloloma atriplicifolium). a, b, seed in envelope; c,
d, enlarged views; e, seeds, natural size; f, cross section.
(After Hillman, Bull. Mich. Agr. Exp. Sta.)

432 WEED FLORA OF IOWA

Lamb’s Quarters (Chenopodium album L.).

Seeds one-twentieth in. in diameter, often surrounded by thin
glandular utricle which varies from grayish to straw-color; seed
dark brown, shining, firmly attached to pericarp, edge rounded,
lower, convex with a curved groove; seed somewhat irregular in
shape; some seeds also surrounded by the pericarp and star-shaped
calyx. In seed of small grains, clover and grasses.

Figure 269A

Figure 269C

Fic. 269. A. Lamb’s Quarters (Chenopodium albwm). a to b, different views of
seed; d, g, f, seed with utricle; i, calyx attached.

B. Maple-leaved Goosefoot (Chenopodium hybridum). a, seed in envelope; b,
Gy. general view of seed; d, cross section; e, natural size.

C. Western Lamb’s Quarters (Chenopodium murale). A, B and C, views of
seed; D, the natural size.

(After Hillman, A and B, Bull. Mich. Agr. Exp. Sta.; C. Bull. Nev. Exp. Sta.)

Maple-leaved Goosefoot (Chenopodium hybridum L.).

Seeds dark grayish black, circular, 2.5-3 mm. in diameter, flat-
tened double-convex, with distinct margin, slightly indented by a
notch; scar on middle of one face; seed shining, black, when en-
velope is entirely removed.

Spinach (Spinacia oleracea .).

Fruit broadly ovate, one-sixth in. in length, size variable; utricle
unarmed, wrinkled, sometimes tuberculate, straw-colored; achene
closely enveloped by utricle; sear elevated.

THE GENHRAL CHARACTERS OF SHEDS 433

Figure 270A Figure 270B

Fic. 270. A. Spinach (Spinacia oleracea).

B. Orach (Atriplex patula var. hastata). a, b, ec, different views of seed in
envelope; d, e, f, views of seeds.

(A, drawing by Charlotte M. King; B, after Hillman, Bull. Mich. Agr. Exp. Sta.)

Orach (Atriplex patula var. hastata (.) Gray).

Fruiting bracts ovate-trianeular, entire toothed, often muricate
en the back, united to near the middle; seed jet black, shining,
nearly circular, edge bluntly rounded, bearing a notch; a groove
leads from protuberance on the margin part way to center of face.

Russian Thistle (Salsola kali var. tenwifolia G. F. W. Mey.).

Calyx persistent, 5-parted, membranaceous, enclosing the flat-
tened utricle by a broad, flat, membranaceous wing; seed conical,

Figure 271A Figure 271B

Fie. 271. A. Russian Thistle (Salsola kali var. tenwifolia), a, seed in envelope;
b, d, e, views of seed enlarged; c, natural Size.
B. Kochia or Mexican Fireweed (Kochia scoparia).
(A, after Hillman, Bull. Mich. Agr. Exp. Sta.; B, drawing by Miss King.;

upper end truncate, with a depression one-eighteenth in. in
diameter, brownish; seed without endosperm, embryo coiled in a

spiral; cotyledons slender.
28

434 WEED FLORA OF IOWA
AMARANTHACEAE, AMARANTH FAMILY.
Spreading Amaranth (Amaranthus blitoides Wats.).

Seeds lenticular or round to broadly egg-shaped, one-sixth in. in.
diameter, both sides convex with distinct margin, glossy, black;

B

Fig. 272. Spreading Amaranth (Amaranthus blitoides). A, seeds. B, a broken
specimen. C, an edge view. D, the natural size.
(After Hillman, Bull. Nev. Agr. Exp. Sta.)

seeds borne in ovoid-oblong utricle, 2-3-beaked by the persistent
style. Reported in western alfalfa seed.

Tumbleweed (Amaranthus graecizans L.).

Seeds lenticular or roundish, one-twenty-fourth in. in diameter,
glossy black, much like the preceding but smaller. In grasses and
lawn mixtures.

Fic. 273. Tumbleweed (Amaranthus graecizans). A, seeds. B, a broken one.
C, the natural size.
(After Hillman, Bull. Nev. Agr. Exp. Sta.)

Rough Pigweed (Amaranthus retroflexus L.).

Seeds from one-eighteenth to one-twentieth in. in length; oval,
spherical or nearly spherical, both sides convex with a continuous
ring on the margin; scar small; smooth, black, shining; seeds much
like A. blitoides but somewhat smaller. In seeds of red clover,
alsike, and timothy.

THH GENERAL CHARACTERS OF SEEDS 435

- Wie. 274. Rough Pigweed (Amaranthus retroflerus). A, seeds; B, one having
the seed-coat broken; C, the natural size.
(After Hillman, Bull. Ney. Agr. Exp. Sta.)

Water Hemp (Acnida tuberculata Mogq.).

Seeds erect, lens-shaped, one-fifteenth in. in diameter, smooth,
shining, black, 2-5 remnants of stigmas, sometimes with the at-

Fie. 275. Water Hemp (Acnida tuberculata). a, b, c, different views of seed;
d, cross section; e, in seed envelope; f, natural size.
(After Hillman, Bull. Mich. Agr. Exp. Sta.)

tached calyx and mucronate bracts; utricle longer than bracts;
circumscissile, not angled. In seed of clover and alsike.

CARYOPHYLLACHAH, PINK FAMILY. -
Chickweed (Stellaria media (.) Cyrill.).

Kidney-shaped, broadly egg-shaped, to wedge-shaped, one-
twentieth in. in length, finely and closely tubercled; color grayish

Fie. 276. Chickweed (Stellaria media). A, seeds, side view. B, one shown
in edge view. C, a sectional view showing the embryo and endosperm.
D, group showing the natural size.
(After Hillman, Bull. Nev. Agr. Exp. Sta.)

to light brown; scar marked by a longitudinal groove at basal end.
Occasionally found in clover.

436 WEED FLORA OF IOWA
Corn Cockle (Agrostemma githago L.).

Seeds large, angular, broadly wedge-shaped, one-eighth in. in
length; tubercles prominent, lines of tubercles beginning at basal
end of seed; color brown to black; size of seed variable; according

Fig. 277. Corn Cockle (Agrostemma githago), a, seed enlarged; b, seed in
cross section; ec, natural size.
(After Hillman, Bull. Ney. Agr. Exp. Sta.)

to Dewey the larger ones hard to screen out. Most commonly found
in wheat; seed has poisonous properties. ‘‘Pest in grain fields.’”
Found in wheat and in chicken feed.

Bladder Campion (Silene latifolia (Mill.) Brit. & Rendle).

Seed kidney-shaped, more nearly spherical than in Silene nocti-
flora, one-fifteenth in. in length; shape of seed more nearly or-
bicular than in S. noctiflora. Found in some clovers.

Pastas:
ee re 2 ®
OR y)
SN f @ 9
c &
A ae
e
Fic. 278. Bladder Campion (Silene latifolia). A, common forms of seeds,

side view. B, edge view of a seed, showing the scar-cavity. CC, the nat-
ural size of the seeds.
(After Hillman, Bull. Nev. Agr. Exp. Sta.)

Forked Catchfly (Silene dichotoma Ehrb.).

General shape of seed roundish triangular, somewhat flattened,
about 1.5 mm. in breadth; color dull reddish brown; 5-7 rows of
tubercles on each side in curved rows following the rounding out-
line of the shape of the seed; scar on the straight side of seed.

THE GENERAL CHARACTERS OF SHEDS 437

VANES
Uhr

Fizure 279A

Figure 279B

Fic. 279. A. Forked Catchfly (Silene dichotoma). a, seed enlarged; b, nat-
ural size.

B. Night-flowering Catchfly (Silene noctiflora). A, side view of a seed; B,
edge view of the same, showing the scar-cavity. C, a longitudinal section
of a seed, showing the embryo curved about the endosperm. D, the nat-
ural size of the seeds.

(After Hillman; A, Bull. Mich. Agr. Exp. Sta., B, Bull. Nev. Agr. Exp. Sta.)

Night-flowering Catchfly (Silene noctiflora L.).

Seeds kidney-shaped, thick, with rounded edges, one-fifteenth to
one-tenth in. in length; surface roughened by peculiar tubercles; on
shorter side a black elevated scar; immature seeds red. Found in
clover and grass seed.

Figure 280A Figure 280B

Fic. 280. A. Evening Catchfly (Silene vesrertina).
B. Evening Catchfly (Lychnis alba).
(Drawings by L. R. Collins and Ada Hayden.)

Evening Catchfly (Silene vespertina Sibth.).

Seed smaller than that of S. noctiflora, which resembles it, one-
fifteenth of an in. in length; ash-colored. Found in alfalfa and
clover seed.

438 WEED FLORA OF IOWA

Cowherb (Saponaria vaccaria L.).

Seed nearly spherical, one-twelfth in. in length, minutely tu-
bercled; color black; immature seeds reddish; scar whitish, in de-
pression. Occurs in wheat and in red clover.

®e

Fic. 281. Cowherb (Saponaria vaccaria). A, different views of the seeds;
the one at the left and the lower one show the sear; the light spots show
the minute surface-projections. B and C, parts of a broken seed, B re-
taining a part of the embryo. D, a sectional view of a seed. E, seeds, nat-
ural size.

(After Hillman, Bull. Nev. Agr. Exp. Sta.)

PORTULACACEAEH, PURSLANE FAMILY.
Purslane (Portulaca oleracea L.).

Seeds broadly ovate, inclined to kidney-shaped, flattened, one-
thirtieth in. in length, roughened by minute tubercles in concentric
rows; small scar at smaller end, whitish.

Cc

Fic. 282. Purslane (Portulaca oleracea). <A, a side view of a seed, enlarged,
showing the whitish scar; B, a group, natural size; C, section of a seed,
taken parallel with the faces.

(After Hillman, Bull. Nev. Agr. Exp. Sta.)

RANUNCULACEAE, CROWFOOT FAMILY.
Meadow Rue (Thalictrum dasycarpum Fisch. and Lall.).

Fruit an achene, ovoid, one-fifth in. in length, with remnant of
curved style, prominently ribbed, with from 6-8 wings, short-
stalked, glabrous or pubescent; seed elongated, ovoid, one-tenth in.
long, brownish, smooth, with prominent veins near base of seed.
Occasionally found in clover seed.

THE GENERAL CHARACTERS OF SHEDS 439

c
Figure 283A Figure 283B

Fie. 283. A. Meadow Rue (Thalictrum dasycarpum).
B. Long-fruited Anemone (Anemone cylindrica).
(A, drawing by L. R. Collins, B, by Ada Hayden.)

Long-fruited Anemone (Anemone cylindrica Gray).

Achenes one-quarter in. in length and one-fifth in. in width, flat,
compressed, 1-seeded, nearly orbicular, greenish, covered by dense
pilose mass of whitish hairs.

Prairie Larkspur (Delphinwm Penardi Huth.).

Seeds somewhat flattened, upper end wider, nearly square, 4-
angled or triangular, one-sixteenth to one-twelfth in. long, surface
scabrous, becoming rougher on angles; color grayish.

Figure 284A — Figure 284B Figure 284C

Fig. 284. <A. Prairie Larkspur (Delphiniwm Penardi).

B. and C. Field Larkspur (Delphiniwm consolida).

(A, drawing by Ada Hayden; B, drawn by L. R. Collins; C, drawn by C. M.
King.)

Field Larkspur (Delphiniwm consolida L.).

Seed angular, somewhat convex on back, one-twelfth in. long
and equally wide, surface scabrous or scaly, with whitish margins;
color blackish, brownish or grayish; seed with sharp bitter taste.
Reported as of frequent occurrence in Russian clover seed.

440. WEED FLORA OF IOWA

Small-flowered Crowfoot (Ranunculus abortivus L.).
Achene flattened-cireular, with 2 convex faces, orange-brown in
color, smooth and shining, very slightly impressed with wrinkles;

remnant of style present as a short curved point on margin.

Figure 285A Figure 285B
Fic. 285. <A. Small-flowered Crowfoot (Ranunculus abortivus). -a, achenes
enlarged; b, end view; c, achenes natural size.
B. Tall Buttercup (Ranunculus acris). a, b. different views of seed; ce, cross

section; d, natural size.
(After Hillman, Bull. Mich. Agr. Exp. Sta.)

Tall Buttercup (Ranunculus acris).

Carpel 1-ovuled; achene flattened, tipped by remnant of curved
style, one-tenth to one-eighth in. long; color greenish to brownish ;
surface apparently smooth, minutely pitted; scar minute, in a
whitish depression at base of achene.

PAPAVERACEAH, POPPY FAMILY.

Poppy (Papaver somniferum L.).

Seed about 1 mm. in length, kidney-shaped, one end being slightly
larger than the other; hilum and chalaza in a notch, connected by
a short raphe; surface covered with fine, beautiful reticulations;
embryo straight; considerable endosperm.

Figure 286A Figure 286B

Fic. 286. A. Poppy (Papaver somniferum). To the left embryo of seed.
B. Prickly Poppy (Argemone intermedia).
(A, after Winton. B, drawing, C. M. King.)

THE GENERAL CHARACTERS OF SEEDS 441
Prickly Poppy (Argemone intermedia Sweet).

Pod ellipsoid, prickly; seeds spherical, crested, about 2 mm. in
diameter; dark brown, surface reticulate and deeply pitted.

CRUCIFERAH, MUSTARD FAMILY.
Pennyeress (Thlaspi arvense L.).

Seed oblong, flattened, one-twelfth to one-tenth in. long; sur-
face marked by curved ridges, simple or occasionally forked, which
curve from base to apex in regular rows; color brownish to dark
reddish brown; funicle sharp poimted. Found largely in wheat,
barley and oats. “‘A pest of grain (wheat) fields of Manitoba.’’

Figure 287A Figure 287B

Fic. 287. A. Pennycress (Thlaspi arvense). A, side view of a seed; B, seeds,
natural size; C, the embryo.
B. Cress (Lepidiwm. sativum).
(After Hillman, Bull. Mich. Agr. Exp. Sta.)

Cress (Lepidium sativum L.).

Seed oval, one edge nearly straight, the other convex, one-tenth
in. in length, apparently slightly marginate at basal end, basal
portion bearing scar, also with white projecting tip, and end of
funicle prominent, smooth, brownish.

Small Peppergrass (Lepidium apetalum Willd.).

Seeds oblong, flattened, margin colorless, prominent ridge on
one side, one-sixteenth to one-twelfth in. long, minutely rough-
ened; cotyledons incumbent; seed coat becomes mucilaginous when
wet; funicle prominent. Generally found in small grains and
commercial grass seed.

442 WEED FLORA OF IOWA

Figure 288A ; Figure 288B

Fic. 288. A. Small Peppergrass (Lepidium apetaium). A, seeds shown in side
view; B, a half-section of a pod; C, a seéd in cross section, showing the
three parts of the embryo, the caulicle being at the right; D, the embryo,
the caulicle at the left; HE, group of seeds, natural size.

B. Lepidium apetalum, with section of seed coat showing action of mucilagin-
ous cells after moistening.

(A, after Hillman, Bull. Nev. Agr. Exp. Sta.; B, drawn by C. M. King.)

Large Peppergrass (Lepidium virginicum Lie

Seed elongated with prominent ridge on one side, one-twelfth in.
in length; color light reddish brown; cotyledons incumbent; seed

Fic. 289. Large Peppergrass (Lepidiuwm virginicwm). A, three seeds shown
in side view. The upper two show the narrow, curved groove of one face,
the lower one shows the broader, shallow depression of the opposite face.
The one immediately at the right of A shows the widened border and its
light colored edge. 3B, entire pod. C, a seed showing the mucilage as it
appears while wet. D is a cross sectional view of a seed, showing the
flattened form of the cotyledons and the edgewise position of the caulicle.
HE, the embryo in side view. F, seeds, pod, and half-pod, natural size.

(After Hillman, Bull. Nev. Agr. Exp. Sta.)

coat becomes mucilaginous when wet. Generally found in small
grains and commercial grass seed. Frequent in timothy.

THE GENERAL CHARACTERS OF SHEDS 443
Shepherd’s Purse (Capsella bursa-pastoris (.) Medic.).

Seed small, flattened, oblong, with 2 longitudinal grooves; one-
twenty-fourth to one-twentieth in. in length; color light brown; scar
whitish, funicle prominent. In alsike clover.

Fic. 290. Shepherd’s Purse (Capsella bursa-pastoris). A, seeds showing var-
ious forms and degrees of color. B, showing the mucilage while wet. CG,
a seed showing the appearance of the dried mucilage. D, a seed in cross
section. HH, seeds, natural size. ;

(After Hillman, Bull. Nev. Agr. Exp. Sta.)

False Flax (Camelina satwa (L.) Crantz).

Seeds one-twelfth in. in length, light brown, minutely pitted;
eaulicle prominent, running lengthwise with conspicuous groove

Fic. 291. False Flax (Camelina sativa). A, various forms of seeds. B, a seed
showing the mucilage. C, a seed in cross-section. D, seeds, natural size.
(After Hillman, Bull. Mich. Agr. Exp. Sta.)

between it and the cotyledons which are incumbent. On addition
of water the seeds become mucilaginous. In seeds of clovers and
orasses.

444 WEED FLORA OF IOWA

“Radish (Raphanus sativus L.).

Seed spherical, ovate to oval, frequently angular, one-eighth to
one-fifth in. in length, minutely pitted, brownish with glaucous or
shining surface; scar inconspicuous, usually surrounded by small
dark area; radicle near scar, prominent.

Fie. 292. Radish (Raphanus sativus), two different views.
(Drawn by C. M. King.)

White Mustard (Brassica alba Boiss.).

Seed nearly spherical, occasionally somewhat oblong, one-twelfth
to one-ninth in. long, light colored, reticulations inconspicuous;
scar whitish, projecting; seed coats mucilaginous when wet.

Figure 293A Figure 293A Figure 293B

Fic. 293. A. White Mustard (Brassica alba). B. Charlock (Brassica arven-
sis). a, tip of pod; b, seeds enlarged, and natural size; c, cross section.
(A, drawings by Ada Hayden and Ii. R. Collins; B, after Hillman, Bull. Mich.
gr. Exp. Sta.)

English Charlock (Brassica arvensis (l.) Ktze.).

Seed nearly spherical, sometimes oblong, one-fourteenth to one-
twelfth in. in diameter, marked with fine ridges, reticulated or
honeycombed in appearance, light brown or grayish, with paler
appearance; scar whitish, an elevated point at one end of the
seed ; embryo large; cotyledons conduplicate. Only a small amount
of mucilage produced in presence of water.

THE GENERAL CHARACTERS OF SEEDS 445

Wild Turnip (Brassica campestris L.).

Seeds generally nearly spherical or oblong; the caulicle and
radicle usually conspicuous along the middle, one-twentieth to one-
twelfth in. in diameter, cultivated forms larger, roughened and

Fig. 294. Wild Turnip (Brassica campesiris). A and B, various forms of
seeds. C, a seed in cross section showing cotyledons and caulicle. D, the

embryo. E, seeds, natural size.
(After Hillman, Bull. Mich. Agr. Exp. Sta.)

more finely ridged than in B. nigra and B. arvensis; color grayish
or brownish; scar at one end. With clover and grass seed.

Rape (Brassica napus L.).

Seed nearly spherical or sometimes oblong, one-fourteenth to one-
twelfth in. in length, prominently reticulated; closely resembles
B. arvensis. Found in mustard and clover seed.

< 2
@ 9 a)
(oe) eo : 5)
oe 0 ig
B. ” A ae
Figure 295A Figure 295B

Fic. 295. A. Rape (Brassica napus). B. Black Mustard (Brassica nigra). A,
seed enlarged, showing the surface network of dark lines. B, a group of

seeds, natural size.
(A, drawings by Ada Hayden; B, after Hillman, Bull. Mich. Agr. Exp. Sta.)

Black Mustard (Brassica nigra (l.) Koch.).

Seed nearly spherical, more generally broadly oblong, one-twen-
tieth to one-fifteenth in. in diameter; surface marked with fine
ridges; frequently whitish scar at one end; embryo as in B.

446 WEED FLORA OF IOWA

arvensis; taste pungent. Generally found in seed of clover and
alfalfa.

Indian Mustard (Brassica juncea).

Seed about the size of wild mustard seed; surface rather coarsely
reticulated. Color dark reddish brown.

Figure 296A Figure 296B

Fic. 296. A. Indian Mustard (Brassica juncea). B. MWHare’s-ear Mustard
(Conringia orientalis). a, b, different views of seed; ec, cross section; d,
natural size.

(After Hillman, Bull. Mich. Agr. Exp. Sta.)

Hare’s-ear Mustard (Conringia orientalis (i.) Dumort.).

Pod rigid, 4-angled; seeds brown, oblong narrowed to rounding
at the ends, 2-2.5 mm. long; surface finely reticulated in checks;
sear at end of seed lighter in color; position of caulicle indicated
by two distinct, lengthwise grooves.

Tumbling Mustard (Sisymbriwm altissimum L.).

Seed oblong flattened, one-twenty-fifth in. in length; color reddish
yellow; radicle prominent, variable in shape; form of embryo
marked by deeper color, by lines; seed coat becomes mucilaginous
when wet. A tumbling weed. Distribution wide, reported as a
sericus weed in commercial seeds of the northwest and Canada.

Hedge Mustard (Stsymbrium officinale (i.) Seop.).

Seed oblong, sometimes with upper end truncate, some almost
trapezoidal in outline, one-twenty-fourth to one-sixteenth in. long;
color yellowish, or brownish, variable; caulicle evident from promi-
nent white scar; funicle sometimes present and pointed; seed coat
mucilaginous. Found in alsike and white clovers.

THE GENERAL CHARACTERS OF SEEDS 447

Figure 297A Figure 297B

Tig. 297. A. Tumbling Mustard (Sisymbrium altissinum). A, a group of
seeds indicating the usual forms; a, one showing the hairy appearance due
to the mucilage, either when wet or after drying. B, several seeds, natural
size.

BR. Hedge Mustard (Sisymbriuwm officinale). A, a group of seeds showing the
prevailing forms; a, one showing the fine hairlike mucilage as it appears
when wet or after drying. B, group showing the natural size.

(After Hillman, Bull. Mich. Agr. Exp. Sta.)

Marsh Cress (Radicula palustris (.) Moench.).

Pod ovoid; seed pale reddish brown, oval, finely reticulated,
length about .6 2-3 mm.; scar near one end, occupying a deep
notch in the contour of the margin.

Fic. 298. Marsh Cress (Radicula palustris).
(Drawing by Ada Hayden.)

Winter Cress (Barbarea vulgaris R. Br.).

Seed oblong, flattened, one-sixteenth in. in length; surface finely
reticulated ; the scar a light-colored appendage at one end; position

Fic. 299. Winter Cress (Barbarea vulgaris). A, various forms of seeds. B, a
seed in cross section. C, seeds, natural size.
(After Hillman, Bull. Mich. Agr. Exp. Sta.)

448 WEED FLORA OF IOWA

of caulicle marked by groove; color light brown; seed coats do not
develop mucilage in water. ‘Oueseionall’y with cover

CAPPARIDACEAE, CAPER FAMILY.
Rocky Mountain Bee-plant (Cleome serrulata Pursh.).

Roughly wedge-shaped to triangular in outline, and wedge-
shaped in eross section; mature seeds of a grayish brown eolor,
immature seeds a creamy yellow; size 3 by 2.5 mm.; basal scar ex-

Fic. 300. Rocky Mountain Bee-plant (Cleome serrulata).
(Drawing by Ada Hayden.)

tends from the edge of the wedge, well up on both flat faces;
most of the surface of the seed roughly tubercled.

ROSACHAH, ROSE FAMILY.
Silver Weed (Potentilla anserina L.).

Seed pointed, egg-shaped, unsymmetrical, about 1.6 mm. in
length; color yellowish to brown; surface furrowed throughout its
length.

Fic. 301. Silver Weed (Potentilla anserina).
(After Burchard.)

Cinquefoil (Potentilla canadensis L.).

Seed small, about 0.5 mm. in length, short, obliquely egg-shaped ;
light brown.

THE GENERAL CHARACTERS OF SEEDS 449

Figure 302A Figure 302B

Fig. 302. A. Cinquefoil (Potentilla canadensis). B, Five-finger (Potentilla mon-
speliensis var. norvegica). A, two seeds (achenes), side view. B, a seed
in edge view. C, group showing the natural size.

(After Hillman; A, Bull. Mich. Agr. Exp. Sta.: B, Bull. Nev. Agr. Exp. Sta.)

Five Finger (Potentilla monspeliensis L. var. norvegica (L.)
Rydb.).

* Achenes small, ovate or kidney-shaped, one-twenty-fourth in. in
length, prominently ridged; the ridges simple or branched, starting
from base of seed; color light brown or straw-colored. Frequently
occurs in alsike clover and timothy, as well as in red clover.

Avens (Geum canadense Jacq.).

Achene pale greenish brown, length 3 mm., width 1144 mm., gen-
eral shape ovate, tapering to base, rounded at apex which bears
persistent hooked style 5 mm. in length tipped with a hook; achene
slightly flattened, with a narrow ring along each edge.

Figure 303A Figure 303B

Fic. 303. <A, Avens (Geum canadense). B, Rose (Rosa pratincola).
(Drawings by C. M. King.)
29

450 WEED FLORA OF IOWA

Prairie Rose (Rosa pratincola Greene).

Achenes dark to light brown, smooth, shining; length 3-5°mm.,
width 2-3 mm., general shape ovoid, modified by some flattening of
portions at the surface, and corresponding angulation of the seed’s
form; scar at broader end, with dark line extending to the apex
which is tipped with a slight remnant of the style.

LEGUMINOSAE, PULSE FAMILY.
Rattlebox (Crotalaria sagittalis L.).

Pod blackish, cylindrical, inflated, many seeded; seed greenish
brown, shining, smooth, somewhat flattened, circular-kidney-shaped,

Fic. 304. Rattlebcox (Crotalaria sagittalis).
(Drawing by Ada Hayden.)

with one side interrupted by a deep rounded notch, bearing the
conspicuous scar with dark center and light rim; width of seed
2.5 mm. ik

White Clover (Z'rifoliwm repens L.).

Seeds varying from nearly square to triangular, margins rounded,
flattened, often concave on one margin, one-twentieth to one-thir-
tieth in. long; smooth; color dull yellow to light reddish brown, or
slightly green; radicle slender club-shaped, about as long as the
cotyledons.

Alsike Clover (Trifolium hybridum L.).

Seed more nearly round than that of alfalfa or red clover; one-
twentieth to one-sixteenth in. in length; color a peculiar yellowish
green, often brown and mottled, individual seeds even yellow or
brown; the projecting radicle gives the seed the appearance of hay-
ing a nearly square top.

THE GENERAL CHARACTERS OF SEEDS 451

Figure 305A Figure 305B

Figure 305C Figure 305D

Fic. 305. A. White Clover (Trifolium repens). a, enlarged; b, natural size.
B. Alsike Clover (Trifolium hybridum). a, enlarged; b, natural size.
C. Red Clover (Trifolium pratense). a, enlarged; b, natural size.
D. Low Hop Clover (Trifolium procumbens). a, enlarged; b, opposite face; e,
flower; d, seeds, natural size.
(After Hillman, Bull. Nev. Agr. Exp. Sta.)

Red Clover (Trifoluum pratense L.).

Seeds roughy triangular, with angles rounded; no two sides equal
length, sides somewhat convex with rounded edges, one-sixteenth
to one-tenth in. long; color light yellow, purple, or of yellow and
purple; old seeds more brownish; scar near radicle, which is not
SO prominent as in other clovers; the seeds of mammoth clover re-
semble those of red clover but are usually larger.

Low Hop Clover (Trifolium procumbens U.).

Seed light brown, shining, oval, length 1-1.3 mm., width 0.6 mm.;
sear in a notch a short distance from one end.

Sweet Clover, Bokhara Clover (Melilotus alba Desv.).

Seeds contained in an ovoid pod, one-twelfth to one-fifteenth in.
long, reticulated, nearly smooth, elliptical, somewhat triangular,
variable; color yellowish to greenish, sear brown in color; micropi-
lar processes near scar, not conspicuous. Found in seeds of alfalfa
and clover.

452 WEED FLORA OF IOWA

Fic. 306. White Sweet Clover (Melilotus alba). A, a group of seeds. B, the
pods; the central one without the calyx. C, the embryo. D, a group of
seeds and pods, natural size.

(After Hillman, Bull. Nev. Agr. Exp. Sta.)

Yellow Sweet Clover (Melilotus officinalis (L.) Lam.).

Pods one-seventh in. in length; rugose, more evenly transversely
wrinkled than in M. alba; seeds subspherical or elliptical to kidney-

Fic. 307. Yellow Sweet Clover (Melilotus officinalis). A, seeds. B, pods; the
one at the right without the calyx, and showing the contracted base. C, a
view of a seed in cross section, showing cotyledons and caulicle. D, a group
of seeds and pods, natural size. F ;

(After Hillman, Bull. Nev. Agr. Exp. Sta.)

shaped, one-twelfth to one-tenth in. in length, smooth; yellowish or
brownish to greenish; with small micropilar processes.

Bur Clover (Medicago hispida Gaertn.).

Seeds kidney-shaped, occasionally sausage-shaped, both sides con-
vex, one-sixth in. in length, larger than alfalfa, variable in size;
color lighter than in alfalfa seed; scar about middle of seed, close
to prominent micropilar processes; pods large, spirally twisted into
several flat coils, covered by pointed projections; the prickles either
straight or curved; each pod several-seeded; seeds have general re-
semblance to alfalfa seed in form and color.

THE GENERAL CHARACTERS OF SHEDS 453

A A B
Fic. 308. Bur Clover (Medicago hispida). A, seed; B, pod.
(Drawings by Ada Hayden and L. R. Collins.)

Yellow Trefoil (Medicago lupulina L.).

Seeds kidney to egg-shaped, much shorter than bur clover seed,
one-twelfth to one-tenth in. long; about the size of alfalfa, which
it closely resembles ; color yellowish, reddish, or greenish; scar near

Fic. 309. Yellow Trefoil (Medicago lupulina). A, seeds showing the prevail-
ing forms. B, pods; the central one with the calyx removed; the one at
the left an immature, lighter colored specimen. C, a view of a seed in cross
section, showing cotyledons and caulicle. D, the embryo. EH, seeds and
pods, natural size.

(After Hillman, Bull. Nev. Agr. Exp. Sta.)

one end; micropilar processes prominent; the pods clustered at.the
end of the peduncle small, black, wrinkled, and coiled at tip, marked
by prominent veins and hairs; each pod contains one seed.

Dalea (Dalea alopecuroides Willd.).

Seeds triangular to kidney-shaped, one-tenth in. in length; mi-
eropilar scar prominent, with whitish border and 2 micropilar
processes; surface shining, slate-colored. Found in clover seed,
from ‘which it is separated with difficulty.

454 WEED FLORA OF IOWA

Figure 810A Figure 310B Figure 310C

Fig. 310. A, Dalea (Dalea alopecuroides). B, seed of Pink Dalea (Dalea
laxiflora). C, seed-pod of the same species.
(A, drawing by L. R. Collins; B and C, by C. M. King.)

Pink Dalea (Dalea laxiflora Pursh.).

Seeds one-tenth in. in length, generally triangular, somewhat
kidney-shaped, one end projecting beyond sac, which is circular
and has two micropilar processes on one side; yellowish or brownish
in color; leaves have pellucid dots. This should enable one to recog-
nize the impurity. Occasionally found in clover seed.

Stemless Loco Weed (Ozxytropis lamberts Pursh.).

Pods coriaceous, silky pubescent, cylindrical; seed flattened,
brown, about 2 mm. broad and 2.5 mm. long.

Figure 311A Figure 311B Figure 311C

Fic. 311. A, Stemless Loco Weed (Ozytropis lamberti). B, Bush Clover
(Lespedeza capitata), pod and seed.
(Drawings A, by Ada Hayden; B, by Charlotte M. King.)

Bush Clover (Lespedeza capitata Michx.).

Pod ovate-oblong, one-sixth in. in length, sessile, 1-ovuled, pu-
bescent, brownish, reticulated, indehiscent, seed scarcely kidney-
shaped, one-tenth in. in length, greenish to purplish.

THE GENERAL CHARACTERS OF SHEDS 455

Common Vetch (Vicia satwa L.).

Pod linear, several-seeded ; seeds nearly spherical or compressed
on the sides, variable, blackish to brownish.

Fig. 312. Common Vetch (Vicia sativa).
(After Hillman, Circular U. S. Dept. Agr.)

Hairy Vetch (Vicia villosa Roth.).

Seeds spherical to subspherical ; one-tenth to one-sixth in. in diam-
eter; blackish or brownish, surface smooth; scar elongated, repre-

Fic. 313. Hairy Vetch (Vicia villosa).
(Hillman, U. S. Dept. of Agriculture.)

sented by a narrow line slightly elevated, with depressed center,
light in color, brownish to straw-colored.

Trailing Wild Bean (Strophostyles helvola (.) Britton).

Pod terete, 5-7.5 em. long, nearly glabrous, 4-8-seeded, dark
brown; seed cylindrical, rounded, truncate at both ends; length
6 mm., width 4.5 mm.; color dull brown slightly mottled; narrow
white scar along inner angle, nearly the entire length of the seed;
seed strongly angled longitudinally on side opposite scar.

Fie. 314. Wild Bean (Strophostyles helvola).
(Drawing by L. R. Collins.)

456 WEED FLORA OF IOWA

LINACEAE, FLAX FAMILY.
Common Flax (Linum usitatissimum L.).

Seeds ovate, flattened, one-fifth in. long, one-tenth in. wide, basal
end curved on one side; color brown, margins with whitish luster,

Figure 315A Figure 315B

Fic. 315. Common Flax (Linum usitatissimum). A, seed. B, cross section
of seed.
(A, drawing by Ada Hayden; B, after Winton.)

smooth, shining; scar on one side, near lower end, small, incon-
spicuous; embryo, large, straight.

OXALIDACEHAH, SORREL FAMILY.
Lady’s Sorrel (Oxalis corniculata L.).

Pod prismatic, cylindrical, seeds 1 mm. in length; shape and
markings similar to preceding.

Oxalis (Oxalis stricta L.).

Pod angled, awl-shaped; seeds 1 mm. in length, elliptical, pointed
at one end; surface marked by broken transverse lines of white;
seed longitudinally ribbed, slightly flattened.

THE GENERAL CHARACTERS OF SEEDS 457

Figure 316A Figure 316B Figure 316B

Fic. 316. A, Storksbill or Alfilaria (Hrodium cicutarium) ; A, a seed-vessel
with a portion of its spirally coiled awn. 3B, a seed-vessel and its awn,
natural size. (In many the awn is smaller.) C, a seed, magnified. D, a
line showing the length of the seed. HE, the embryo removed from the seed
coats, the parts spread.

B. lLady’s Sorrel or Yellow Field Sorrel (Oxalis corniculata).
(A, after Hillman, Bull. Mich. Agr. Exp. Sta.; B, drawings by C. M. King.)

GHRANIACEAH, GHRANIUM FAMILY.
Storksbill (Hrodiwm cicutarium Li’Her.). |

Lobes of capsule 1-seeded, with elastic, dehiscent style, coiled at
maturity, villous inside; hairs at base pointing obliquely upwardly ;
awn coiled for half its length; seed broadly club-shaped, one-fifth
in. in length without awn; scar removed one-third length of seed
from base; groove from scar to tip of seed.

HUPHORBIACHAH, SPURGH FAMILY.
Three-seeded Mercury (Acalypha virginica L.).

Seeds ovoid; one-twelfth to one-twentieth in. long; reddish, min-
utely striate, line running from apex to base; scar at smaller end.
Found in clover seed.

Figure 317A Figure 317B

Fic. 317. A. Three-seeded Mercury (Acalypha virginica). a and b, different
views of seed; c, sectional view showing embryo and endosperm; d, seed,
natural size.

B. Prostrate Spurge or Milk Spurge (Huphorbia maculata). A. Different

views of seed. B. Seeds, natural size.
(After Hillman, Bull. Mich. Agr. Exp. Sta.)

458 WEED FLORA OF IOWA

Upright Spurge (ELuphorbia presli Guss.).

Seeds lead-colored, obovoid-oblong, with 4 unequal sides; surface
pitted and transversely wrinkled; a narrow dark raphe along one
edge; length 1-1.3 mm.

Fic. 318. Seeds of Spotted Spurge (Huphorbia preslii). A and B, different
views of seed. D. Fruit. E. Seed, natural size.
(After Hillman, Bull. Mich. Agr. Exp. Sta.)

Flowering Spurge (Euphorbia corollata L.).

Seeds ovoid, one-tenth in. in length, smooth, brownish, a line
extending from apex to base on one side, with whitish bordered
depression at base; apical point on larger end; seed coat mucilagin-
ous.

Figure 319A | ' Figure 319B

Fic. 319. <A. Flowering Spurge (Euphorbia corollata.) ;
B.. Snow-on-the-Mountain (Euphorbia marginata). : ‘
(Drawing by Ada Hayden.)

Milk Purslane (Euphorbia maculata L.).

Seeds ovoid or oblong, obtusely angled, one-twentieth in. in
length, minutely pitted and transversely wrinkled; grayish.

Snow-on-the-mountain (Huphorbia marginata Pursh.).

Seed ovoid, slightly flattened at apical end, length 4 mm., width
3 mm.; color light brown; surface roughly tuberculate; one side
marked by a dark longitudinal line.

Png ihe

THE GENERAL CHARACTERS OF SEEDS 459

MALVACEAE, MALLOW FAMILY.

Velvet-leaf, Butterprint (Abutilon theophrasti Medic.).

Carpels 2-valved, beaked, each usually 2-seeded; seeds somewhat
triangular, kidney-shaped, one-eighth in. in length, minutely granu-
lar and pubescent; color blackish gray; funicle extending to notch
of seed. May occur in small grain.

Ca ¢
@
@

Figure 320A Figure 320B

Fig. 320. A. Indian Mallow or Butterprint (Abutilon theophrasti). a, b, c,
different views of seed; d, cross section showing embryo and caulicle;. e,
seeds, natural size.

B. Seeds of Bladder Ketmia. a and b, different views, c, natural size.
(After Hillman, Bull. Mich. Agr. Exp. Sta.)

Prickly Sida (Sida spinosa L.).

Seeds oval, one-sixteenth to one-twelfth in. long, one face con-
vex, the other with a prominent ridge across its length; scar at
broad end; surface dull, smooth; color brownish. Reported in seed
of Missouri red clover.

c S g

Fie. 321. Prickly Sida (Sida spinosa). A, different views of seeds. B, a seed
in section taken midway between the two extremities, showing embryo and
caulicle. C, seeds, natural size.

(After Hillman, Bull. Nev. Agr. Exp. Sta.)

460 WEED FLORA OF IOWA

Common Mallow (Malva rotundifolia L.).

Commonly called cheeses. Carpels arranged about a center, flat,
beakless, indehiscent ; each carpel a single seed, kidney-shaped, one-
sixteenth to one-twelfth in. in diameter, flattened, with a prominent

Fic. 322. Common Mallow (Malva rotundifolia). A, two seeds in side view.
B, a seed retained by a carpel of the seed-vessel. C, a seed in cross section
taken midway between the scar and the opposite edge. D, seeds, showing

the natural size.
(After Hillman, Bull. Mich. Agr. Exp. Sta.)

notch at base; seeds brownish or gray, minutely granular; scar
small, frequently containing spongy tissue; embryo curved; small
amount of endosperm. Reported in alfalfa and red clover seed.

Bladder Ketmia (Htbiscus trionum L.).

Ciapsule 5-valved, globose-ovoid, hairy ; seeds kidney-shaped, one-
fifteenth in. in length, blackened, roughened by short tubercular
processes, minutely granular; basal end of seed of much smaller
diameter; scar brownish; funicle extending to the notch.

ONAGRACEAE, EVENING PRIMROSE FAMILY.
Evening Primrose (Oenothera biennis L.).

Seeds prismatic, 4 or 5-sided, sometimes curved, variable, one-
sixteenth in. in length, slightly wing-margined, rugose, brown, scar
indistinct at one end, embryo straight.

UMBELLIFHRAH, PARSLEY FAMILY.
Water Hemlock (Cicuta maculata L.).

Fruit ovate to oval, curved or nearly straight, one-eighth in. in
length, smooth, with longitudinal brown and straw-colored lines;
apex widened with 2 styles; ribs corky; oil-tubes solitary, in the
intervals.

THE GENERAL CHARACTERS OF SHEDS 461

B

Figure 323B

Fic. 323. A. Evening Primrose (Oenothera biennis). A, different views of
seed. B, cross section of seed. C, natural size.
B. Water Hemlock (Cicuta maculata).
(After Hillman, Bull. Mich. Agr. Exp. Sta.)

Wild Parsnip (Pastinaca satiwa L.).

‘“Seeds’’, carpels one-quarter in. in length, thin, circular or
oblong; color light or dull yellowish brown; lighter conspicuous
margin, ribs brownish or reddish ; apex notched, with a conspicuous
remnant of the style; oil tubes four, alternating with the ribs;
inner face concave, with a central longitudinal ridge and one oil-
tube on each side.

Wild Carrot (Daucus carota L.).

Fruit one-eighth in. long, oblong, flattened dorsally ; carpel with
5 slender, bristly, primary ribs bearing numerous spines, and 4
secondary wings; color whitish yellow; oil-tubes one under each
row of spines, and two between the ridges of the inner face; seeds
commonly found with spines broken off. In alfalfa and clover
seeds.

462 WEED FLORA OF IOWA

Figure 324A

Figure 324B

Fic. 324. A and Al. Wild Parsnip (Pastinaca sativa). B. Wild Carrot
(Daucus carota). <A, the outer (at left) and inner (at right) faces of a
seed (carpel). The spines occupy the margin and two rows along the
outer face. The slender, hairy ridges alternate with the rows of spines.
The inner face bears two, separated by a slender ridge or line which is not
hairy. B, an oblique view of the outer face of a seed found with clover
seed. C and D, views of the inner face of seeds similarly found. EH, seeds,
natural size. ‘

(A, after Hillman, Bull. Nev. Agr. Exp. Sta.; Al, drawing by L. R. Collins;

B, after Hillman.) ;

ASCLEPIADACEHAH, MILKWEED FAMILY.
Swamp Milkweed (Asclepias incarnata L.).

Seeds oval, wing-margined, three-tenths in. in length; surface less
prominently veined than in A. syriaca; raphe marked by distinct
ridge; coma attached to smaller end of fine silky hairs. Probably
never in commercial seed.

Common Milkweed (Asclepias syriaca).

Seeds flattened, oval or elliptical, apical end truncate, three-
tenths in. in length, wing-margined; seed and wing distinctly
veined ; the raphe occurs in form of a distinct ridge on inner face of
seed; coma a tuft of silky hairs attached to apical end, easily sepa-
rated from seed. Not apt to be found in commercial seed.

463

THE GENERAL CHARACTERS OF SEEDS

Figure 325C Figure 325D

Figure 325B

Figure 325A
B. Common Milkweed

Fic. 325. A. Swamp Milkweed (Asclepias incarnata).
a, b, different views of seed; c, cross section; d, ®,
D. Whorled

(Asclepias syriaca).
Butterfly Weed (Asclepias iuberosa).

natural size. Cr

Milkweed (Asclepias verticillata). ;
(A, drawing by L. R. Collins; B, after Hillman; C, D, by C. M. King.)

Butterfly Weed (Asclepias tuberosa Ite)

Seed ovate or eliptical, three-tenths in. in length; surface rough-
ened by ridges on both back and inner faces; winged margin,
lighter brown than middle part of seed; raphe marked by a distinct

ridge; coma, fine, silky, smooth.
Whorled Milkweed: (Asclepias verticillata L.).
Seeds ovate, one-sixth in. in length, margin distinct, lighter in

color than the rest of the reddish brown seed; surface veined, but
not ridged or roughened; raphe a distinct ridge on inner face;

coma soft, silky; very smooth.

CONVOLVULACEAE, CONVOLVULUS FAMILY.
Common Morning-glory (Ipomoea purpurea (L.) Roth.).

Seed dark brown, with one convex side opposite to 2 flattened
faces meeting at an angle, length 5 mm., width 4 mm. at the base
of the seed; at lower end of the angle between the two flattened
faces is the scar, also dark brown; surface dull, finely roughened.

Small Bindweed (Convolvulus arvensis L.).

Seeds large, oval, one side convex, the other side with a broad
ridge; one-sixth in. long, a depression at one extremity representing
the scar; surface of seed roughened, dark brown in color; embryo
large, surrounded by the fleshy endosperm. Found in cereal grains.

464 WEED FLORA OF IOWA

Figure 326A

Figure 3260

Fic. 326. A. Common Morning-glory (Ipomoea purpurea). B. Small Bind-
weed (Convolvulus arvensis). a, b, different faces of seed, c, cross section,
d, natural size. C. Wild Morning-glory (Convolvulus sepium). a, b, dif-
ferent faces of seed, c, natural size.
(A, drawing by Charlotte M. King; B and C, after Hillman.)

Wild Morning-glory (Convolvulus sepium L.).

The outer surface rounded; inner face with prominent ridge and
a depression on each side; seed one-quarter in. long; smooth, brown-
ish or blackish, with minute projections over the surface; hilum
prominent, light brown, in semicircular depression.

Field Dodder (Cuscuta arvensis Beyrich.).

Capsule globose, indehiscent; seed spherical to kidney-shaped, or
ovate, occasionally with prominent angles; one-twenty-fourth to
one-sixteenth in. long; roughened but not pitted, dull yellowish,
grayish or light brown; scar at one extremity, frequently elevated
and prominent; Mr. Hillman finds field dodder seeds usually lighter
than those of Chilean dodder; in some samples the Chilean dodder
seeds are the lighter in color. Appears in clover seed, in many cases
abundantly.

Fic. 327. Field Dodder (Cuscuta arvensis).
(A, after Hillman, Bull. Nev. Agr. Exp. Sta.; B, drawing by C. M. King.)

THE GENERAL CHARACTERS OF SEEDS 465

Clover Dodder (Cuscuta epithymum Murr.).

Seed spherical or subspherical, one-thirtieth to one-twenty-fourth
in. in diameter ; surface roughened, with appearance of sponginess,
dull, usually ashy, yellowish to light or dark brown, or purplish;
embryo coiled, without cotyledons, consisting of slender tapering

Fig. 328. Clover Dodder (Cuscuta epithymum). A, a group showing various
forms and views of seeds. B and C, seeds having the scurfy appearance.
D and # show the angled, scar-bearing face, EH, being one of the light-
colored, sterile seeds. F, a torn, dried flower having the seed-vessel intact.
G, the embryo. H, group of seeds showing the natural size.
(After Hillman, Bull. Ney. Agr. Exp. Sta.)

body, with caulicle and radicle embedded in fleshy endosperm.
Commonly distributed in seed of clovers and alfalfa. Brown ard
Hillman state that this dodder is almost entirely confined to Euro-
pean grown seed, since the plant does not generally produce seed
in this country.

Chilean Dodder (Cuscuta sp.)

Seeds spherical to subspherical or oval, inclined to be more angu-
lar than the preceding species, flattened on one side, one-seventeenth
to one-fifteenth in. in diameter, about the size of large field dodder
seeds; dull brownish, minutely roughened; scar prominent, at end
of flattened surface, hghter in color than rest of seed. Found in
both clover and alfalfa seed, from which it is screened with dif-
ficulty.

Fie. 329. Chilean Dodder (Cwscuta chilensis).
(Drawing after Burchard.)

30

466 _ WEED FLORA OF IOWA

BORAGINACEAE, BORAGE FAMILY.
Common Hound’s Tongue (Cynoglossum officinale L.).

Ovary dividing into 4 achenes, each 5-7 mm. in length, ovate to
round, flattened; lower side bearing large ovate scar; surface coy-
ered with straight, stiff, barbed prickles.

Fic. 330. Common Hound’s Tongue (Cynoglossum officinale). a, b, views of
different faces of seed; c, natural size.
(After Hillman, Bull. Mich. Agr. Exp. Sta.)

Wild Comfrey (Cynoglossum boreale Fernald.).

Nutlets convex on the upper face, somewhat triangular, one-
seventh in. in diameter, bearing short barbed prickles on convex
surface; color brown.

Fic. 331. Wild Comfrey (Cynoglossum boreale).
(Drawing by Ada Hayden.)

Stickseed (Lappula echinata Gilibert).

Ovary separating into 4 achenes, 2.5 mm. long, slightly flattened
from ovate, under surface tuberculate, bearing straight ridge from
point to middle; on the upper side, the margins bear a double row
of slender barbed prickles.

Beggar’s Lice (Lappula virginiana (L.) Greene).

Achenes 3 mm. long, borne in clusters of 4, broadly ovate, flat-
tened on outer side; the outer surface bearing short stiff barbed
prickles, the inner sake cone shaped, free feed hairs, and bearing
a triangular scar.

THE GENERAL CHARACTERS OF SEEDS 467

Figure 332A Figure 332B

Fic. 332. A. Stickseed (Lappula echinata). a, b, views of different faces of
seed; c, natural size.
B. Beggar’s Lice (Lappula virginiana). a, b, views of different faces of seed; c,
natural size.
(After Hillman, Bull. Mich. Agr. Exp. Sta.)

Narrow-leaved Puccoon (Ltthospermum angustifolawm Michx.).

Nutlets ovoid, keeled on inner face, one-eighth in. long; surface
smooth, shining, pitted; color white to yellowish white; base irreg-
ular with projecting margin; bearing base with projecting ridges.

Fig. 333A Fig. 333B

Fic. 333. A. Narrow-leaved Puccoon (Lithospermum angustifolium).
B. American Gromwell (Lithospermum latifolium).
(Drawings by L. R. Collins).

American Gromwell (Lithospermum latifolium Michx.).

Nutlets ovoid to globose, one-sixth in. in diameter, white, shining;
glabrous but prominently pitted ; base oblique.

Corn Gromwell (Lithospermum arvense L.).

Ovoid nutlets 4 or fewer, convex on back, inner face with distinct
ridge ; one-sixteenth to one-twelfth in. in length; color from whitish
to dark brown, surface glabrous, but wrinkled and pitted; base
obliquely flattened, bearing the scar. Reported to occur with
grain seed.

468 WEED FLORA OF IOWA

Figure 334A Figure 334B

Fic. 334. A, Corn Gromwell (Lithospermum arvense). A, different views of
nutlets, B, one bearing the flower-receptacle and portion of the stem, C,
the natural size of the larger nutlets.

B, Viper’s Bugloss (Echiwm vulgare).
(A, after Hillman, Bull. Mich. Agr. Exp. Sta.; B, drawn by L. R. Collins.)

‘

Viper’s Bugloss (Echiuwm vulgare L.).

Nutlets erect, ovoid, one-eleventh in. in length, back distinctly
convex; seed straight or curved; outer face with distinct mdge;
surface rugose; color white, base flattened.

VERBENACEAHEH, VERVAIN FAMILY.
Large-bracted Vervain (Verbena bracteosa Mx.).

Nutlets cylindrical, 3-sided, outer face convex, one-tenth in. in
length, outer face rugose at upper end, lower end marked by lines,
inner face pitted, sear somewhat elevated, whitish. In seeds of
clovers and grasses.

Figure 335A Figure 335B

Fic. 335. A. lLarge-bracted Vervain (Verbena bracteosa). B. Blue Vervain
(Verbena hastata). A, the outer face, and B, the inner face of a nutlet; the
latter shows the whitish, spongy scar at the base. C, a group showing the
natural size. D, a section of a nutlet, taken lengthwise.

(A, drawing by C. M. King; B, after Hillman, Bull. Nev. Agr. Exp. Sta.)

THE GENERAL CHARACTERS OF SHEDS 469

Blue Vervain (Verbena hastata L.).

Nutlets 3-sided, with a distinct line of separation, back convex,
rugose, inner face 2-sided; one-fifteenth to one-thirteenth in. long;
color light brown; scar slightly elevated, whitish, at base of nut-
let. Often found in seed of clover.

Hoary Vervain (Verbena stricta Vent.).

Nutlets cylindrical, 3-sided, one-eighth in. in length, outer face
convex, back with 4 prominent veins, upper portion slightly pitted ;
eolor dark brown; whitish scar at base. Seed found in clover.

Figure 336A Figure 336B

Fic. 336. A. Hoary Vervain (Verbena stricta). B. White Vervain (Verbena
urticaefolia) .
(A, drawing by lL. R. Collins; B, after Hillman, Bull. Mich. Agr. Exp. Sta.)

White Vervain (Verbena urticaefolia L.).

Nutlets cylindrical, convex on back, 2-faced on inner side, with
prominent central line; one-tenth to one-eighth in. in length; back
somewhat rugose, with 2 or 3 prominent lines extending from base
to apex and some cross lines; inner face somewhat granular; scar
a whitish elevated point. Found in seeds of clovers.

LABIATAE, MINT FAMILY.

Catnip (Nepeta cataria L.).

Oval, dark brown seeds, about 1.5 mm. in length, slightly flat-
tened, surface smooth; one face bears a broad central, longitudinal
ridge, the base of which is marked by two white characteristic
spots, which are a part of the scar.

American Germander (Teucriuwm canadense L.).

Nutlets obovoid, one-tenth in. in length, outer surface convex;
color brown ; surface prominently rugose, reticulated except the scar
at the lower end. Common in commercial seed.

470 WEED FLORA OF IOWA

Figure 337A Figure 337B

Fic. 337. <A. Catnip (Nepeta cataria). A, views of various seeds (nutlets),
three showing the scar-marking. B, one having the nutlet wall partially
broken away, exposing the seed proper. OC, a nutlet in longitudinal section,
showing the embryo. D, group showing the natural size.

B. American Germander (Teucrium canadense).
(A, after Hillman, Bull. Nev. Agr. Exp. Sta.; B, drawn by L. R. Collins.)

Horehound (Marrubium vulgare L.).

Seed ovate, one side convex, flattened side divided into 2 faces
by strong central ridge; one-twelfth of an inch in length; brownish

Figure 338A

Figure 338B

Fic. 338. A. Giant Hyssop (Agastache scrophulariaefolia).
B. Common Horehound (Marrubium vulgare); a, angled face; b, convex face;
ce, longitudinal section; d, transverse section; e, natural size of seed.
(A, drawing by L. R. Collins; B, after Hillman, Mich. Agr. Exp. Sta.)

or blackish, with straw-colored markings; scar inconspicuous, in a
slight depression somewhat paler in color than seed.

Self-heal (Prunella vulgaris L.).

Nutlets ovoid, faces convex, marked by longitudinal grooves;
one-twelfth of an inch in length; smooth, shining; color brown;
small bud marked by white scar appendage. Found in red clover.

Motherwort (Leonurus cardiaca L.).

Nutlets 3-sided, occasionally flattened, 1.10 in. long, smooth ex-
cept upper end, which is papillose; minutely roughened; straw-
colored to brownish. Found in cultivated grass seed.

THE GENERAL CHARACTERS OF SHEDS 471

Figure 339A Figure 339B

Bis. 339. <A. Self-heal (Prunella vulgaris). A, a group of seeds, enlarged, the
lower left-hand one with the scar-appendage broken away; the upper left-
hand one showing the outer face. B, a group showing the natural size; C,
a longitudinal section of a seed, showing the embryo.

& Motherwort (Leonurus cardiaca). a and b, different views of seed, c, seed,

; natural size. , 4

(After Hillman, A, Bull. Nev. Agr. Exp. Sta.; B, Bull. Mich. Agr. Exp. Sta.)

SOLANACEAE, NIGHTSHADE FAMILY.
Horse Nettle (Solanum carolinense L.).

‘Berry orange-yellow, 1.6 to 2 cm. in diameter; seeds pale dull
yellow, much flattened, obovate, 2 to 3 mm. in length; finely granu-
lar, or indented over whole surface.

Black Nightshade (Solanum nigrum L.).

Berries black, globular, smooth; seed asymmetrically ovate, flat-
tened, pale yellowish brown, finely granular; diameter about
1.5 mm.

Buffalo Bur (Solanum rostratum Dunal.).

Black berry enclosed in spiny yellow calyx; seeds nearly circular,
bearing a dent on one side of the margin; flattened, pitted on the
surface; both sides irregularly indented with depressions; color,
dull dark brown; seed about 2.5 mm. broad.

Jimson Weed (Datura stramonium L.).

Seed one-eighth in. in length, brownish or blackish, kidney-shaped,
elliptical or nearly spherical, with numerous large depressions and
smaller pits; hilum with a small depression.

472 WEED FLORA OF IOWA

Figure 340B

Figure 340C Figure 340D

Fic. 340. A. Horse Nettle (Solanum carolinense). a, b, ec and d, different
' views of seed; e, fruit.

B. Black Nightshade (Solanum nigrum). a, two seeds, side view, enlarged; b,

group showing the natural size; c, a section of a seed, parallel with the

faces, showing the spirally curved embryo imbedded in the endosperm.

Buffalo Bur (Solanwm rostratum). a, prickly calyx; b, seeds with pits; ¢,

seed, natural size; d, cross section of seed with embryo.

D. Jimson Weed (Datura stramonium). a and b, seeds from different views;
between a and b, seeds, natural size; c, cross section of seed showing
embryo.

(After Hillman, A, C, D, Mich. Agr. Exp. Sta. Bull; B, Bull. Nev. Agr. Exp. Sta.)

Q

SCROPHULARIACHAEH, FIGWORT FAMILY.
Moth Mullein (Verbascum blattaria L.).

Seeds light to dark brown, 0.5 to 1 mm. in length, prismatic,
6-sided, base truncate, broader than the rounded apex; each side
face pitted in longitudinal rows.

Mullein (Verbascum thapsus L.).

Seeds columnar, 4-6-sided, top usually truncate, base nearly so;
one-thirtieth in. in length; faces deeply transversely pitted; surface
dull; color brown; scar in middle of flattened base. Reported as
frequently found in seeds of timothy and similar grasses.

THE GENERAL CHARACTERS OF SHEDS 473

Figure 341A Figure 341B

@
Se
ns
5 e
B G
a
Figure 341C

Fig. 341. A. Moth Mullein (Verbascum blattaria). A, a group of seeds, en-
larged, showing different forms, and kinds of surface markings. a, b and
ce were produced from seeds of V. blattaria, and d from V. thapsus. B rep-
resents a group natural size. C, a section taken lengthwise through the
center of a seed, showing the embryo and surrounding endosperm.

B. Common Mullein (Verbascum thapsus).

C. Toad Flax (Linaria vulgaris). A, a side view of a seed much enlarged, the
scar within the notch on the upper right-hand margin. B, a group show-
ing the natural size. C, a section through the center of a seed showing
the embryo.

(A, after Hillman, Bull. Mich. Agr. Exp. Sta:; B, drawing by L. R. Collins;
C, after Hillman, Bull. Mich. Agr. Exp. Sta.)

Toad-flax (Linaria vulgaris Hill.).

Seeds flattened, wing-margined, orbicular in outline, wing wavy,
notched at one end; one-twelfth in. in diameter; surface rugose ;
wings one-thirtieth to one-twenty-fifth in. wide; embryo slender,
eurved. Commonly occurs in grass seed and occasionally in clover.

Speedwell (Veronica peregrina L.).

Seeds oblong to egg-shaped, flattened, one-thirty-second to one-
thirtieth in. long, slightly curved, the outer face with a central
ridge; embryo straight, surrounded by the endosperm; raphe on
the inner face; scar projecting.

AT4 WEED FLORA OF IOWA

Fic. 342. Speedwell (Vernonia peregrina). a, b, d, different views of seeds; ¢,
seeds, natural size.
(After Hillman, Mich. Agr. Exp. Sta.)

PLAN TAGINACEAE, PLANTAIN FAMILY.
Bracted Plantain (Plantago aristata Mx.).

Seeds oval or oblong, back of seed convex with transverse ring
across the middle or nearly so, one-twelfth to one-eighth in. long;
inner face with white marginal ring, in center of inner face 2 pit-
like markings each surrounded by whitish area, ENTERS appearance
of 2 we or 2 links of a chain.

Figure 343A

Figure 343B Figure 343C

Fie. 343. Bracted Plantain (Plantago aristata). A, group of seeds. B and C,
the convex and grooved faces, respectively.
(A, after Hillman, Bull. Nev. Agr. Exp. Sta.; B and C, drawings by Char-
lotte M. King.)

THE GENERAL CHARACTERS OF SEEDS 475
Ribgrass, Buckhorn (Plantago lanceolata L.).

Seeds oblong, convex on back, one-twelfth to one-seventh in. in
length, edges folded inwardly to deep central longitudinal groove

Fic. 344. Buckhorn (Plantago lanceolata). A and B, group of seeds showing
both the convex and grooved faces. C, a sterile seed. D, a seed in cross
section. BH, seed showing the mucilage. IF, the natural size.
(After Hillman, Bull. Nev. Agr. Exp. Sta.)

on inner face; brown, smooth, shining; scar at center of ETON
frequently of dare color.

s

Dooryard Plantain (Plantago major L.).

Seeds oblong to trapezoidal in shape, usually 4-sided, some of
them 3-sided, one-twenty-second to one-sixteenth in. long; brown-
ish to black; surface bearing 5 ridges radiating from scar; scar on
middle of inner face, often with white markings.

Rugel’s Plantain (Plantago rugeliui Dene.).

Seeds oblong, rhomboidal, generally trapezoidal with flattened
edges, one-eighteenth to one-twelfth in. in length; color brownish to
black; surface minutely roughened, ridgelike markings absent; scar
circular, whitish.

476 WEED FLORA OF IOWA

Figure 345B

Fic. 345. A. Common Plantain (Plantago major). a, a group of seeds, en-
larged, showing the relative form and size, also the surface ridges as dark
lines; b, a group showing the natural size; c, a cross section of a seed.

B. Plantago rugelii. A, seeds, the upper two showing the scar. B, seed show-
ing the mucilage. C, a seed-vessel. D, seeds, natural size.

(After Hillman, Bull. Nev. Agr. Exp. Sta.)

RUBIACHAH, MADDER FAMILY.
Cleavers (Galwum aparine L.).

Fruit indehiscent, spherical, one-tenth to one-eighth in. in diam-
eter, roughened with prickles, tuberculate when prickles are rubbed
off ; color blackish ; embryo curved; endosperm horny; fruit covered
with hooked trichomes.

Fic. 346. Cleavers, or Bedstraw (Galium aparine).
(After Winton.)

THE GENERAL CHARACTERS OF SEEDS ATT

COMPOSITAE, COMPOSITE FAMILY.

Baldwin’s Ironweed (Vernonia baldwint Torr.).

Achenes practically indistinguishable from those of the follow-
ing species.

; Figure 347A Figure 347B

Fic. 347. JIromweed seeds. A. Vernonia fasciculata. B- Vernonia baldwini.
Achenes with pappus.
(Drawings Charlotte M. King.)

Ironweed (Vernonia fasciculata Mx.).

Achenes 3-3.5 mm. long, and 1 mm. broad; general form slender,
cylindrical, often slightly curved; strongly 9-10-ribbed, ribs of
same color as achene, pale brown; tuft of purplish brown pappus
bristles attached at larger end; length of pappus hairs 6 mm.

White Snakeroot (Hupatorium urticaefolium Reichard).

Achene long, 5-angled, prominently grooved between the angles
oue-twelfth to one-tenth inch; generally blackish except at the
base where it is yellowish; the scar at base with a small circular
opening, and whitish border; smoothish (see figure), pappus of fine
white capillary bristles; the upper part of beak expanded into
candelabra form, bearing the somewhat fragile pappus.

Joe-Pye Weed (Hupatorium purpureum L.).

Achenes smooth, prominently ribbed; 5-angled, truncate; about
one-eighth of an inch long; base white; pappus with numerous
tawny-colored, capillary bristles. Miss Mary Nichols, who studied
the achenial hairs of EH. villosum, finds that they are short with
lateral canals. The achenial hairs of H. purpureum, according
to Mr. Fracker, are simple, in H. villosum duplex.

478 WEED FLORA OF IOWA

xs

_ Figure 348A Figure 348B Figure 348C

“a

Fic. 348. Seeds of Snakeroot (Hupatorium urticaefolium) and Joe-Pyeweed
(Eupatorium purpureum). A. Eupatorium purpureum. B. Achenial hairs
of same. C. Hupatorium urticaefolium.

(A and C, drawings by Ada Hayden; B, drawing by S. B. Fracker.)

Figure 349 1 Figure 349 2

Fie. 349. 1. Hairs from achenium of Eupatorium villosum. 2. Surface of
achenium of Hupatorium urticaefolium.
(Drawings by S. B. Fracker.)

‘False Boneset (Kuhnia eupatorioides L.).

Achenes oblong, columnar, 10-15-ribbed ; blackish or reddish, base
with prominent disklike area marked by circular, somewhat bulging
ring; from one-eighth to one-tenth inch in length; pappus of
fine tawny colored capillary, somewhat brittle, bristles. The achenial
hairs of Kuhnia eupatorioides, according to Miss Mary A. Nichols,
are mostly simple and short; a few duplex hairs also occur.

Blazing-star (Liatris punctata Hook.).

Achenes 10-ribbed; slender, tapering to the base; one-quarter
to one-third inch long; grayish, pubescent, almost pilose; apex
brownish; scar at base indistinct; pappus or numerous plumose
bristles. The achenial hairs of Liatris gracilis, according to Miss
Nichols, are duplex with an indistinct wall arising from the base.
The hairs of L. punctata, according to Mr. Fracker, are duplex
and simple.

THE GENERAL CHARACTERS OF SHEDS 479

Figure 350A Figure 350B

Fic. 350. Seeds (achenes) of: A. Blazing Star (Liatris punctata). B. False
Boneset (Kuhnia eupatorioides).
(Drawings: by Ada Hayden.)

Figure 351A : Figure 351B

Fic. 351, Achenial_ hairs of: A. Kuhnia eupatorioides. B. Liatris punctata.
: (Drawings by Fracker.) ;

Broad-leaved Gum-plant (Grindelia squarrosa Dunal).

Achenes short, thickened, faintly 4-angled, with veins between
the angles; curved; one-twelfth to one-eighth of an inch in length;
straw-colored; apex truncate; base with light scar. The related
Bigelovia nudata, according to Mr. Fracker, has duplex hairs.

Canadian Goldenrod (Solidago canadensis L.).

Achenes minute, nearly terete, obovate, many-ribbed; brownish

or greenish, somewhat pubescent; pappus of numerous fine capillary
equal bristles. i

480 WEED FLORA OF IOWA

Figure 352A Fig. 352B Figure 352C

Figure 352C ‘Fig. 352D

Fic. 352. Seeds (achenes) of: A. Gum Weed (Grindelia squarrosa), enlarged
and natural size. The one at the top shows the wrinkled appearance of the
corky-thickened angles. B, Canadian Goldenrod (Solidago canadensis). C,
Stiff Goldenrod (Solidago rigida). D, Late Goldenrod (Solidago serotina).

(A, after Hillman, Bull. Nev. Agr. Exp. Sta.; C, drawing by Charlotte M. King;

B and D, drawings by Ada Hayden).

Stiff Goldenrod (Solidago rigida L.).

Achenes ribbed, somewhat 4-angled, with minute ribs between
the angles; scar at base small, whitish, one-sixth to one-twelfth in.
long, pale straw-colored; pappus of minute capillary bristles of
nearly equal size, spreading.

Late Goldenrod (Solidago serotina Ait.).

Achenes minute, somewhat teretish, many-ribbed, minutely pu-
bescent, straw-colored, one-twentieth in. in length; small obovoid
scar at base, whitish; pappus spreading, of fine white capillary
bristles.

THE GENERAL CHARACTERS OF SEEDS 481

Willow-leaved Aster (Aster salicifolius Ait.).

Achene slender, pale brown, about 1.5 mm. long and .25 mm.
broad ; 5 longitudinal ribs at angles of seed; pappus straw-colored,
hairs or bristles 6 mm. in iength. The achenial trichomes are long,
the duplex character very pronounced, according to Mr. Fracker.

Fig. 303A Fig. 353C Fig. 353D

Fig. 353. Seeds of Aster, Whiteweed and Horseweed. <A, Aster salicifolius. B,
Daisy Fleabane or Whiteweed (Hrigeron annuus). C, Horseweed (Hrigeron
canadensis). D, Whiteweed (Hrigeron ramosus).

-(A and B, drawings by Charlotte M. King; C and D, after Hillman; C, Bull.

Nev. Agr. Exp. Sta.; D, Bull. Mich. Exp. Sta.)

He found much variation in the trichomes of the genus. The hairs
of A. drummondu are shorter. The trichomes of A. tradescants
and A. macrophyllus are longer and more slender than in A. drum-
mondu. The duplex hairs of Aster laevis, A. oblongifolius, A. novae-
angliae and A. multiflorus are slender.

Fig. 354A Fig. 354B Fig. 354C Fig. 354D Fig. 354K

Fic. 354. Achenial hairs of Asters. A. Aster novae-angliae. B. Aster
Salicifolius. C. Aster tradescanti. D. Aster oblongifolius. EH. Aster
multiflorus.

(Drawings by Mary A. Nichols and S. B. Fracker.)

31

482 WEED FLORA OF IOWA

Daisy Fleabane (Hrigeron annuus (L.) Pers.).

Achenes pale straw color, smooth, shining, flattened, obovate;
length 0.7-0.9 mm.; the apex bears a row of small straw-colored
bristles.

Horseweed (Erigeron canadensis L.).

Achenes one-twenty-fourth to one-twentieth in. long, white or
whitish, oblong lance-shaped, much flattened, one side often more
convex than the other; scar of seed with small, whitish, raised

Fig. 355A Fig 355B Fig. 3550 Fig. 355D

Fic. 355. Achenial hairs of Asters and Bigelovia. A. Aster laevis. B. Aster
macrophyllus.. C. Aster drummondii. D. Bigelovia nudata.
(Drawings by Mary A. Nichols and S. B. Fracker.)

border, pubescent; pappus small, of numerous, fragile, capillary
bristles, usually breaking away. With grass seeds and lawn mix-
tures.

Cup Plant (Silphium perfoliatum L.).

Achenes large, two-fifths in. in length, dorsally flattened, 2-
winged, notched at apex, grayish or bronze-colored, margins thin.

Marsh Elder (Iva xanthifolia Nutt.).

Achenes obovoid, brown to black, with somewhat flattened longi-
tudinal faces 1.5 to 2 mm. in length, longitudinally striate with
fine markings.

Small Ragweed (Ambrosia artemisiaefolia L.).

Involucre containing a single achene one-twelfth to one-sixth in.
long, obovoid or globular, tipped by a tapering beak one-quarter
length of involucre; ridges several (4-10), prominent, with pro-
jecting tubercles, short, acute; color grayish or brownish, pubescent;

THE GENERAL CHARACTERS OF SHEDS 483

Fig. 356A Fig. 356B
Fie. 356. Seeds of Small Ragweed and Cup Plant. A. Single achene of Cup
Plant (Silphium perfoliatum).

B. Achenes, various views of Small Ragweed (Ambrosia artemisiaefolia) ; A,
five specimens having the outer covering, and showing the crown of teeth,
or spines; B, one having the covering partially broken away, exposing the
achene; C, achene, the covering persisting only at the base; D, a sectional
view of a fruit; E, a group showing the natural size.

(A, drawing by Ada Hayden; B, after Hillman, Bull. Nev. Agr. Exp. Sta.)

involuere reticulated, somewhat brittle, achene with thick, rather

hard wall; cotyledons 5, large, thick, fleshy, oily; caulicle short.
In clovers and alfalfa.

Lance-leaved Ragweed (Ambrosia bidentata Michx.).
Involucre top-shaped (turbinate), closed, yellowish or brownish;
length, exclusive of the spine, one-tenth to one-eighth in.; 1 very
prominent lobe and 6 or more prominent tubercles; surface of in-
volucre rough and hispid, pubescent.

Ww

Fig. 357A Fig. 357B Fig. 3570

Fic. 357. Seeds of some Ragweeds. A. Ambrosia bidentata. B. Ambrosia
psilostachya. C. Ambrosia trifida.
(Drawings, A, Charlotte M. King; B, Ada Hayden; C, after Hillman. Bull.
Mich. Exp. Sta.)

484 WEED FLORA OF IOWA

Western Ragweed (Ambrosia psilostachya DC.).

Bur teretish, one-eighth to one-fifth in. long, obovoid, with beak
less prominent than in preceding species; tubercles when present,
short; ridges 4-5; color grayish ; pubescent; involucre pitted, readily
removed leaving brown achenium, with short beak; cotyledons large,
fleshy, oily. In clover seed.

Large Ragweed (Ambrosia trifida L.).

Achene one-fifth to three-tenths in. in length, one-sixth in. across
at widest portion near upper end, containing seed one-fifth to three-
tenths in. long, or in extreme cases nearly one-half in.; width at
upper end 1.6 in., involucre obovate, narrow below, gradually
widening toward top, tipped by tapering beak; fruit prominently

Fig. 358A

Fig. 358B

Fic. 358. A. White-leaved Franseria (Franseria discolor). B. Franseria
Hookeriana. A, bur enlarged; B, natural size; C, bur cut lengthwise.
(A, drawings by Ada Hayden and Charlotte M. King; B, after Hillman, Bull.
Nev. Agr. Exp. Sta.)

ridged, forming rather long projecting tubercles, 4-10 in number,
near upper end; involucre pitted or marked by cross ridges; color
grayish or brownish; pubescent or nearly smooth; encloses a single
achene, commonly called seed; outer portions of achene blackish or
brownish; embryo with large thick cotyledons; seed oily, caulicle
thick, short. In uncleaned clover seed.

THE GENERAL CHARACTERS OF SHEDS 485

White-leaved Franseria (Franseria discolor Nutt.).

Involucre with burs from a little less than one-quarter in. to
slightly more in length, with 2 achenes, each in a separate cell,
oblong, with 2 pointed spines usually incurved at apex and tapering
base ; several prominent ridges; 3 or more tubercles, furrowed; light
straw color, surface pubescent; achene slightly reticulated.

Hooker’s Franseria (Franseria hookeriana Nutt.).

Involucre lanceolate or oval, two-fifths in. in length, with a promi-
nent conical spine and numerous, straight or recurved rigid spines,
variable in number, as long as the width of the bur; surface wrin-
kled ; involucre with one elongated achene; color yellowish, shghtly
pubescent. )

Cocklebur (Xanthium canadense Mill.).

Involucre containing 2 seeds; three-quarters to one in. or more
long, each in a separate cell, the lower placed further down in the
bur than the upper; bur hard, woody, thick-walled, bearing numer-
ous hispid recurved spines, the 2 spines at the end thicker, heavier,
and incurved; surface of achene blackish in color, thin-walled; and
embryo slender with 2 long cotyledons and a thick caulicle; each
seed cavity connects with a channel, frequently may also show
styles connecting with this channel; odor of seed strong.

Fig. 359A Fig. 359B

Fic. 359. Burs of Cockleburs. A. Common Cocklebur (Xanthium canadense),
with view of entire bur, and of cross section showing the pair of seeds in place.
B. Spiny Clotbur or Cocklebur (Xanthium spinosum).
(After Hillman, Bull. Mich. Agr. Exp. Sta.)

Cocklebur (Xanthium spinosum Kearney).

Involucre one-third to one-half in. long, cylindraceous, obtuse,
armed with short prickles, inconspicuous, 2-beaked, or pointless,
occasionally a single straight spine; bur oblong or somewhat flat-
tened ; surface sparingly covered with slender hooked prickles one-

486 WEED FLORA OF IOWA

twelfth in. long; color dull; smooth or covered with yellowish
hairs; achenes 2 in each bur.

Cocklebur (Xanthium strumarwm L.).

Involucre one in. long; brownish in color; prominently bristly
spines curved; achenes 2 in each bur; closely resembles X’. can-
adense..

Rough-Ox-eye (Heliopsis scabra Dunal).

Achenes thick, obtusely 3-4-angled, with truncate summit; one-
eighth to one-seventh in. long; margins pubescent; blackish; apex
somewhat depressed; scar at base light or straw-colored; pappus
none.

Ae

Fig. 360A Fig. 360A1L Fig. 360B Fig. 360C

Fic. 360. Seeds of Heliopsis and Rudbeckia. A, Al, Ox-eye (Heliopsis scabra).
B. Black-eyed Susan or Nigger-head (Rudbeckia hirta) ; a, two views of
achenes, b, achenes, natural size. C. Coneflower (Rudbeckia laciniata).

(A, C, drawings by L. Collins; Ai, Charlotte M. King; B, after Hillman, Bull.

Mich. Agr. Exp. Sta.)

Nigger-head (Rudbeckia lirta L.).

Achene purplish black, 1.5-1.8 mm. long, tapering slightly from
base to apex; a distinct ridge at each of the 4 angles of the achene;
each side with fine longitudinal strips; no pappus.

Cone-flower (Rudbeckia laciniata L.).

Achenes 4-angled, brownish, truncate, one-fifth in. long; min-
utely roughened; upper end with projecting truncate point; apex
with an inconspicuous sear.

Gray-headed Cone-flower (Lepachys pinnata Torr. & Gray).

Achene short, flattened or angular, one-tenth of an inch long, 2
slightly marginal wings, and 2 intermediate ‘ones, or only 1, convex;
apex whitish, depressed with slight projecting scar; base with

THE GENERAL CHARACTERS OF SEEDS 487

inconspicuous scar of nearly the same color as the rest of the
achene.

Sunflower (Helianthus annuus L.).

Achenes obovate, oblong, somewhat flattened, one-fifth to one-
quarter of an inch long; with appressed pubescence (see figure)
especially at upper end, grayish and mottled with brown; marked
by longitudinal lines; more prominent ridge in center; lower end
of achene notched, containing the scar; the apical scar with a
slightly elevated circular margin; cotyledons large and fleshy. The
achenes, according to Mr. Fracker, are long, slender, and duplex;
H. tuberosus has simple and several-celled trichomes but not duplex.
H. occidentalis has short, thick, duplex hairs.

Fig. 361A Fig. 361B Fig. 361C Fig. 361D

Fic. 361. Seeds of Cone-flower and Sunflower. A. Coneflower (Lepachys pin-
nata). B and C. Common Sunflower (Helianthus annuus). D. Meadow
Sunflower (Helianthus grosse-serratus).

(A, drawing by Ada Hayden; B and D, drawings by C. M. King; C, after

Hillman, Bull. Mich. Exp. Sta.)

Saw-toothed Sunflower (Helianthus grosse-serratus Martens).

Achenes oblong, narrowed at base and broad at apex, flattened,
with 2 edges, and 1 prominent ridge, sometimes 2 on each side;
one-sixth to one-fifth in. long; pappus of 2 lanceolate awns; smooth
or slightly hairy; brownish or lighter color, mottled with brown;
the scar at the end is in the form of a small notch; the remnant
of a corolla tube at the apex; cotyledons fleshy.

Prairie Sunflower (Helianthus petiolaris Nutt.).

Achenes obovate-oblong, but slightly flattened, villous pubescent,
(see figure), a prominent longitudinal ridge and several lines on
each side; grayish, mottled with brown; scar in notch at the lower
end; scar on upper end cireular; cotyledons 2, large and fleshy.
According to Mr. Fracker, the achenial hairs are long and slender
and duplex.

488 WEED FLORA OF IOWA

Fig. 362A Fig. 362B

Fic. 362. Seeds of Sunflowers. A. Prairie Sunflower (Helianthus petiolaris).
B. Wood Sunflower (Helianthus strumosus).
(Drawings by L. R. Collins.)

Wild Sunflower (Helianthus strumosus L.).

Achenes obovate, flattened, several fine lines and a longitudinal
ridge on each side, one-sixth to one-fifth in. long, nearly glabrous:
yellowish or light brown, finely mottled, except near apex and base
which are lighter in color; lower end marked by small distinct
sear, occurring in a notch; upper end bearing large circular scar;
cotyledons 2, large, fleshy.

Fig. 363B Fig. 363C Fig. 363D

Fic. 368. Achenial hairs of Sunflower seeds. A. Artichoke (Helianthus tuber-
osus). B. Prairie Sunflower (Helianthus occidentalis). C.. Common Sun-
flower (Helianthus annuus). D. Prairie Sunflower (Helianthus petiolaris).

(Drawings by S. B. Fracker.) y

THE GENERAL CHARACTERS OF SEEDS 489
Spanish Needles (Bidens bipinnata L.).

Achenes exclusive of awns one-half to three-fifths in. long, linear,
4-angled, slightly pubescent; pappus consisting of usually 4 diver-
gent downwardly barbed awns, lighter in color than the achene;
base of seed with a lightish ringed border and a small depression.

Fig. 364A Fig. 364B

Fic. 364. A. Seeds of Spanish Needles, Pitchforks, or Bootjacks. a, Spanish ©
Needle (Bidens frondosa), b, Bidens bipinnata.
B. Bidens discoidea.
(Drawings by Charlotte M. King.)

Small Stick-tight (Bidens discoidea (T. & G.) Britton).

Achenes small, flat, narrowly acuminate, upwardly strigose;
pappus of upwardly hispid, rarely downwardly barbed awns.

Beggar-ticks (Bidens frondosa L.).

Achenes flattened, oval or obovate, three-tenths to two-fifths. .
inch exclusive of the awns; slightly ciliate on the margins (see
figure); awns generally diverging, downwardly barbed; corolla
tube, whitish, with small opening in the center; basal portion of
achene with a prominent depression with a light border. The
achenial hairs, according to Miss Mary A. Nichols and Mr. Fracker,
are duplex. In B. cernua they are simple. The related species
(B. aristosa) formerly called Coreopsis has duplex hairs, although
some hairs are simple.

490 WEED FLORA OF IOWA

=>

Fig. 365A

i!
1
\

.

Fig. 3650

Fic. 365. Achenial hairs of Beggar-ticks. A. Bidens frondosa. B. Bidens
cernua. C. Bidens aristosa.
(Drawings by Mary A. Nichols.)

Sneezeweed (Helenium autumnale L.).

Achenes straw-colored, with several longitudinal ribs, length 1
mm., breadth 0.3 mm. at apex, toward which the achene widens;
surface bears scattered appressed hairs; pappus several chaffy
points on margin of truncate apex.

Fetid Marigold (Dyssodia papposa (Vent.) Hitche.).

Achene slender, 4-angled; length 3 mm., width at truncate apex
.75 ram.; black, with numerous, scattered, appressed black hairs;
pappus a row of chaffy scales, dividing into numerous, rough,
bristly hairs; 3 mm. long. According to Mr. Fracker, the achenial
hairs are simple and duplex, the tip in duplex hairs deeply cleft.

THE GENERAL CHARACTERS OF SEEDS 491

Fig. 366A Fig. 366B Fig. 366C

Fic. 366. Seeds and achenial hairs of Sneezeweed and Fetid Marigold.’ A.
Sneezeweed (Helenium autumnale). B. Fetid Marigold (Dyssodia papposa).
C. Achenial hairs of Fetid Marigold.

(A and B, drawings by Charlotte M. King; C, from drawing by Mary A. Nichols.)

Yarrow (Achillea millefolium L.).

Achenes one-twelfth to one-tenth in. long, oblong to obovate,
somewhat compressed; light on the margin, the remainder some-
what brownish; sometimes slightly curved, base with prominent scar
with slightly raised border; apex larger with a notch in the center
‘and a projecting knob; surface of the achene marked with fine
lines ; pappus absent.

A
Fig. 367A Fig. 367B

Fic. 367. Seeds of Yarrow and Mayweed.! A, Yarrow (Achillea millefolium) ; a
seeds (achenes) in side view, the two at the left showing the minute, cir-
cular sear; b, group showing the natural size.

B. Mayweed (Anthemis cotula); a, a group of seeds showing the prevailing
forms; b, a group showing the natural size.

(After Hillman, Bull. Nev. Agr. Exp. Sta.)

Mayweed (Anthemis cotula L.).

Achenes one-twentieth to one-sixteenth in. long, oblong with
preminent tubercled ribs, or occasionally smoothish curved, the base
tipped with smooth nipple-like projections; pappus absent; straw-
colored to light brown; bearing a projection scar; base with round,
light-colored sear. Common in clover and grass seeds.

492 WEED FLORA OF IOWA

Ox-eye Daisy (Chrysanthemum leucanthemum L.).

Achenes flattened, club-shaped, straight or slightly curved, one-
twentieth to one-tenth in. long, oblong; angles white, with brown
interstices ; 5-10-ribbed ; small scar at basal end; pappus wanting.

Fic. 368. Seeds of Ox-eye Daisy (Chrysanthemum leucanthemum). A, pre-
vailing forms of seeds (achenes); B, one in cross section; C, a group
showing the natural size. ‘

(After Hillman, Bull. Nev. Agr. Exp. Sta.)

Wormwood (Artemisia biennis Willd.).

Achenes brown, smooth, from 3-4 flattened faces, angled between
longitudinally ; length .£8 mm., width .3 mm., broader at apex than
at base.

2 x a
. oe ~
~ ~ eo 4 =
.
. a 4
b b
Fig. 369A Fig. 369B

Fic. 369. Seeds of Wormwood and Fireweed. A. Wormwood (Artemisia
biennis) ; a, achenes, b, natural size.
B. Fireweed (Hrechtites hieracifolia) ; a, achenes, b, natural size.
(After Hillman, Bull. Ney. Agr. Exp. Sta.)

Fireweed (Hrechtites hieractfolia (L.) Raf.).

Achene linear-oblong, straight, or curved, prominently striate,
pubescent, beakless, one-sixth in. in length; upper end with a white
ring, within the ring a slight depression; scar at the lower end with
whitish ring, and a small depressed opening; pappus of numerous
white soft, capillary bristles.

THE GENERAL CHARACTERS OF SEEDS 493
Indian Plantain (Cacalia tuberosa Nutt.).

Achenes oblong, straight, or slightly curved, one-fifth in. in
length; brown; prominently ribbed, the ribs minutely roughened ;
the apex of the seed with a slightly projecting rim or border to
which the pappus is attached; the base with a circular ring; pappus
with numerous fine, white, capillary bristles.

Fig. 370A Fig. 370B

Fic. 370. Seeds of Indian Plantain and Groundsel. A. Indian Plantain (Cacalia
tuberosa). B. Groundsel (Senecio vulgaris).
(Drawings by Charlotte M. King.)

Groundsel (Senecio vulgaris L.).

Achenes teretish or those of marginal flowers compressed, narrow,
eylindrical; 5 or 10-ribbed, pubescent; one-half in. long; upper
part expanded, extending beyond narrow portion of upper part of
achene; lower portion with a depression; color reddish; pappus of
fine, white, capillary bristles.

Burdock (Arctium lappa L.).

Achenes 3-5-ridged, upper portion truncate, one-fifth to one-
fourth in. long, compressed or oblong, nearly straight to slightly
eurved, 3-angled; surface mottled in appearance, due to the small
serrulate scales with projecting tips of ridges beyond the border;
scar surrounded by a circular lighter colored area; scar at base
lighter in color; pappus of numerous short scales. In commercial
seeds, occasionally.

494 WEED FLORA OF IOWA

74

Fic. 871. Seeds of Burdock (Arctium lappa). a, a side view of one of the inner
achenes of a bur; b, showing the inner surface of a curved, outer achene,
and exhibiting the character of the apex, both enlarged; c, a group show-
ing natural size.

(After Hillman, Bull. Nev. Agr. Exp. Sta.)

Tall Thistle (Cirsium altissimum Willd.).

Achenes lanceolate-obovate, tapering toward lower end, and some-
what narrowed toward the apex, wider in the middle, one-eighth in.
in length; width one-twelfth in.; dull brown or grayish excepting
light colored ring at upper end; numerous fine ridges; apex con-
cave, with the remnant of corolla tube projecting from the center;
color uniform; not marked by light and dark areas as the bull
thistle.

Fig. 372A Fig. 373B

Fic. 372, Seeds of Thistles. A. Different views of Canada Thistle (Cirsium
arvense). B. Bull Thistle (Cirsium lanceolatum).
(Drawings by Charlotte M. King.)

Canada Thistle (Cirsium arvense (L.) Scop.).

Achene lanceolate, narrowed at lower end, tapering from some-
what thickened top, one-twelfth to one-eighth in. long; the eup-
shaped top with a projecting conical portion, straight or slightly
curved; marked with longitudinal dark lines or furrows; apex
with a light colored border, giving appearance of a ring. Found in
seed of small grains, clovers and grasses.

THE GENERAL CHARACTERS OF SEEDS 495

Field Thistle (Oirsiwm discolor (Muhl.) Spreng.).

Achenes obovate, inner edge nearly straight, outer curved, convex ;
one-seventh to one-sixth in. long, tapering from narrowed base
to apex, upper part longitudinally striated, slightly pigmented ;

Fic. 373. Seeds of Thistle. 3. Cirsium altissimum. 4. Cirsium discolor. 5.
Cirsium undulatum. 6. Cirsium ioense.
(Drawing by Charlotte M. King.)

grayish, upper part yellowish for one-third length of the achene.
Found in seed of alfalfa and red clover.

Towa Thistle (Cirsium ioense (Pammel) Fernald).

Achenes obovate, lanceolate, one side of seed straight, outer side
slightly convex, one-fifth to one-fourth in. long, one-twelfth to, one-
sixteenth in. in width, gradually tapering from lower end toward
upper end, prominently widened just below the apex, marked by
longitudinal striations and dark areas, upper part yellowish, promi-
nent rim glossy; apex concave, with the prominent projecting rem-
nant of flower center.

Bull Thistle (Cirsium lanceolatum (.) Hill).

Achene lanceolate, curved, tapering, in many cases somewhat
angular, one-eighth to one-sixth in. long; brownish, not darkly
striated, marked with definite grooves, upper part lighter, ringed,
also showing at center of concave apex; apex with projecting point.
Found in red clover and in alfalfa seed.

Waivy-leaved Thistle (Cirsium undulatum (Nutt.) Spreng.).

Achene in general outline lanceolate, tapering from base, inner
edge slightly convex, several prominent ridges, light brown, not
pigmented; upper part yellowish; apex with prominent rim and
prominent remnant of corolla tube; achene slightly thicker than
that of C. discolor. Found in seeds of red clover and alfalfia.

496 WEED FLORA OF IOWA
Chicory (Cichorium intybus L.). -

Achenes oblong, ribbed, 5-angled, spotted, grayish or straw-
colored, with darker spots, one-twelfth to one-eighth in. in length
apex with the base of the pappus scales extending beyond the scar;

Fic. 374. Chicory (Cichorium intybus). A, B, two views of seeds; C, seeds,
natural size.
(After Hillman, Bull. Mich. Agr. Exp. Sta.)

minutely, transversely roughened ; base of seed lighter in color, with
small depressed scar; achenes from the inner part of the flower more
slender and straight than from outer part. Found with various
commercial seeds.

Corn-flower (Centaurea cyanus L.).

Achene oblong or obovoid, compressed, one-sixth to one-fifth in.
long; smooth, shining; with inconspicuous veins or nerves; lower
part of achene oblique; ivory-white; the elliptical or somewhat cir-
cular scar at base with whitish rimmed border, depressed, made up
of soft tissue; pappus of several series of scaly bristles; brownish
in color. The achenial trichomes, according to Mr. Fracker, are
long and simple.

Barnaby’s Thistle (Centaurea solstitialis L.). -

Involucre ovoid, 1.5 cm. in diameter, with stout straw-colored
spines, widely spreading ; achene cream or pale brown after matted;
length 2 mm., scar of attachment in a notch above rounded base;
apex truncate, bearing tubercle in the center.

THE GENERAL CHARACTERS OF SEEDS 497

Fig. 375A Fig. 375B é Fig. 375C

Wie. 375. Seeds of Corn-flower and Knapweed. A. SBarnaby’s Thistle or
Knapweed (Centaurea solstitialis); a, achene with pappus, ¢c, pappus re-
moved, b and d, achenes, natural size.

B. Corn-flower (Centaurea cyanus). C. Achenial hairs of Corn-flower.
(A, after Hillman, Bull. Nev. Agr. Exp. Sta.; B, after Nobbe; C, drawing by
S. B. Fracker.)

Bristly Ox-tongue (Picris echioides L.).

Achene elliptical, narrowed at base, with projection at tip ; one-
tenth in. in length; light brownish red; wrinkled transversely, espe-
cially toward apical end. Found in seed of alfalfa and clover.

Oyster Plant, Salsify (Tragopogon porrifolius L.).

Achenes linear, terete, beaked or long, covered with scalelike
tubercles on the ribs, or merely roughened, light straw-colored or
darker pappus of numerous plumose bristles; small scar at apex,
whitish with a depression scar at base with an oval depression.
Reported as a “‘weed of alfalfa meadows.”’

Meadow Salsify (Tragopogon pratensis L.).

Achenes linear, terete, one-half in. or little more long, exclusive
of beak; scar at base, whitish, with an oval depression; beak one-
third in. long; scar at end of beak whitish, with a depression,
striate, smooth or slightly roughened, light straw-colored or darker ;
pappus of numerous soft, brownish, plumose bristles.

: 382

498 WEED FLORA OF IOWA

es. —

SS

===

SOR
ae Eo
ee ee .

aos
St
Cant saa

x

ENS

et

a
Raabe

eit

Fig. 376A Fig. 376A1 Fig. 376B Fig. 376C
Fic. 376. Seeds of Picris and Tragopogon. A and Al. Bristly Ox-tongue
(Picris echioides). B. Oyster Plant (Tragopogon porrifolius) ; a, achenes
enlarged, b, achenes natural size.
C. Meadow Salsify (Tragopogon pratensis).
(A, drawings by L. R. Collins; B, after Hillman, Bull. Mich. Agr. Exp. Sta. ;
C, drawing by C. M. King.)

Dark-seeded Dandelion (Taraxacum erythrospermum Andrz.).

Achenes one-sixth to one-fifth in. long; lance-shaped, or spindle-
shaped, 5 longitudinal ridges, upper end with rough tubercles, per-
sistent long beak about two-fifths in. long, brownish, somewhat
pointed, prominently ribbed; pappus of numerous capillary, fragile,
white bristles ; color reddish ; toothed at apex; beak and pappus both
shorter; achenes more prominently tubercled than in 7’. officinale.

Sor >,

=<

i

Fig. 377A Fig. 377B

Fic. 377. Dandelion seeds. A. Red Seeded Dandelion (Taraxacum erythros-
permum) ; a, seed enlarged, b and c, seed, natural size, c, with pappus.

B. Common Dandelion (Taraxacum officinale).- A, an enlarged view of one
of the two similar faces of an achene, in which no attempt is made to show
the minute surface-scales which are not evident under the ordinary lens.
B, a group of seeds, natural size. b, one bearing the beak and pappus. C,
a group showing common variation in the form of the achenes.

(After Hillman: A, Bull. Mich. Agr. Exp. Sta.; B, Bull. Nev. Agr. Exp. Sta.)

THE GENERAL CHARACTERS OF SHEDS 499

Dandelion (Taraxacum officinale Weber).

Achenes two-fifths in. long including persistent beak, fusiform in
shape, prominent ribs, and projecting teeth at ribs, especially at
upper end; beak four-fifths to one in. in length; achenes light gray in
color, otherwise like preceding; pappus capillary, whitish, fragile.
With grass seeds.

Field Sow Thistle (Sonchus arvensis L.).

Achenes dark reddish brown, dull, ends slightly truncate, length
2.5-3 mm., width 0.8 mm., somewhat flattened, with 4 strong ribs or
angles, between which lie smaller ridges ; numerous transverse ridges
on the ribs.

Fig. 378C

Fic. 378. Seeds of Sow Thistles. A. Field or Perennial Sow Thistle (Sonchus
arvensis) ; B, natural size, showing pappus on one achene,
B. Sonchus oleraceus, different views of achenes.
C. Sonchus asper, A and B, different views of achenes, C, achenes, natural size.
(After Hillman, Bull. Mich. Agr. Exp. Sta.)

Spiny Sow Thistle (Sonchus asper Vill.).

Achenes broadly oblong or lance-shaped, similar faces, many-
ribbed, one-tenth in. long, slightly pubescent, prominent ridges
minutely roughened; base with a minute sear, brownish; the apex
with projecting point and fine, capillary, white, bristles. Found
with grass seeds.

500 WEED FLORA OF IOWA

Sow Thistle (Sonchus oleraceus L.).

Achenes light brown, flattened, ribbed, the prominent ribs rough-
ened; one-eighth in: long; pappus of white capillary bristles, much
like the preceding. ‘‘Apt to occur among grass seeds.’’

Wild Lettuce (Lactuca canadensis L.).

Achene three-twentieths in. in length, straight or curved, sides
somewhat unequal, transversely wrinkled, blackish brown, beak one-
twentieth in. long, shorter than in L. floridana; one faint rib on each
side of prominent midrib; decidedly convex on each side of midrib
to the flattened margin ; scar with whitish ring and small depression ;
pappus white, capillary. Much like ZL. floridana, beak smaller and
shorter. With commercial seed.

Fig. 379A Fig. 379B

Fic. 379. Seeds of Lettuce. A. Lactuca canadensis; a, enlarged achene, b,
natural size. B. Lactuca floridana.
(A, after Hillman, Bull. Mich. Agr. Exp. Sta.; B, drawing by Charlotte M. King.)

False Lettuce (Lactuca floridana (l.) Gaertn.).

Achene brown, transversely wrinkled, three-twentieths to seven-
fortieths in. in length, straight or slightly curved; beak light
brown, about one-fifth in. long, generally persistent, convex; ribs
rather faint, 1 on each side of prominent midrib, strongly convex
on each side of midrib, margin flattened; pappus white, capillary.

Prickly Lettuce (Lactuca scariola var. integrata Gren. & Godr.).

Achenes brownish, margin somewhat lighter, surface roughened,
one-ninth to one-sixth in. long; beak one-tenth to one-eighth in. long,
lance-shaped, straight or slightly curved, upper end tapering

THE GENERAL CHARACTERS OF SEEDS fe 501

v
BS

Dp

~
(

Fig. 380A Fig. 380B

Fic. 380. Lettuce Seeds. A. Lactuca scariola; A, side view of an achene, en-
larged. B, a group of the same, natural size. C, an achene bearing its
beak and fragile pappus.

B. Prickly Lettuce (Lactuca scariola var. integrata.)
(A, after Hillman, Bull. Nev. Agr. Exp. Sta.; B, drawing by L. R. Collins.)

toward the beak, somewhat flattened, on one side margined, faces
convex, with 5-7 longitudinal nerves; scar circular, with a small
depression.

Rattlesnake Root (Prenanthes alba L.). .

Achene oblong or columnar, truncate, somewhat flattened, 4-5
angled, brownish; upper part with a projecting ring to which the
bristles of pappus are attached; scar at the base whitish, not prom-
inent; one-eighth in. in length; pappus tawny.

Fig. 381A Fig. 381B

Fic. 381. Seeds of Rattlesnake Weed and False Calais. A. Rattlesnake Weed
(Prenanthes alba). B. False Calais (Agoseris cuspidata).
(Drawings by Charlotte M. King.)

502 WEED FLORA OF IOWA

False Calais (Agoseris cuspidata (Pursh.) Steud.).

Achenes fusiform, slightly contracted at the apex, with 10
prominent ribs; one-half in. long, or little longer; pappus of soft,
white, capillary bristles; scar at base, whitish, with a small opening.

Orange Hawkweed (Hieraciwm aurantiacum L.).

Achene oblong, columnar, one-tenth in. long; blackish or dark
brown, marked with prominent longitudinal ridges, minutely
roughened; base of achene with small circular raised border, lighter
than remainder of achene; pappus of numerous somewhat brown-
ish bristles, frequently breaking away near the top of the achene,
then showing short bristles.

Fig. 382A Fig. 382A1 Fig. 382B

Fic. 382. Seeds of Hawkweeds. A and Al, Orange Hawkweed (Hieracium
aurantiacum). B, Hawkweed (Hieracium canadense).
(A, after Hillman, Bull. Mich. Agr. Exp. Sta.; Al, drawing by L. R. Collins;
B, drawing by Charlotte M. King.)

Hawkweed (Hieracium canadense Mx.).

Acheres one-tenth to one-eighth in. long, oblong, columnar,
10-15-ribbed; blackish or reddish; base with prominent disklike
area marked by circular ring; apex with somewhat fine tawny-
colored capillary bristles; below point of attachment is an area
bulging outward; capillary bristles have tendency to break.

CHAPTER III.

MICROSCOPIC STRUCTURE OF
SOME WEED SEEDS

By
L. H. PAMMEL
and

CHARLOTTE M. KING

CHAPTER II.

-GRAMINEAE,* GRASS FAMILY.

Smooth Crab Grass (Digitaria humifusa Pers.).

A cross section of seed shows but slight development of the
pericarp and testa. The epidermal cells of the former are smaller
than the underlying rows of cells of the wall of the ovary. The
testa is reduced to a single layer of cells, longer than broad. The
aleurone layer is filled with protein grains. The starch cells of
the endosperm are larger and densely packed with polygonal
grains.

Fic. 383. Structure of the grain fruits of some Grasses (Gramineae).

I. Wild Barley (Hordeum jubatum). II. Timothy (Phleum pratense). III.
Smooth Crab Grass (Digitaria humifusa). IV. Sandbur (Cenchrus tribu-
loides). V. Millet (Setaria italica). VI. Corn (Zea mays). VII. Barn-
yard Grass (Echinochloa crusgalli).

t=testa. al=aleurone. en=endosperm. n=nucellus.
(Drawings by L. H. Pammel.)

ae,
*The material for this family has been taken from the accounts by Pammel
and Winton.

506 WEED FLORA OF IOWA

Broomecorn Millet (Panicum miliaceum L.).

The walls of the ovary are similar to those of Digitaria humifusa
except that they are wider. The testa is much compressed and
consists of several layers of small cells. The cells of the aleurone
layer are small, somewhat longer than broad. The cells of the
starch layer are similar to those of D. humrfusa.

Barnyard Grass (Echinochloa crusgalli (l.) Beauv.).

The adherent glumes in this species consist of several rows of
parenchyma cells, the inner portion, of one row of thick-walled
sclerotic cells with pore canals. The cells of the pericarp and testa
are much as in the other species, thin-walled and compressed. The
protective features are preserved in the coriaceous glumes. The
starch and aleurone layers are similar to those of Digitaria
humifusa.

Hungarian Grass or Millet (Setaria italica (L.) Beauv.).

The colorless smooth pericarp is but slightly thickened and con-
sists of three or four rows of elongated cells. These in colored
seeds contain the pigment. The testa is but slightly developed.
The cells of the aleurone layer are not much longer than broad,
and are densely filled with protein grains.

Green Foxtail (Setaria viridis (L.) Beauyv.).

Dr. A. L. Winton describes the microscopic structure as follows: ~

Empty Glumes and Glume of Sterile Flower. The lower empty
glume is three-nerved and less than 1 mm. long; the upper empty
glume and the glume of the staminate flower are five-nerved and
2 mm. long. In microscopic structure the three are practically
identical. 1. Outer Epidermts. Characteristic of this layer are
the elongated cells with sinuous side walls and longitudinal rows
of pits so arranged that one pit occurs in each concave bend of
the wall. On the middle portion of the mature glume each of
these pits is so large that it fills completely the bend of the wall,
and in addition has a thickened border, half of which coincides with
the cell wall, thus giving the tissue a lacelike appearance. This
structure is optically delusive, the pit borders often appearing to
be the cell walls, but is resolved by careful focusing and comparison
with the tissue in earlier stages of growth. In addition to these

MICROSCOPIC STRUCTURE OF WEED SEEDS 507

Fic. 384. Green Foxtail (Setaria viridis). I, spikelet with ripe fruit. g', lower
empty glume; g%, upper empty glume; gf, glume, and p', palet of the
staminate flower; ef?, glume, and p?, palet of fertile flower; c, caryopsis; b,
bristles. II and III. caryopsis enclosed by flowering glume and palet. X 8.

(After Winton, Conn. Agr. Exp. Sta.)

elongated cells, pairs of short cells, one isodiametric, probably a
hair-scar, the other more or less crescent-shaped, occur here and
there, and less frequently stomata and thin-walled one to three-
jointed hairs. 2. Mesophyl. Only about the nerves and the basal

Fig. 385A. Fig. 385B

Fic. 385. Green Foxtail. A. Outer epidermis of the staminate flower; I, at
the edge; II, in the middle. X 300.

B. Outer epidermis of the glume of the fertile flower, showing the wrinkled
central portion and the smooth edge.
(After Winton, Conn, Agr. Exp. Sta.)

508 WEED FLORA OF IOWA

portions of the glumes is this coat evident. It has no diagnostic
importance. 3. The Inner Epidermis is composed of elongated cells
with straight walls.

Palet of Staminate Flower. Within the glume of the staminate
flower is the palet, a hyaline scale only 1 mm. or less long with
a notch at the end. In general structure, it is much the same
as the other thin envelopes, but the cell walls are thinner.
1. Outer Epiderms. The narrow, elongated cells are wavy in out-
line, but pits are lacking or are indistinct. Isodiametric cells are
thin-walled; jointed hairs also occur. 2. Inner Epidermis. Except
at the base, where traces of mesophyl are sometimes evident, the
inner epidermis immediately underlies the outer epidermis.

Glumes and Palet of Perfect Flower. Both the glume and the
palet of the fertile flower closely envelop the grain at maturity,
the former being strongly convex, the latter flat except on the
edges, which clasp about the caryopsis. At the time of flowering
these envelopes are thin and of a green color, but at maturity they
are coriaceous, silicified and of a brown or mottled color. Under
the lens, numerous transverse wrinkles are evident on the glume
and on the middle or flat portion of the palet, the lateral portions
of the latter which clasp the caryopsis being smooth and shining.

1. Outer Epidermis. Throughout the glume and on the middle
portion of the palet, the cells are isodiametric or moderately elon-
gated and are arranged not only in longitudinal rows but also in
irregular transverse rows, the wrinkles being formed by the out-
bending of the cells at the end walls and the inward bending
half way between. At the time of flowering, it may be seen that
at the outer surface the end walls are sinuous and the side walls
are compoundly sinuous, but farther inward the end walls are
nearly straight and the side walls are simply, not compoundly
sinuous. At the end of each cell nearest the apex of the envelope,
a cuticular wart bearing a group of pits is usually evident, par-
ticularly on the palet. About these warts the adjoining end walls
are more or less curved and the side walls are not so deeply sinuous.
At maturity the cell cavity beneath the wart is conspicuous (on
the palet nearly circular), but at the other end of the cell is nar-
row or not evident at all owing to the encroachment of the strongly
thickened walls. The cell contents during the early stages of devel-
opment are colorless, but later on usually become dark brown. The
epidermal cells on the lateral or smooth portions of the palet which

MICROSCOPIC STRUCTURE OF WEED SEEDS 509

Fic. 386. Green Foxtail. Outer epidermis from the middle of the glume of the
fertile flower. I, outer surface, and II, inner surface soon after blooming.
III, outer surface when in fruit. X 300.
(After Winton, Conn. Agr. Exp. Sta.)

elasp about the caryopsis are longer, narrower, and less complex
than those already described. At maturity the wrinkles are usually
from 0.03 to 0.06 mm. apart. 2. The Hypodermal Fibers may be
readily isolated by treatment on the slide with caustic alkali. They
vary in length up to 0.6 mm. and are often toothed at margin.
3. Mesophyl. Rectangular parenchyma cells without intercellular
spaces make up this layer. Numerous chlorophyl granules are
present at the time of flowering. 4. The Inner Epidermis is com-

510 WEED FLORA OF IOWA

posed of rectangular cells resembling those of the mesophyl. Both
of these layers become more or less obliterated at maturity and are
of no diagnostic importance.

Pericarp. The ventral side is flat and has a darker colored spot,
the remains of the hilum, near the base. Extending half way from
the base to the apex on the dorsal side is a groove, which marks
the position of the embryo. Vogl describes minutely the histology
of the caryopsis of common millet (Panicum miliacewm L.) and

Fic. 387. Green Foxtail. Outer epidermis from the edge of the glume of the
fertile flower. X 300.
(After Winton, Conn. Agr. Exp. Sta.)

states that German millet (Setaria panis Jessen) has practically
the same structure. I find that his description applies also to the
caryopsis of both green and yellow foxtail. 1. Epidermis. As in
the outer epidermal layers of the floral envelopes the cells are
elongated and wavy in outline. On the dark colored spot already
referred to, the epidermal cells are more or less rectangular.

2. The Cross-Cells are similar to the tube-cells in form but are
usually shorter, broader, and more irregular in shape. 3. Tube-
Cells. These are 0.002 to 0.004 mm. wide and often reach the
length of 0.3 mm. a. Nucellar or Hyaline Layer. After treatment
with alkali, this layer is clearly seen in surface view. The cells
are of large size and have beaded walls. b. Endosperm. 1. Alewrone
Layer. The cells vary in diameter from 0.01 to 0.02 mm.

MICROSCOPIC STRUCTURE OF WEED SEEDS 511

2. Starch-Cells. Polygonal starch granules with conspicuous hilums
fill the parenchyma cells of the endosperm. In the outer layers
they are from 0.004 to 0.008 mm. in diameter but farther inward
they reach the maximum diameter of 0.018 mm. After dissolving
the starch with potash, there remains a network of threads con-
taining conspicuous granules. In this respect, however, this fruit
cannot be distinguished from the fruits of S. glauca Beauv.,
S. panis Jessen, Panicum miliaceum L. (see Vogl) and all the
other species of Panicum which I have examined. Detection m
Powder Form. The membranous glumes with pores in the bends of

Fic. 388. Green Foxtail. Transverse section of caryopsis. F, pericarp con-
sisting of the epidermis ep and the tube-cells sch; N, nucellar layer; H,
endosperm consisting of the aleurone-cells al and the starch cells s. X 300.

(After Winton, Conn. Agr. Exp. Sta.)

the walls and the coriaceous, transversely wrinkled, more or less
spotted, envelopes of the fertile flower with compoundly sinuous,
thickened cell walls are highly characteristic of both green and
yellow foxtail. These tissues are usually present in all stages of
development. The fruit elements are like those of common millet
and German millet. Treatment with caustic alkali brings out the
structure of the fruit coats and nucellar layer, and serves to dis-
tinguish this fruit from the common cereals. The starch is hardly
distinguishable from the starch of bindweed.

Dr. A. L. Winton describes the microscopic character of yellow
foxtail (Setarta glauca Beauv.) as follows:

The fruit of this species is larger than that of green foxtail, the
envelopes are also proportionately larger (with the’ exception of
the upper empty glume which is but half the length of the

512 WEED FLORA OF IOWA

spikelet) and the wrinkles on the glume of the fertile flower are
more pronounced. In microscopic structure the fruits of the two
species are identical. The floral envelopes are also much alike,
the only distinction being in the distance apart of the wrinkles on
the mature flowering glumes. In green foxtail this distance is
usually from 0.03 to 0.06 mm., but in yellow foxtail it is often
from 0.08 to 0.12 mm. Since this distinction does not apply to
the mature glumes and since the wrinkles on the palets of the two
species are practically the same, it is often difficult to identify the
species in ground mixtures. Fortunately, identification of the
genus is all that is usually required.

Fic. 389. Green Foxtail. Caryopsis in surface view. Significance of letters.
same as in Fig. 388.
(After Winton, Conn. Agr. Exp. Sta.)

Broom Corn (Andropogon sorghum var. technicus Koern).

Dr. A. L. Winton describes the microscopic structure of the
pericarp and testa of broom corn as follows: “As

Empty Glumes.—Both glumes are from 4 to 6 mm. long, equal-
ing and closely enveloping the fruit. They vary in color from
yellow-brown to red-brown. The soft hairs, which nearly cover
the outer surface, are loosely attached and most of them are re-
moved during the threshing and cleaning of the seed, leaving the
glumes smooth and shining. 1. The Outer Epidermis consists of
strongly sclerenchymatized cells several times as long as they are
broad, with wavy contour, interspersed here and there with iso-
diametric hair-scars, each accompanied by a crescent-shaped cell

MICROSCOPIC STRUCTURE OF WEED SEEDS 513

Fig. 390. Broom-corn. Fruit with chaff. r, two staminate spikelets; g1, lower
empty glume; g2, upper empty glume; g%, glume of rudimentary flower; gf,
flowering glume with awn; p, palet; ec, caryopsis. X 4.

(After Winton, Conn. Agr. Exp. Sta.)

with granular contents. The hairs, which are almost invariably
detached in preparing the mount, if not in cleaning the seed, are
often 1.0 mm. long and 0.012 mm. broad in the middle but taper
toward both ends. Invariably the lumen is much broader than
the walls. 2. The Hypoderm Fibers, of which there are several
layers, have thick walls and narrow cavities. They vary in length

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) y b ~.
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Fic. 391. Broom-corn. Transverse section of caryopsis and an empty glume.
Sp, empty glume, consisting of the outer epidermis aep, the fiber layer f,
the spongy parenchyma p, and the inner epidermis iep; g, bundle; sto,
stoma; Fs, pericarp, consisting of the epidermis ep with the cuticle ec, the
hypoderm hy, the starchy mesocarp mes, the cross-cells q, and the tube-cells
sch; N, nucellar or hyaline layer with swollen inner walls s; H, endosperm,
consisting of the aleurone layer al and the starch-cells with starch
granules st and proteid network a. X 160. :

(After Winton, Conn. Agr. Exp. Sta.)
33

514 WEED FLORA OF IOWA

up to 0.5 mm. or more. 3. Spongy Parenchyma. As seen in sur-
face view, the cells of this layer are more or less rectangular with
circular intercellular spaces and resemble those of rice and barley
glumes. 4. Inner Epidermis. In cross section this layer is not
readily studied since the radial walls are usually collapsed; but
in surface preparations, the large elongated cells, often 0.15 mm.
long and 0.05 mm. wide, interspersed with stomata and hairs, are
clearly displayed.

Thin Glume.—Within the lower or first glume and nearly equal-
ing it in length, is the third or thin glume, the remnant of an
abortive flower. This glume is exceedingly thin and membranous
and bears numerous hairs, particularly in the margin. 1. Outer
Epidermis. In general form the cells are similar to those of the
outer epidermis of the thick glumes, but are narrower and much
thinner-walled. The marginal hairs are long (often 0.5 mm.)
single-celled and pointed; but on the surface shorter hairs, with
two or three joints and blunt ends, also occur. Both of these

Fig, 392A Fig. 392B
Fic. 392. Broom-corn. A. aep, outer epidermis and f, fiber of an empty glume
in surface view. X 300.
B. p, spongy parenchyma and iep, inner epidermis of an empty glume in surface
view; sto, stoma; h, hair. X 300.
(After Winton, Conn. Agr. Exp. Sta.)

MICROSCOPIC STRUCTURE OF WEED SEEDS 515

forms have exceedingly thin walls. 2. The Inner Epidermis is dis-
tinguished from the outer by the straight walls and almost entire
absence of hairs.

Flowering Glume.—The fourth or flowering glume, situated be-
tween the upper or second glume and the grain, is also mem-
branous and bears an upwardly barbed awn 5 to 7 mm. long. This
awn, with the larger part of the flowering glume, being readily de-
tached by threshing, it is seldom found in the grain on the market.

Fic. 393. Broom-corn. Glume of rudimentary flower in surface view. aep,
outer epidermis with h, one-celled hair and h, two-celled hair; iep, inner
epidermis. X 300.

(After Winton, Conn. Agr. Exp. Sta.)

Palet—tThis is membranous and hairy like the third or ite
glume, but is much smaller.

Pericarp.—The grain or caryopsis is about 5 mm. long and from
2 to 3 mm. wide, tapering to a blunt point at both ends. It varies
in color from yellow-brown to red-brown.

Harz, Hassack and particularly Mittlacher have described so
fully the histological elements of the caryopsis, that only a brief
description, essential for a clear understanding, need here be given.
1. Eyidermis. The cells are longitudinally extended and have
thick wavy side walls, with more or less distinct pores. Hassack
has noted that the cuticle is of uneven thickness, due to minute
granules or crystals, which may be seen in either section or sur-

516 WEED FLORA OF IOWA

FIG. 394. Broom-corn. Layers of the pericarp in surface view. Significance
of letters same as in Fig. 391. X 160.
(After Winton, Conn. Agr. Exp. Sta.)

face view. 2. The Hypoderm consists of from one to three layers
of cells, with walls somewhat thinner than those of the epidermis.
3. Starchy Mesocarp. Several layers of thin-walled parenchyma
cells, filled usually with small round or rounded polygonal starch
granules seldom over 0.006 mm. in diameter, make up this coat.
In all the varieties here described the starch appears during the
early stages of growth and persists until the fruit nearly or quite -
reaches full maturity. As the caryopsis, even when nearly mature,
is intensely green owing to chlorophyll grains in the outermost
layers of the mesocarp,. it may be inferred that this starch is a
direct product of photosynthesis in the pericarp. So far as I have
observed, the presence or absence of a starchy mesocarp in the
erain at the time of harvest is not a definite varietal peculiarity,
but is dependent on the ripeness of the fruit or other conditions.
Some kernels of the same variety may possess it, while others show
only empty, obliterated cells. Whether or not the starch is present
in a given seed may often be determined by careful scraping and
observation with the naked eye. 4. Cross-Cells. These cells are
usually long and narrow, being distinguished from the tube-cells
only by their transverse arrangement. Near the extremities of
the seed they are, however, shorter and of more irregular shape.
5. Tube-Cells (sch). The cells of this layer lie at right angles to the
_ eross-cells. They are about 0.005 mm. wide and often reach a
length of 0.20 mm. a. Nucellar or Hyaline Layer. This layer is
frequently 0.05 mm. thick. The outer radial walls are thin, but
the inner wall is greatly swollen. In surface view the large cells

MICROSCOPIC STRUCTURE OF WHED SEEDS 517

are conspicuous, not only because of their size, but because of their
yellow or brown color. b. Endosperm. 1. Aleurone Layer (al).
The individual cells of this layer are characterized by their
great variation in size (0.01 to 0.04 mm. in diameter) and form.
2. Starch-Cells (st). In the outer layers the starch granules, if
present, are much smaller than in the interior of the seed, where
they sometimes reach a diameter of 0.083 mm. They are usually
sharply polygonal, with a distinct hilum and radiating fissures.
The starch is surrounded by small protein granules, forming a
network which is especially evident after removing the starch by
reagents. In some specimens, one or more of the outer cell layers
are filled with these protein granules to the complete exclusion of
the starch. )

Sandbur (Cenchrus tribuloides L.).

The pericarp is divided into two portions. The cells of the
outer portion are thick-walled and short; of the inner portion,
elongated, thick-walled and fusiform. The testa consists of one to
two rows of thin-walled cells, much compressed. The aleurone
cells are much larger than in Panicum and Setaria, thick-walled,
densely filled with protein grains. Walls of the starch cells thick-
ened; starch grains larger and loosely arranged.

Timothy (Phlewm pratense L.).

The testa and pericarp are dark colored. The epidermal cells
are thin-walled, elongated, sometimes slightly irregular. The
testa consists of several rows of thick-walled dark brown cells
much longer than broad. The aleurone layer consists of a single
row of cells relatively thin-walled, somewhat variable in size,
solidly packed with aleurone grains. The nucellus is very evident
as a remnant in some places. The cells of this layer are thick-
walled, clear and colorless. The starch cells are much larger than
the aleurone, and contain angular starch grains.

Cheat or Chess (Bromus secalinus L.).

Dr. A. L. Winton describes the microscopic structure as follows:

Flowering Glume.—The structure throughout is much the same
as in darnel, but the cells of the outer epidermis are much more
conspicuously thick-walled, and the wavy-walled cells throughout
much longer than broad. The circular cells also have wavy walls.
The cells on the margins, interspersed with lance-shaped hairs, are
the same as in darnel.

518 WEED FLORA OF IOWA

Fic. 395. Chess (Bromus secalinus). Outer epidermis of flowering glume in
surface view. X 160.
(After Winton, Conn. Agr. Exp. Sta.)

Palet—The flowering glume and palet of chess are very similar
in structure, but the outer epidermis of the latter is barbed on the
keel, the stiff hairs often reaching 45“ in length.

Pericarp (F).—The pericarp consists of two layers with rudi-
ments of another layer in parts. 1. The Epidermal Cells (ep) are
large, elongated-polygonal, and have thin, non-porous walls.
2. Mesocarp. As a rule, the cross-cells immediately underlie the

Fic. 396. Chess. Transverse section of fruit. F, pericarp consisting of
epidermis ep, and cross-cells q; S, testa; N, perisperm; H, endosperm con-
sisting of aleurone layer al, and starch-parenchyma st. X 160.

(After Winton, Conn. Agr. Exp. Sta.)

epidermis, but occasionally traces of the mesocarp are evident.
3. Cross-Cells (q). Whether this layer corresponds with the cross-
cells of the tube-cells of other grasses, I have been unable to decide.

MICROSCOPIC STRUCTURE OF WEED SEEDS 519

The tissue is made up of irregular spongy-parenchyma cells,
usually transversely elongated with large, round or elongated inter-
cellular spaces.

The Testa (S).—Consists of one layer of elongated brown cells
10-20 wide.

Perisperm (N).—This layer is enormously developed. As may be
seen in cross section, the cells are 40“ thick, but the walls are so
swollen as to almost entirely obliterate the cavity. After soaking
for some time in 1 per cent soda solution they are evident in sur-
face view.

Endosperm.—l1. The Alewrone Layer (al) is not of especial in-
terest. 2. The Starch-Parenchyma (st) is remarkable for the thick-
ness of the cell walls (often 10 thick) and the elliptical starch
grains 3-204 in diameter. With proper illumination each grain
may be seen to have an elliptical hilum.

Fic. 397. Chess. Elements of fruit in surface view. Significance of letters same
as in Fig. 396.
(After Winton, Conn. Agr. Exp. Sta.)

Wild Barley or Squirrel-tail Grass (Hordeum jubatum L.).

The grain is adherent to the palet. The epidermis consists of
thick-walled, tangentially elongated ‘cells, most of which are longer
than broad. In part the cells are developed into short conical
trichomes. The underlying cells are thick-walled with prominent
pore canals. The remainder of the adhering palet consists of thin-
walled cells much larger than broad. The pericarp as well as the

520 WEED FLORA OF IOWA

testa is but slightly developed. In some cases the underlying
parenchyma cells are not clearly defined. The blackish pigment is
found in the internal part of the palet; some also occurs in peri-
carps and the aleurone layer. The pericarp consists of one or
two rows of rather thin-walled, tangentially elongated cells. The
testa is reduced to a single layer of cells longer than broad. The
nucellus is nearly absent except in the groove. It consists of a
single row of thin-walled, colorless, compressed cells. In the groove
several rows of cells occur. The aleurone in the specimens studied
is made up of a single row of cells. The cells of the starch layer
are larger than those of the aleurone.

Darnel (Lolium temulentum L.).

Dr. A. L. Winton describes its microscopic structure as follows:

The Flowering Glume is 6-8 mm. long, equaling or exceeding
the caryopsis. It is obscurely five-nerved, lobed at the end, and
bears an upwardly barbed awn often 15 mm. long. Like the glumes
of barley, oats, and other cereals, it consists of four coats, some of
which, however, are lacking on the margins and at the end. 1. The
Outer Epidermis differs greatly in structure in different parts of
the glume. At the margins (as is clearly shown in Fig. 1 by
Moeller*), it consists of straight-walled, elongated cells inter-
spersed here and there with short lance-shaped hairs. On the
ereater part of the surface, however, the cells, as in barley and
some other cereals, are of three kinds: first, cells of wavy outline,

lic. 398. Darnel (Lolium temulentwm). Margin of flowering glume showing
lance-shaped hairs. X 300.
(After Winton, Conn. Agr. Exp. Sta.)

MICROSCOPIC STRUCTURE OF WEED SEEDS 521

into which the straight-walled cells at the margin pass; second,
circular cells corresponding to the conical hair-cell of barley ; third,
exceedingly short, more or less crescent-shaped cells. Near the
‘ margins and on the veins, where they alternate with stomata, the
cells of wavy outline are elongated; but in other parts they are
very short, often being broader than long. Although thick-walled,
the walls are transparent, whereas the middle lamella is con-
spicuous, giving the impression of thin-walled cells. Pores are few
and inconspicuous. Near the margin the circular cells are small
and are usually accompanied by crescent-shaped cells which often
exceed them in size. On the greater part of the glume, however,
the circular cells are much larger, often being 70# in diameter.
Numerous pores are conspicuous, both in the radial and tangential
walls. Often one, sometimes two, crescent-shaped cells accompany
a circular cell. Characteristic of this coat are the short, wavy

Fic. 399. Darnel. Middle portion of flowering glume. X 160.
(After Winton, Conn. Agr. Exp. Sta.)

cells and the numerous circular cells, the latter frequently exceed-
ing in area the former. 2. Hypoderm. The fibers in this layer
are much the same as in cereals. Fibers of similar structure also
make up the ground-tissue of the awn. 3. Spongy-Parenchyma.
The elements are more or less rectangular in shape, like those of
the corresponding layer of barley, and are readily distinguished
from the star-shaped elements of oats. 4. Inner Epidermis. This
layer is made up of thin-walled cells and stomata, and is of no
diagnostic importance.

522 WEED FLORA OF IOWA

Palet.—The two-keeled palet is about the same size as the flower-
ing glume, but is of a thinner texture, owing to the absence of a
well developed hypoderm layer. The Outer Epidermis is much the
same as that of the flowering glume, except that it is barbed on ~
the keels with rigid thornlike hairs 150“ or less in length, as is
shown in Fig. 3 by Moeller.

Fie. 400. Darnel. Keel of palet showing outer epidermis with hair h, and
hypoderm fibers f. X 160.
(After Winton, Conn. Agr. Exp. Sta.)

The Pericarp (F').—Consists of four coats, of which only two, the
epidermis and cross-cells, are fully developed. 1. Epidermis (ep).
Cross sections of the mature seed show that this layer consists of
collapsed, moderately thick-walled cells, which are best studied
after heating with potash. Seen in surface view, the cells at the
apex of the seed are nearly isodiametric, but at other parts are
elongated. The walls are indistinctly beaded. 2. The Mesocarp (m)
is not developed on all parts of the seed, but is conspicuous on the
angles. The cells vary greatly in shape and size, some being ir-
regularly isodiametric, others transversely elongated, resembling the
cells of the next layer. 3. Cross-Cells (q). Especially striking are
the cells of this layer, which resemble the cross-cells of barley. As
has been noted by Moeller, the radial walls appear indistinctly
beaded, but this is evident only under favorable conditions.
4. Tube-Cells, spongy-parenchyma, and various intermediate forms,
make up the interrupted inner layer of the pericarp.

Testa (S).—The cells are for the most part elongated and are
often diagonally arranged with reference to the axis of the fruit. In

MICROSCOPIC STRUCTURE OF WEED SEEDS 523

42m” 4

Fic. 401. Darnel. Transverse section of fruit. F, pericarp consisting of
epidermis ep, mesocarp m, cross-cells q, and tube-cells sch; S, testa con-
sisting of outer layer a. and inner layer i; N, perisperm; f, fungus layer;
HE, endosperm consisting of aleurone layer al, and starch-parenchyma st.
x 160.

(After Winton, Conn, Agr. Exp. Sta.)

transverse sections this coat often separates from the pericarp on
the one hand and the perisperm on the other. Examined in water,
only one cell layer (the inner) is evident; but successive treat-
ments with 5 per cent potash, dilute acetic acid and chlorzine
iodine, bring out two layers. 1. The Outer Layer (a) is made up
of thin-walled cells with cuticularized outer walls. Treated as
above described, the cuticle is colored yellow-brown, the radial and
inner walls, blue. 2. The Inner Layer (1) is not only thicker than
the outer, but the cells are thicker-walled and, in addition, swell
greatly with potash. These swollen walls are stained deep blue by
chlorzine iodine, thus differentiating them from the yellow-brown
cuticle on the inner wall.

Perisperm (N).—Characteristic of this seed is the nucellar-coat,
consisting usually of two cell layers. In cross section these cells
are rectangular with swollen walls; in surface view, as maybe
seen after soaking for a long time in dilute potash, they are:ir-
regularly polygonal or more or less elongated. Shines

Fungus Layer (F').—In most specimens a layer of fungus-threads
20 thick is present between the perisperm and the aleurone layer.
So commonly is this fungus present in darnel grown in Europe,
that it is of no little value in identifying the grain; but it remains
to be determined whether in California, where the plant is a pest

524 WEED FLORA OF IOWA

in wheat fields, the fungus is also a common accompaniment. After
treatment with potash this layer is stained bright yellow by zine
chloride of iodine.

Endosperm.—1. The Aleurone Cells (al) vary from less than 20
to 40“ in diameter. 2. Starch-Parenchyma (st). The thin-walled
cells contain small polygonal grains 3 to 7# in diameter. The in-
dividual starch grains are not distinguishable from the grains of
rice and oats, and like the latter, often occur in aggregates of
various sizes.

:

Nez

Ps ne :

Fic. 402. Darnel. Elements of fruit in surface view. Significance of letters
same as in Fig. 401. X 160.
(After Winton, Conn. Agr. Exp. Sta.)

URTICACEAE, NETTLE FAMILY.
Hemp (Cannabis sativa L.).

The smooth crustaceous achene consists of an outer epidermal
layer of thick-walled cells with wavy outline, the thickness of the
radial walls varying somewhat. This is followed by a layer of
loosely arranged parenchyma cells, and a layer of cells with brown
contents. A layer of small cells spoken of as the dwarf cells by
Winton, may also be made out in some sections. The palisade
layer consists of thick-walled cells with pore canals, the walls
having a wavy outline. The cell cavity is very much reduced.
The testa is very thin and consists of thin-walled elongated paren-
chyma cells, the second layer of spongy parenchyma. The com-

MICROSCOPIC STRUCTURE OF WEED SEEDS 525

pressed nucellus follows. The endosperm consists mostly of a
single layer of cells, the embryo of small epidermal cells and the
elongated palisade parenchyma on the upper face of the cotyledon;
cells of embryo and endosperm contain fat and protein.

Nettle (Urtica gracilis Ait.).

The pericarp of the small achenes consists of an outer epidermal
layer of rather large cells with exterior walls thickened, and
underneath several layers of loosely arranged parenchyma cells.
The testa and nucellus are compressed; cells of the embryo squarish,
containing fat and protein grains.

Fic. 403. Microscopic structure of the seeds of the Nettle family. (Urticaceae).
I. Hemp (Cannabis sativa). II. Common nettle (Urtica gracilis).
ep=epidermis, thick-walled short cells, underneath followed by a pigment layer,
thinner-walled parenchyma cells and a layer of thick-walled cells. pal=
palisade cells. p=parenchyma cells with the pigment. t=testa. n=

nucellus. em=embryo.
(Drawings by L. H. Pammel and Charlotte M. King.)

POLYGONACEAH,* BUCKWHEAT FAMILY.

Miss E. Sirrine finds, ‘‘In the seed coats of the family, the
palisade portion constitutes the outer part of the achenium; this is
followed in most cases by the testa consisting of several layers of
eells varying, however, in some cases; they are quite regular in
form and in some instances are of a dark color. In the mature
palisade cell, the cavity is present; this varies greatly in the dif-
ferent genera; in some cases occupying nearly the entire cell, in
others small and irregular.’’

*A study of the microscopic structure of the achenes is largely based on Miss
Emma Sirrine’s work and upon that of Dr. Winton.

526 WEED FLORA OF IOWA
Sorrel or Sour Clover (Rumesx acetosa L.).

This species has very small palisade cells, rectangular in shape
and with a small cell cavity which occupies only a small portion
of the lower end of the palisade cell. No canals or irregularities
of cell cavity.. The cell is light in color while canal is darker.
The sub-palisade portion is composed of small round cells of a
variable number. The endosperm is composed of irregularly ar-
ranged cells. Measurements: whole seed coats, 38.34; palisade
cells, 23"; sub-palisade, 13.2.

<n
7

Fic. 404. Microscopic structure of the seed of some Polygonaceous weeds.
I. Buckwheat (Fagopyrum esculentum). II. Curled Dock (Rumez crispus).
III. (Wild Buckwheat or Bindweed (Polygonum convolvulus). IV. Smart-
weed (Polygonum persicaria). WV. Sorrel (Rumex acetosa). VI. Knotweed
(Polygonum erectum). VII. Smartweed (Polygonum hydropiper).
e=epidermis. sd=sclerotic layer. t=testa. al=aleurone layer. p=parenchyma
cells,
(Drawings by L. H. Pammel.)

MICROSCOPIC STRUCTURE OF WEED SEEDS 527

Curled Dock (Rumex crispus L.).

The brownish achenes of this species consist of an epidermal
layer of elongated cells with thick stratified walls, outer wall
colorless and a thick cuticle. The underlying parenchyma cells
of three rows are smaller, with thick, brownish walls; cells contain
tannin. The testa consists of two layers of cells, one large, thin-
walled with brownish walls, the other compressed. The endosperm
cells are large, thin-walled, and contain simple starch grains.

Lady’s Thumb or Smartweed (Polygonum persicaria L.).

In this species the palisade cells are long, narrow and truncate.
The cell cavity extends the whole length of cell at the upper end,
with prominent branching pore canals. The sub-palisade portion
consists of four layers of small roundish cells, a small chainlike
layer also between the sub-palisade and endosperm. The endosperm
consists of large irregular cells. Measurements: 138.64; palisade
cells, 108.9%; sub-palisade, 29.7+.

Knotweed (Polygonum erectum L.).

In this species the ‘‘palisade cells’? are much broader than in
the other species here described. The cells have irregular papillate
projections as in P. dumetorum var. scandens. The cell cavity is
narrow with long canals extending from it; cavity branches divide
near the end of the cell. In P. erectum the whole cell is of a light
brown color while the cavity is colorless. The sub-palisade portion
consists of two layers of isodiametric cells. The endosperm has
long, narrow, regular cells. Measurements: whole seed coat, 82.54;
palisade cell, 60“; sub-palisade, 22.54; papillate projections, 3.3+.

Smartweed (Polygonum hydropiper L.).

In this species the palisade cells are long and narrow, very
irregular and truncate at end. The cell cavity is very narrow
and extends nearly the whole length of the cell. The cavity has
sinuate canals which extend out from sides of the cavity. The cell
is colored light brown while the cavity is deeper in color. The
palisade cells resemble very much those of P. virginianum. The
sub-palisade cells, however, are much smaller with more numerous
indistinct layers, there being at least six layers well defined. The
endosperm cells also are small and quite irregular. Measurements:
whole seed coat, 132; palisade cells, 92.4; sub-palisade, 39.6.

528 WEED FLORA OF IOWA

Wild Buckwheat or Bindweed (Polygonum convolvulus L.).

Dr. A. L. Winton describes its microscopic structure as follows:

Pericarp (f£).—The black hulls or shells of the grain should be
studied in cross section and in surface preparations, the latter
being freed from the black coloring matter by warming on the slide
with caustic alkali, or better by boiling for half an hour with
1.25% sodium hydrate solution as in the determination of crude
fiber. 1. Eptcarp (epi). Cross sections show that the cells are
about 0.10 mm. in radial diameter on the sides of the achenes and
are still longer at the angles. The inner wall is thin, but the outer

Fic. 405. Black Bindweed. (Polygonum convolwulus): Transverse section of the
fruit. C, calyx; Epi, epicarp; Mes. mesocarp; B, fibro-vascular bundle; S,
testa; H, endosperm; Hm, embryo. X 16.

(After Winton, Conn. Agr. Exp. Sta.)

wall and the outer portions of the curiously wrinkled radial walls
are strongly thickened. Proceeding from the inner wall outward,
the radial walls increase in thickness until the much-branched eell
cavity is almost obliterated. On the surface are numerous warts
from 0.015 to 0.03 mm. in diameter, into each of which a narrow
branch of the cell cavity passes. Surface preparations of the
pericarp with the outer surface uppermost clearly show that the
warts are arranged in irregular longitudinal rows, also that the
epicarp cells at the surface are sinuous in outline, but gradually
approach a circular form farther inward. As may be seen in
preparations of the pericarp with the inner surface uppermost,
the contour of the inner cell walls of the epicarp is, like the
outer wall, sinuous in outline. 2. Hypoderm (hy). Beneath the
epicarp is a layer of slightly elongated parenchyma cells somewhat
larger than the cells of the mesocarp. 3. Mesocarp (p.) At the
angles of the fruit this layer is somewhat thicker than on the
sides. The cells of the ground tissue are thin-walled and
isodiametric, those of the inner layers being more or less obliterated

MICROSCOPIC STRUCTURE OF WEED SEEDS 529

“7 7

\
\
\ \

hy p end ae q ie al

Fic. 406. Black Bindweed. Transverse section of the fruit. C, calyx consist-
ing of the outer epidermis aep, the mesophyll m and the inner epidermis
iep; F, pericarp consisting of the epicarp ei with cuticular warts w, the
mesocarp p and the endocarp end; S, testa consisting of the outer
epidermis ae, the cross-cells q and the inner epidermis ie; H, endosperm
consisting of the aleurone-cells al and the starch-cells s. X 160.

(After Winton, Conn. Agr. Exp. Sta.)

in the ripe fruit. Six primary, sparingly branched vascular
bundles pass longitudinally through the ground tissue of the
mesocarp, one in each angle and one in each of the faces.
4. Endocarp (end). like the inner mesocarp, the cells are usu-
ally obliterated in the mature seed and are seldom evident either
in cross section or in surface view.

Testa (S).—Three coats, analogous to those of buckwheat, but
differing in form, make up the testa. 1. Hpidermis (ae). As in
buckwheat, the epidermal cells are wavy in outline; but in bind-
weed they are strongly elongated, whereas in buckwheat they are

nearly isodiametric. 2. Cross-Cells (q). Most of the cells of
34

630 WEED FLORA OF IOWA

this layer are elongated, resembling the tube-cells of cereals; but
short cells of more irregular shape also occur, particularly near
the base and apex. These are more or less separated from each
other, but in no part do they form a spongy parenchyma with
circular intercellular spaces like that of buckwheat. 3. Inner
Epidernis (ie). This coat consists of thin-walled, elongated ele-
ments.

Fig. 407A Fig. 407B

Fic. 407. Black Bindweed. A. Epicarp in surface view. X 160.
B. Tangential section of the epicarp.
(After Winton, Conn. Agr. Exp. Sta.)

Endosperm (E).—None of the elements are distinguishable from
those of buckwheat, either in form or size. 1. Aleurone Cells (al)
are of variable size and irregular shape. 2. Starch-Cells (s). In
the outer layers the cells are tangentially elongated; farther in-
ward, they are radially elongated and of large size. The polygonal
or rounded granules vary in diameter from 0.003 to 0.012 mm.
Vogl has noted that after treating the starch aggregates of buck-
wheat with caustic potash, there remains. a network corresponding
to the outline of the starch granules, the threads of which are of
homogeneous structure without granules. This phenomenon I have
also observed in the fruits of P. convolvulus and other species of
Polygonum as well as in a number of species of Rumezx, and it is
probably characteristic of the entire family. The Embryo, con-
sisting of an elongated radicle and two oblong cotyledons, may be
conveniently isolated by soaking the seed in 1.25 per cent. caustic
soda solution for some hours until the starch is removed.

MICROSCOPIC STRUCTURE OF WEED SEEDS 531

( <>
HULL ee rt
mat OE
=| unum: UNE

} TUM
pee

twin mM mn

Fic. 408. Black Bindweed. Seed in surface view. Significance of letters same
as in Fig. 406.
(After Winton, Conn. Agr. Exp. Sta.)

Detection in Powder Form.—Characteristic of this fruit are
the papillae on the outer epidermis of the calyx and the epicarp
with sinuous cell walls and rows of warts. The outer epidermal
cells of the testa are sinuous in outline, like those of buckwheat,
but, unlike the latter, are commonly elongated. Although the cross-
cells are morphologically the same as the spongy parenchyma of
buckwheat, they resemble more nearly in structure the tube-cells
of the cereals.. The starch granules are not characteristic and the
network obtained after treatment with caustic alkali serves merely
as an indication that the seed belongs to a Polygonaceous plant.

Buckwheat (Fagopyrum esculentum Moench.).

The achenium consists of elongated epidermal cells with thick-
ened walls, underneath similarly elongated thick-walled sclerotic
parenchyma cells with pore canals. This layer contains the pig-
ment. The testa follows the pericarp and is differentiated into
an epidermal layer of yellowish brown walls, followed by smaller
thin-walled, parenchyma cells. The testa is much compressed; the
albumen consists of an outer aleurone layer of small cells followed
by larger cells. The albumen cells contain compound starch
grains.

532 WEED FLORA OF IOWA

4)
b)

Fic. 409. Black Bindweed. Surface view of the pericarp from below. X 160.
Significance of letters same as in Fig. 406.
(After Winton, Conn. Agr. Exp. Sta.)

CHENOPODIACHAH, GOOSEFOOT FAMILY.
Goosefoot or Lamb’s Quarters (Chenopodium album L.).

Harz has given an account of the structure of Beta and Spinacia.
The structure of the seed of lamb’s quarters is somewhat different.
The thin utricle consists of an epidermal layer of somewhat wavy
eells and an indistinct layer underneath. The testa contains the
brownish pigment. The cells are thick-walled; the nucellus is com-
pressed. The cells of the endosperm are large and contain an
abundance of small starch grains.

Russian Thistle (Salsola kali (.) var. tenutfolia G. W. F. Meyer).

The seed is without endosperm; the embryo fills the seed, and
is coiled in a conical spiral. The seed coat consists of two parts,
a layer of three rows of elongated cells followed by a layer of
three rows of irregular parenchyma cells. One side of the seed
coat is wider than the other and these cells contain an abundance
of calcium oxalate crystals. The cells of the outer layer of the

MICROSCOPIC STRUCTURE OF WHEHD SEEDS 533

embryo are somewhat elongated; the remainder are nearly as broad
as long; these contain no starch but albuminoids and fat.

Fic. 410. Microscopic structure of seeds of the Chenopod family. (Chenopodia-
ceae). I. Russian Thistle (Salsola kali var. tenwifolia). II. Lamb’s Quar-
ters (Chenopodium album). us

ep=epidermis. p=parenchyma cells. t=testa. n=nucellus. en=endosperm.

(Drawings by L. H. Pammel and Charlotte M. King.)

NYCTAGINACEAE, FOUR-O’CLOCK FAMILY.

Wild Four-o’clock or Umbrella Plant (Oxybaphus nyctagineus
(Mx.) Sweet).

The nutlike fruit of the wild four-o’clock or umbrella plant is
somewhat hairy; the outer portion of the pericarp is made up of
thick black-brownish cells from 6 to 9 rows. The epidermal cells
are smaller, some of the cells elongated into one-celled thick-walled
trichomes. Adjacent to the testa are bundles of thick-walled,
sclerotic cells, the outer layer of cells of the testa consisting of
mucilaginous cells with colorless walls. This is followed by a
second layer of thin-walled parenchyma cells. The nucellus con-
sists of an indefinite granular mass, followed by the endosperm,
and the thin-walled cells of the embryo. |

CARYOPHYLLACHAH, PINK FAMILY.
Soapwort or Bouncing Bet (Saponaria officinalis L.).

The kidney-shaped, black, roughish seeds consist of tangentially
elongated, thick, black, rough cells, the outer layer being brownish
colored, while the cell cavity is red or blackish brown. . The inner
walls of the testa are thinner, the cells are elongated and the inner
seed coat is much compressed. The nucellus is indistinguishable
from the inner seed coat. This is followed by the endosperm,

534 WEED FLORA OF IOWA

Fig. 411. Wild Four-o’clock (Oxybaphus nyctagineus). The sclerotic paren-
chyma, parenchyma and epidermis belong to the pericarp.
ep=epidermis. p=parenchyma. scl=sclerotic parenchyma. t=testa. t=tri-
chome. en=endosperm. r=ribs.

(Drawing by L. H. Pammel and Charlotte M. King.)

consisting of an outer tangential layer with granular contents.
The aleurone layer and remaining portion of the endosperm cells
consist of large rather thin-walled cells with compound starch
grains and protein.

Slender Catchfly (Silene antirrhina L.).

The small kidney-shaped seeds are rough and brownish in color.
The outer epidermal walls are thick, brownish black in color. The
underlying parenchyma cells are tangentially elongated with near-
ly colorless walls, This is followed by an indefinite layer con-

MICROSCOPIC STRUCTURE OF WEED SEEDS 535

sisting of an inner seed coat and a nucellus. The endosperm con-
sists of thin-walled parenchyma cells with granular contents con-
sisting of starch grains and protein.

Zi

Fic. 412. Microscopic structure of some seeds of the Pink family (Cary-
ophyllaceae).
I. Bouncing Bet (Saponaria officinalis). II. Catchfly (Silene antirrhina). III.
Virginia Catchfly (Silene virginica).
ep=epidermis. p=parenchyma. n=nucellus. h=hypoderm cells. en=endo-
sperm.
(Drawings by L. H. Pammel.)

The seeds of Virginia Catchfly (Silene virginica) are irregular.
The outer walls are greatly thickened, irregular, the underlying
parenchyma cells being slightly elongated. This layer is followed
by the nucellus and the aleurone layer and remaining endosperm
cells containing starch grains and protein material.

Silene inflata is described and figured by Harz*.
*Samenkunde 2 :10-79.

536 WEED FLORA OF IOWA
RANUNCULACEAE, CROWFOOT FAMILY.
Common Buttercup (Ranunculus abortivus L.).

The greenish achenes of the buttercup consist of three distinct
layers. The outer epidermal is of elongated, thickish black cells.
The cells containing the brown pigment are yellowish brown.
The underlying layers of three or four rows of seeds are similar
but larger and paler in color. This layer is followed by a thick-
walled sclerotic layer containing three or four layers of thick-
walled cells with pore canals. The testa consists of an outer layer
of thin-walled parenchyma cells; the inner layer consisting of
sclerotic parenchyma cells filled with pore canals. The endosperm
cells are large or thin-walled and contain protein material. Harz
has given an account of the structure of R. arvensis*.

ic. 413. Microscopic structure of the seed of Buttercup (Ranunculus aborti-
VUS).
ep=epidermis. p=parenchyma. scl=sclerotic parenchyma. en=endosperm.
(Drawing by L. H. Pammel and Charlotte M. King.)

PAPAVERACEAE, POPPY FAMILY.
Common Poppy (Papaver somniferum L.).

Prof. A. L. Winton describes the seeds of this plant as follows:
Testa (S).—Cross sections are prepared after soaking the seed
in water that may be cleared with chloral or alkali. After soaking
the whole seed for about twenty-four hours in 1 per cent sodium
hydrate solution, the first four layers readily separate from the

*Landw. Samekunde 2 :10-64.

MICROSCOPIC STRUCTURE OF WEED SEEDS 537

fifth. Subsequent treatment with hydrochloric acid dissolves out
the calcium oxalate, and staining with chlorzine iodine or safranin
renders the outer layers more distinct. 1. The Hpidermal Cells
(ep) are polygonal and of enormous size, corresponding to the net-
work on the seed. As appears in cross section, the cells are col-
lapsed except in the neighborhood of the radial walls. In surface
view the radial walls are sinuous and thin, what are often con-
sidered the thick dark walls of this layer being not the walls at all,
but the ribs formed by the thickening of the second and third
layers. This conclusion is consistent with Meyer’s and Hanausek’s
figures of cross sections, also with Meyer’s drawings and Mach’s
photomicrographs of surface preparations. The statement of
Tschirch and Oesterle that the epidermis consists of elongated cells
situated over the ribs, with large polygonal cells between, has since
been corrected by the authors themselves. Doubtless they mistook
some of the cells of the second layer for epidermis. Hanausek’s
surface view, on the other hand, might convey the impression that
the ribs were the cell walls, but his description and cross section
clearly show their true nature. 2. Crystal Layer (k). On the

Fic. 414. Poppy Seed (Papaver somniferum). Transverse section. s, testa
consisting of epidermis ep, crystal layer k, fiber layer f, cross-cells q and
netted-cells n; e, endosperm containing aleurone grains al. X 160.

(After Winton, Conn. Agr. Exp. Sta.)

ribs, the cells of this layer are more or less tangentially elongated,
but between the ribs are isodiametric and polygonal, the elongated
cells having longer radial walls than the others, thus contributing
to the formation of the ribs. They contain fine, granular crystals
‘of calcium oxalate. Meyer has demonstrated that the blue color
of the poppy seed is due, not to a blue pigment, but to the inter-
ference of light by the crystals over the brown cells in the back-
ground, and is the same phenomenon that causes the apparent
blue color of the sky and the iris of the eye. As soon as these
erystals are dissolved in hydrochloric acid, the seed appears brown.

538 WEED FLORA OF IOWA

3. Fiber Layer (£). The fibers of this layer are 15-40" broad
and are parallel to the curved axis of the seed. Seen in cross
section, this layer is thickest in the ribs, the walls throughout
being distinctly thickened and stratified. In surface view they
are rendered more distinct by chlorzine iodine. 4. Cross-Cells (q).
The fourth layer consists of moderately thick-walled, transversely
elongated, pointed cells arranged side by side in rows. The walls
_ are impregnated with brown material. 5. Netted-Cells (n). Ow-
ing to the netted-veined, colorless walls and the presence of deep
brown contents, these cells are particularly striking. They are
arranged transversely and often side by side in rows. The cell
contents are insoluble in alkali and do not give the tannin re-
action. Some authors designate the cells of this layer ‘‘Pigment
cells,’ notwithstanding the fact that in the white poppy they do
not contain pigment. Meyer, Tschirch and Oesterle, Vogl, and
Hanausek describe an inner layer of thin-walled cells, but I am
unable to find such a layer except in the vicinity of the hilum.

Fic. 415. Poppy seed. Testa in surface view. Significance of letters same as
in Fig 414. pig, pigment. X 160.
(After Winton, Conn. Agr. Exp. Sta.)

The Endosperm (E) contains aleurone grains up to 34 in
the outer layers and 7 in the inner layers, each grain containing
several globoids and crystaloids.

Embryo.—In the cotyledons there is only one layer of palisade-
cells and these cells are only slightly elongated. The aleurone
grains are like those of the endosperm.

MICROSCOPIC STRUCTURE OF WEED SHEDS 539

Prickly Poppy (Argemone intermedia Sweet).

The blackish pitted seeds are difficult to study. They consist
of nearly colorless epidermal cells, with thick outer walls and
cuticle. The cells of the underlying layer are thick-walled, walls
and contents blackish, difficult to make out on account of dense

Fic. 416. Rocky Mountain Poppy (Argemone intermedia).
ep=epidermis with thick outer walls. pi=pigment layer, n=nucellus, en=en-
dosperm. :
(Drawing by L. H. Pammel and Charlotte M. King.)

pigment. The nucellus is compressed, colorless. The endosperm
of large cells contains oil in large amounts, and protein. The
structure seems to differ in a marked degree from Papaver as
described by Harz and G. Kraus..

CRUCIFERAH, MUSTARD FAMILY.
Virginia Peppergrass (Lepidium virginicum L.).

The seed coats consist of three well defined layers. The outer
or epidermal cells are tabulated, somewhat compressed. The cuticle
forms a continuous layer over these. On the addition of water the
epidermal cells elongate and form a mucilaginous mass, showing
stratified layers. These are not difficult to make out when the
specimen is mounted in water. The cell cavity is very much re-
duced; that portion of the cell wall in contact with the cell cavity
is differentiated from the outer cell wall substance. Long con-
tinued addition of water causes the cuticle to break and the exterior
becomes very irregular.

The second layer is colored brown, the cell walls are considerably
thickened laterally and project upwardly in the shape of cones.
A section made through the ends of these seeds shows that the
second layer is considerably more developed and there are evidences

540 WEED FLORA OF IOWA

here of an indistinct layer between the first and second. The
layer following this consists of thin-walled parenchyma cells, in
some cases considerably elongated but in others short.

The third layer is followed by the endosperm which consists of
a layer of rather thick-walled parenchyma cells. These carry
granular protein grains. This is followed by one or more layers
of elongated cells, in which the cell cavity is very much reduced.
These cells reach their highest development between the folds of
the caulicle and cotyledon.

The cells of the first layer of the embryo are smaller, quite uni-
form in size and filled with protein grains and oil.

Small Peppergrass (Lepidium apetalum Willd.).

The cuticle forms a continuous layer over the epidermal cells,
which are larger than in LD. virginicwm. On the addition of water
the cell wall rapidly elongates, emitting a copious mucilage. The
cell cavity is very much reduced but longer than in L. vwirginicum.
It is surrounded by a denser, more or less differentiated part of
the cell wall which is more yellow in color than the remainder of
the cell wall. The second layer is of a yellow straw color and
consists of very minute cells with small cell cavities.

The cell walls of the third layer are strongly thickened, brown,
and serve the same purpose as in the other species. The endosperm
consists of thick-walled parenchyma cells.

In the first layer of cells, the cell walls are very much larger
and packed with protein grains. The other layers of endosperm
consist of smal] elongated thick-walled cells with a small cell cavity.
These attain their greatest development between the caulicle and
cotyledon. In the embryo, the cells of the first row are isodiametric
filled with protein grains and oil. The outer cells are elongated
larger, and also densely packed with the same material.

Shepherd’s Purse (Capsella bursa-pastoris (L.) Medic.).

The seed coats attain their maximum development in the region
of the caulicle. Cuticle covers the epidermal cells, the latter
tabular, compressed but in the addition of water elongating, be-
coming mucilaginous and showing stratification.

The second and third layers are brown with thick cell walls.
Fourth layer consists of endosperm, one layer of isodiametric cells
filled with protein grains, followed by thick-walled cells reaching

MICROSCOPIC STRUCTURE OF WHED SEEDS 541

Fic. 417. Microscopic structure of seeds of Mustard family (Cruciferae).
I. Hedge Mustard (Sisymbriwm canescens). II. Small Peppergrass (Lepidium
apetalum). To the right an enlarged epidermal cell with mucilaginous walls.

ep=epidermis. p=parenchyma. em embryo.
(Drawing by L. H. Pammel.)

their greatest development between the cotyledon and caulicle.
First row of cells of embryo. nearly isodiametric, filled with oil
and protein grains. Others somewhat larger contain the same
substances. Cotyledons incumbent. Central part of caulicle sepa-
rated from the rest. Cells of caulicle very much larger than cells
of cotyledons.

Black Mustard (Brassica nigra Koch.).

The cuticle covers the epidermal cells as a continuous layer;
when mounted in alcohol the outer layer is very much compressed
and shows very slight stratification; the cell walls expand and
after it has been moist for a considerable time the cuticle breaks.
Stratification is very evident on the addition of water. The second
layer consists of rather thin-walled parenchyma. The cells of

542 WEED FLORA OF IOWA

Fic. 418. Microscopic structure of some Cruciferous seeds (Cruciferae).

I. False Flax (Cameélina sativa). II. Black Mustard (Brassica nigra). III.
Common Mustard (B. arvense). IV. Winter Cress (Barbarea vulgaris).
V. jPeppergrass (Lepidium virginicum). VI. Tumbling Mustard (Sisym-
brium altissimum). VII. Shepherd’s Purse (Capsella bursa-pastoris).

t=testa. p=parenchyma cells. n=nucellus. em=embryo.

I, II, III, and IV. Hlongated palisade cells below the epidermal layer and
parenchyma cells. To the right of I, epidermal cells after the addition
of water.

(Drawings by L. H. Pammel.)

this layer differ greatly with reference to their size, being scarcely
at all developed in places, in others nearly as large as the cells
of the outer layer.

MICROSCOPIC STRUCTURE OF WEED SEEDS 543

The third layer consists of thick-walled parenchyma cells, densely
packed, radially elongated, sides presenting a cone-shaped appear-
ance. Underneath this is a layer of thick-walled parenchyma cells
which contain some coloring matter. The endosperm follows this
layer. The first layer consists of thick-walled cells, densely packed
with albuminous matter. The remaining cells vary in number,
are much elongated, thick-walled with a small cavity; these cells
extend down between the contiguous portions of the cotyledon or
caulicle.

The Embryo—tThe cells of the first layer surrounding the
cotyledon or caulicle are smaller, filled with fat and protein grains.
The remaining cells are larger, also filled with fat and protein
grains. The central part of the caulicle shows a differentiation of
the embryonic vascular portion, consisting of small cells.

Charlock or Common Mustard (Brassica arvensis (L.) Ktze.).

The outer layer of cells is compressed, tabular, with stratification
not evident, and cuticle well developed, and forms a continuous
layer over the outer cells; on the addition of water, the cell walls
become mucilaginous, elongate, stratification becomes evident, the
cuticle breaks, and an irregular surface is formed. The second
layer is but slightly developed, made up of thin-walled parenchyma
cells. The cells of the third layer are elongated and thickened
laterally. These cells are much longer than in B. nigra and brown
in color. The fourth layer consists of one to two rows of rather
thin-walled cells carrying pigment. Endosperm consists of several
rows of cells; first row nearly isodiametric, filled with protein
erains. The three or four layers of cells following are thick-walled
with a small cell cavity.

Embryo.—First layer of cells nearly isodiametric, those follow-
ing somewhat larger, filled with protein and fat grains.

Fiedge Mustard (Sisymbrium. officinale Scop.).

Cuticle covering the epidermal cells, the latter tabular, much
compressed. On the addition of water the cell walls become
mucilaginous with evident stratification. The cells of the second
layer are brown and thin-walled, much compressed. On addition
of choloral hydrate they expand. Third layer much darker than
the second, thick-walled, followed by endosperm, cells elongated,
filled with protein grains, followed by elongated thick-walled cells

544 WEED FLORA OF IOWA

with a small cavity. These reach their highest development between
cotyledons and caulicle. First row of cells of the embryo nearly
isodiametric, filled with protein grains and oil.

Tumbling Mustard (Stsymbrium altissimum L.).

On the addition of water the cell wall of the outer seed coat
becomes mucilaginous. Outer epidermal layer covered with cuticle,
cells elongated, on the addition of water, walls become mucilaginous
and show stratification. Cell walls of second layer thick, light
brown, followed by endosperm of two layers of cells, first elongated,
thick-walled. Cells of embryo as in S. officinale.

Hairy Hedge Mustard (Sisymbriwm canescens Nutt.).

The testa of the small brownish cells consists of an outer
epidermal layer with thick walls. These cell walls become mucil-
aginous on the addition of water. This is followed by a layer of
several rows of brownish cells and a compressed layer, the nucellus.
The cells of the outer row of the embryo are smaller than the
underlying cells.

Common Winter Cress or Yellow Rocket (Barbarea vulgaris R. Br.).

First layer of outer seed coat not well developed, cells elongated
in the direction of the seed. Cuticle covers the epidermal cells.
On the addition of water a slight mucilaginous modification takes
place. Second layer with thick lateral walls and quite large cell
cavities, colored brown. Third layer of rather thick-walled
parenchyma cells also colored brown, followed by endosperm as is
usual in cruciferous seeds.

False Flax (Camelina sativa (Li.) Crantz.).

Seed coats consisting of four layers. The outer epidermal cells
not much longer than wide, on the addition of water become
mucilaginous and well stratified. On the addition of chloral hydrate
stratification is more evident. The cell walls are differentiated
into several layers. The second layer is not always developed.
Cells of third layer with thick walls and brown pigment, followed
by a narrow layer of thick-walled brown cells. The first row of
cells of endosperm, rather thick-walled, filled with protein grains,
the other layers of unequal development, cells elongated, thick-
walled; followed by cells of embryo; these contain protein grains
and fat.

MICROSCOPIC STRUCTURE OF WEED SEEDS 545
ROSACHAH, ROSH FAMILY.
White Avens (Geum canadense Jacq.).

A greater part of the so-called seed is made up of the pericarp
consisting of a layer of small epidermal cells with trichomes. The
underlying parenchyma cells are large with numerous intercellular
spaces. -The testa is thin, consisting of an outer pigment layer
followed by several rows of thick-walled, colorless cells.

Fic. 419. Microscopic structure of fruit of Avens (Geum canadense).
ep=epidermis. p=parenchyma. per=pericarp. t=trichome. t'!=testa.
(Drawing by L. H. Pammel and Charlotte M. King.)

LEGUMINOSAE,* PULSE FAMILY.
Rattlebox (Crotalaria sagittalts L.).

The testa not strongly developed; endosperm 196” in thickness.
From Nadelmann’s studies it appears that in Crotalaria verrucosa
the horny endosperm is well developed, being four and one-half
times as wide as the testa. The aleurone layer contains fat. and
aleurone grains. The cells of the embryo contain protein and fat
but no starch.

*The descriptions here given are taken for the most part from a paper by
L. H. Pammel, Trans. Acad. Sci. St. Louis, 9.

30

546 WEED FLORA OF IOWA

Malpighian.—The cells are prismatic in surface view, 9.84
across, with five to six canals. In cross sections they are 84# long.
The cuticle forms a continuous layer, with longitudinal canals pro-
jecting into the cells; these extend down through the upper part
of the cell wall and the cuticularized substance; this layer is lighter
in color than the rest of the cell wall, and separates from the re-
mainder of the cell in the form of a band. The narrow light line
occurs close under the cuticularized layer. The cell cavity is
narrow and gradually tapers upward; it contains some protein
matter. The cell wall consists of cellulose.

Osteosclerid.—The walls are thickened. Cells wide in the lower
part and narrowing upwards, with large intercellular spaces. Cells
contain protein.

Nutrient— Consists of radially elongated cells, which are slightly
compressed. Walls of medium ‘thickness, shghtly colored.

Fic. 420. Microscopic structure of the testa of Rattle-box (Crotalaria sagittalis).
ll=light line. m=malpighian cells. n=nutrient layer. o=osteosclerid.
(Drawing by L. H. Pammel.)

‘Endosperm—Not strongly developed. The cells of the aleurone
layer large, containing protein. Two layers follow this, the cells
very much compressed, and somewhat radially elongated, of thick-
walled cells. All of the cells contain protein and fat.

Embryo.—Cells of outer row smaller; those adjoining the en-
dosperm thicker walled, the inner part with thinner walls. The re-
maining cells of the embryo larger. All of the cells filled with
protein. Starch is absent.

Black Medick (Medicago lupulina L.).

Testa and endosperm well developed, 245“ in thickness on sides.
More than half of this thickness consists of endosperm.

MICROSCOPIC STRUCTURE OF WEED SEEDS 547

Malpighian.—Cells 40-424 in length. Cuticle slightly irregular;
underneath the cuticle a light colored area with conical projec-
tions, as in Melilotus, but somewhat more prominent. With chlor-
iodide of zine this rapidly colors blue. It corresponds to the
mucilaginous ‘‘membrana interna’’ of Mattirolo and Buscalioni,
and, as shown by Schips, is chemically differentiated from the
cuticle and remainder of the cell wall. The conical layer is highly
refractive. The light line occurs below the conical layer and colors
blue soon after the addition of chlor-iodide of zine. The cell cavity
is broadest at the base, gradually tapering upward. A large
chromatophore occurs at the base or near the middle of the cell
cavity. In colored seed some pigment occurs in the cavity as well
as considerable amounts in the walls. Small pore-canals occur in
the upper part of the cell wall. The cell walls color blue more
slowly with chlor-iodide of zine than the cuticularized layer.

Osteosclerid—Cells broad at the base, with conspicuous longi-
tudinal pores; intercellular spaces below the Malpighian cells tri-
angular; walls colored brownish; cells containing pigment and
tannin. ri ;

Nutrient.—This layer is much compressed, and differentiated
into two parts; cells elongated, rather thin-walled; those in the
lower portion carry a great deal of pigment, and are much more
compressed than the upper portion.

Endosperm.—The endosperm is of unequal development, later-
ally as much as 150% in thickness. Harz gives the thickness as
250". Cells of the aleurone layer rectangular, thick-walled, and
filled with fat and protein grains. This layer is followed by re-
serve cellulose. The primary wall persists when treated with weak
solvents. The walls, except the primary, color blue with chlor-
iodide of zinc. The inner portion of the endosperm consists of
. thick-walled, elongated cells.

Embryo.—Cells of the first row smaller than those below; ex-
terior walls thickened more than the lateral; all of the cell walls
consist of cellulose. Cells contain fat and protein grains; starch
grains do not occur, though Harz says they are usually abundant.
In several specimens examined starch was not found even when
potassium hydrate or weak sulphuric acid was used with the iodine.

548 WEED FLORA OF IOWA

Fe

Fic. 421. Microscopic structures of seeds of some leguminous weeds.

I. and V. Yellow Sweet Clover (Melilotus officinalis). 1. White Sweet
Clover (Melilotus alba). III. Black Medick (Medicago lupulina). IV.
Bur Clover (Medicago denticulata).

m=malpighian cells. ll=light line of the same. o=osteosclerid. em=embrya
t=testa. en=endosperm. p=parenchyma. n=nucellus,

.(Drawings by L. H. Pammel.)

MICROSCOPIC STRUCTURE OF WEED SEEDS 549

Bur Clover (Medicago denticulata Willd.).

The seeds of this species agree with those of M. lupulina.

Malpighian cells 35-384 long; the narrow light line occurs be-
low the conical layer; the chromatophores are absent.

Osteosclerids 16-184 long; longitudinal striae well marked.
Cross sections show beyond a doubt that these striae are canals.
The nutrient layer is much compressed.

Aleurone layer of endosperm as in M. lupulina. The mucil-
aginous reserve cellulose not so strongly developed as in the last
species. Treatment with iodine gives no reaction for starch; nor
do blue grains appear when treated with weak sulphurie acid and
iodine, or potash and iodine. An abundance of fat and protein
grains occurs in the cells. Walls of the reserve cellulose color
light blue. Malpighian cells a darker blue.

Sweet Clover (Melilotus alba Lam.).

Testa and endosperm vary in thickness, average 75". Malpighian
cells as long as the thickness of the endosperm and remainder of
testa. :

Malpighian.—Cuticle wavy and well developed; the cuticularized
layer below with small, conical projections, those of two adjoining
cells meeting at the middle lamella of the lateral walls, giving the
layer the appearance of consisting of conelike projections. These
cones are also connected with the small pore-canals. This cuticular-
ized layer is highly refractive. The lhght line consists of a nar-
row but distinct refractive zone below the conical layer. The
refractive zone colors blue with chlor-iodide of zinc. The whole
upper part is more or less refractive. The remainder of the cell
wall contains pigment and is colored blue with chlor-iodide of
zine; the cuticularized layer as well as the conical layer colors
blue. Small canals project into the walls, and in some cases extend
beyond the light line. The chromatophores are irregularly dis-
tributed in the cell cavity, some near the base, others in the center.

Osteosclerid.—Cells with a broad base and a small triangular
intercellular space above; longitudinal pore-canals in the upper -
part of the cell, but these do not extend its entire length.

Nutrient—This layer is much compressed; consists of thin-
walled cells, divided into two parts; cell walls of lower part
thicker. Both layers contain pigment and tannin, the upper more
than the lower. Cell walls consist of cellulose.

550 WEED FLORA OF IOWA -

Endosperm.—The aleurone layer is quite distinct; the cells are
rectangular; cell walls made up of cellulose. The walls of the re-
mainder of the endosperm, except where it joins the embryo, are
thick, consisting of mucilaginous reserve cellulose. Cells of the
internal layer of the endosperm thick-walled, clon sey containing
some protein grains and fat.

Embryo.—Cells of the exterior walls of first row thickened;
smaller than those below. All of the cells contain fat, protein
grains, and small starch grains. Procambial vessels well developed.

Yellow Sweet Clover (Melilotus officinalis Lam.).

Testa with endosperm varying from 260-300 in thickness. The
Malpighian cells of this species are longer than in WM. alba, and
also more abundantly supplied with pigment. The conical pro-
jections are longer. The osteosclerids are longer and nearly as
wide above as below. The longitudinal canals are as conspicuous
and well developed as in that species. Cells of the nutrient layer,
especially in the lower part, are abundantly supplied with pig-
ment and some tannin. The walls of the aleurone cells are thick;
the mucilaginous reserve cellulose and the thick-walled, elongated
cells are not essentially different from the last species. It also
agrees with it with respect to the embryo.

Hairy Prairie Clover (Dalea alopecuroides Willd.) (Parosela
dalea (l.) Britt.).

Testa and endosperm from 150-265 in thickness. Variation is
mostly due to endosperm, which reaches its greatest development
laterally.

Malpighian.—Cells are 36.4" in length. Cuticle prominent;
cuticularized layer not conspicuous; narrow light line near the
cuticle; pores prominent, extending into the walls beyond the
light line. Cell cavity broad at the base, containing protein
erains.

Osteosclerid.—Cells thick-walled, lighter in color than the Mal-
pighian layer. They contain pigment, tannin and protein.

Nutrient—This layer is compressed and the cells are elongated.
Walls color blue with chlor-iodide of zinc. Brown pigment
abundant in the vascular region.

Endosperm.—Aleurone cells nearly isodiametric, containing fat,
and protein; most of the endosperm consisting of reserve cellulose

MICROSCOPIC STRUCTURE OF WEED SEEDS 551

Fie. 422. Microscopic structure of leguminous seeds (Leguminosae).

I. Silky Sophora (Sophora sericea). II. Parosela (Dalea alopecuroides). III.
Common Vetch (Vicia sativa). IV. Stemless Locoweed (Oxvytropis lam-
verti). V. Wild Liquorice (Glycyrrhiza lepidota).

m=malpighian cells. l=light line. em=embryo. o=osteosclerid. p=parenchy-
ma. al=aleurone layer. en=endosperm. en=endosperm reserve cellulose
cells. tr=tracheae.

(Drawings by L. H. Pammel.)

552 WEED FLORA OF IOWA

with prominent pore-canals; the internal layer consisting of
elongated thick-walled cells, with cell cavity much reduced.

Embryo—First row of cells of embryo smaller than underlying,
with thickened outer walls. Cells below with small intercellular
spaces. Reserve material consists of fat and protein grains;
starch is absent.

Stemless Loco Weed (Oxytropis lamberti Pursh.).

Testa and endosperm 170-1754. This, the so-called loco weed, is
said to cause disturbances in animals, but alkaloids have not been
found in the seed or any other part of the plant.

Malpighian.—Cells 40-424 long. Cuticle somewhat uneven; the
narrow well marked cuticularized layer colors blue with chlor-
iodide of zinc; the light line occurs below the cuticularized layer,
and this also colors blue; the remainder of the cell wall takes on
a darker blue color. Cells contain an abundance of pigment,
tannin, and some plastic material.

Osteosclerid.—Cell walls thickened, not prominently I-shaped,
but with an elongated intercellular space.

Nutrient.—Layer consists of thin-walled elongated cells from
ten to twelve rows. Pigment more abundant in lower than in
upper part. Walls color blue with chlor-iodide of zine.

Endosperm.—The aleurone layer consists of thick-walled cells;
the underlying thick-walled ‘cells of the reserve cellulose become
mucilaginous on the addition of water. The internal part consists
of thick-walled, elongated cells. The cells contain protein.

Embryo.—Cells of the first row smaller, with thick exterior
walls; cells below not so compact atid with thinner walls. Cell
walls color blue with chlor-iodide of zine. Starch is absent but
cells contain fat and protein.

Bush Clover (Lespedeza capitata Mx.).

Testa and endosperm 90-100 thick. Light line occurs close
under the cuticle. A large spherical chromatophore occurs in the
pigmented Malphigian cells which is variable as to its position in the
cell. The long pores extend to the middle of the cell. The os-
teosclerids are short. The nutrient layer is compressed, containing
much pigment. Endosperm as in D. stuvei; the aleurone cells are
thick-walled, and the reserve cellulose is mucilaginous. Embryo
as in the other species containing fat and protein but no starch.

MICROSCOPIC STRUCTURE OF WHED SEEDS 553°
Common Vetch (Vicia sativa L.).

This species has been studied by Harz, Tschirch and Oesterle,
Beck, and Sempolowski. Testa irregular, with small projections,
126 thick. Endosperm reduced to a single layer. The presence
of endosperm has been indicated by the above writers. Beck
speaks of an aleurone spot: (Aleurone fleck) in the epidermal cells
of the cotyledons of this and other species of the genus Vicia.

Malpighian.Cells 72-75" long, pointed at the upper end;

cuticle very irregular because of the projections; cuticularized
layer most prominent in the depressions; pores project into the
walls below the light line, and partly connect with the cell cavity;
_the upper part of the cell is not pigmented, or very little. The
light line oceurs just above the pigmented part of the cell. Cell
cavity is large at the base, narrows upward, becoming much con-
stricted below the light line, and above widens again. Small
lateral projections or pores extend into the wall at right angles to
the cavity. A large chromatophore, some pigment, and small
granules occur in the cavity. The walls in lower part of cell are
colored bluish brown.

Osteosclerid.—Cells are thick-walled, 13-16.8- long, longitudinally
striated. Upper and lower ecross-bars nearly equal; the inter-
cellular spaces elongated. Tschirch and Oesterle state that this
layer is not very strongly developed, but in specimens which I
have examined it is well developed. These cells are more or less
variable, as indicated by Harz, who states that they are from
11-13" long.

Nutrient —This layer is differentiated into two parts; the upper
consists of thin-walled, elongated cells with a yellowish pigment;
the cells of the lower part are larger, thin-walled and elongated,
containing a brown pigment.

Nucellus.——This consists of a narrow zone of compressed cells.

Endosperm.—Ocecurs in the form of thick-walled elongated cells
with a narrow eell cavity. Usually only one or two rows of cells.

_ Hmbryo.—The outer row of cells of the cotyledon is continuous.

The exterior walls are thickened; cells below are more loosely ar-
ranged; small intercellular spaces in the angles of the cells; the
epidermal cells contain fat and protein, the others in addition an
abundance of spherical or elliptical starch grains measuring 25
x22.5" to 50x25". Palisade cells wanting.

554 WEED FLORA OF IOWA

Wild Liquorice (Glycyrrhiza lemdota (Nutt.) Pursh.).

Testa and endosperm 490-500" thick. Endosperm variable in
different parts of the seed, but usually well developed.

Malpighian—Cells 70-75" long. Cuticle somewhat irregular;
the light colored cuticularized layer is followed by a narrow but
sharply marked zone, the light line; cell cavity is large at the base,
gradually tapering upward. Pore-canals extend into wall beyond
the ight line. Cells contain pigment and some plastic material.

Osteosclerid.—The I-shaped cells are thick-walled, with small
projections somewhat similar to those shown for Ervuwm lens by
Mattirolo and Buscalioni. The intercellular space is elongated.
The cells attain their greatest development in the hilar region.
All of the cells carry some pigment and plastic material.

Nutrient.—This layer is much compressed and thin-walled; cells
number from four to six rows. Pigment is most abundant in the
lower part of the layer.

Endosperm.—Aleurone layer consists of nearly isodiametric
thick-walled cells. The mucilaginous reserve cellulose is variable
in quantity. Cell walls differentiated into primary, secondary and
tertiary. Internal part of the endosperm consists of thick-walled,
elongated cells. All of the cells contain protein grains.

Embryo.—Cells of the outer row smaller than those within; ex-
terior walls thickened, those below more loosely arranged than the
-epidermal; more compact and with thicker walls than those of
Astragalus meaxicanus. Cells contain fat and protein grains but
no starch.

LINACEAE, FLAX FAMILY.

Common Flax (Linwm usitatissimum L.).

The shining, brownish seeds consist of an outer epidermal layer
of thick-walled cells; walls colorless and stratified; these become
mucilaginous on the addition of water. The cell cavity is very
small, the underlying layer consists of yellowish parenchyma cells.
The third, called the fiber layer by Winton, consists of sclerotic
parenchyma cells with pore-canals, the sclerotic parenchyma fol-
lowed by a layer of colorless cross-cells with thin walls. The
parenchyma cells of the pigment layer follow; these cells are
squarish, pigment yellowish brown. The endosperm follows the

MICROSCOPIC STRUCTURE OF WEED SEEDS 555

Fic. 428. Microscopic structure of the seed of common Flax (Linum usitatis-
simum). :
ep=epidermis. p=parenchyma, underneath thick-walled sclerenchyma cells and
the pigment layer. pi=pigment layer. en=endosperm.
(Drawing by L. H. Pammel and Charlotte M. King.)

pigment layer and consists of 2-6 layers of cells, the walls being
thicker than those of the embryo, and containing fat and aleurone
grains. The epidermal cells of the embryo are squarish, the cells”
underneath on the upper face of the cotyledon are palisade-like.
All of the cells contain fat and protein.

' GERANIACEAE, GHRANIUM FAMILY.
Carolina Cranesbill (Geranium carolinianum L.).

The testa of the smooth small seeds consists of an outer epider-
mal layer, the cell walls not greatly thickened; underlying it
is a single row of elongated parenchyma cells followed by the Mal-
phigian cells; the light line is narrow and occurs in the middle of
the cell; this is followed by a layer of much larger cells with
thick walls. The inner seed coat is much compressed and consists
of several rows of small cells and a single row of large cells. The
walls in both cases are not greatly thickened. The nucellus is
much compressed. The cells of the endosperm are not much longer
than broad. The cells of the outer row or the aleurone layer are
much smaller than those of the second layer.

556 WEED FLORA OF IOWA

pal
Fe wes Se ee
€ 9Gn.

A Z ee en
aa

3Be

Fic. 424. Microscopic structure of the seed of common Geranium (Geranium
carolinianum).
p=parenchyma, malpighian cells below. ll=light line of mal-

ep=epidermis.
pal=palisade cells. it=inner testa. n=nucellus. en=en-

pighian cells.

dosperm.
(Drawing by L. H. Pammel and Charlotte M. King.)

EUPHORBICEAH,* SPURGH FAMILY.
Flowering Spurge (Huphorbia corollata L.).

The outer layer of the seed coat is mucilaginous; the walls of
the cells are thickened and colorless; showing stratification upon
addition of water; the cell contents are dark in color. The granu-
lar layer beneath the mucilaginous cells is well developed; the con-
tents give a blue reaction to iodine. Underneath the granular
layer is a row of slightly elongated thin-walled parenchyma cells;
beneath these are the long palisade-like cells, in which are pores
of less prominence than in HL. marginata and others. Next lie two
compressed layers of thin-walled parenchyma cells.

Spotted Spurge (Huphorbia preslii Guss.).
The outer layer of cells are darkened; these cells are not
mucilaginous. The palisade-like cells are present, as in all the
species.

*The descriptions here given are from a paper by L. H. Pammel, Trans.
Acad. Sci. St. Louis. 5:543. The literature will be found in this paper.

MICROSCOPIC STRUCTURE OF WEED SEEDS 557

Prostrate Spurge (Huphorbia maculata L.).

The walls of the outer cells are dark in color; these cells are
but slightly mucilaginous. The granular layer is not pronounced.
The palisade-like cells resemble those of the other species.

Fie. 425. Microscopic structure of the seeds of the Spurge family (Huphor-
: biaceae).
I. Cypress Spurge (Huphorbia cyparissias). II. Flowering Spurge (Huphor-
bia corollata).
ep=epidermis, in figure II cell-walls mucilaginous. pal=palisade cells. p=
parenchyma cells. ;
(Drawing by L. H. Pammel.)

Yellow Spurge (Huphorbia cyparisstas L.).

The seed shows the usual palisade-like cells with the overlying
and underlying thin-walled parenchyma cells.

MALYVACEAH, MALLOW FAMILY.
Velvet Weed, Butterprint (Abutilon theophrasti Medic.).*

The outer layer a, of the first integument is transformed into a
strongly refractive layer. The second layer is composed of radially
elongated cells. The seed hairs arise from a single cell and are
large and conspicuous. The hairs are spindle-shaped and thin-
walled; they occur mostly at the ends of the seed and are more or
less pressed to it. There is little or no coloring matter in this in-

*From Rolfs, P. H., Bot. Gaz. 1892 :33-39.

558 WEED FLORA OF IOWA

tegument excepting in the base of the hair cells. The palisade
cells, c, are narrow for their length. The cell cavity is not promi-
nent and the nodosity is inconspicuous. The light line is narrow
and occurs near the outer end of the palisade layer. The sub-
palisade portion, d, is made up of two layers of light brown cells.
They are symmetrical and elongated tangentially.

Measurements, seed coats, 1474; outer integument, 134; palisade
layer, 96"; subpalisade, 38.

Shoo-fly (Hibiscus trionum L.).

P. H. Rolfs has made a study of H. militaris, the microscopic
structure of which species closely resembles that:of H. trionwm.
The dark grayish seeds are roughened with tubercular processes,
which contain the ‘‘seed hairs.’? The seed hairs consist of cells
somewhat longer than broad beginning with a broad base, ex-
tending into a several-celled trichome, the terminal portion larger
than remainder of cell. These hairs contain a yellow pigment.
The Malpighian cells occupy about one-half the thickness of the
testa, the cuticle is well developed, the hght line is near the upper
portion of the cell. The cell cavity is spindle-shaped and near
the middle of the cell. The remainder of the testa consists of a
subpalisade portion of parenchyma cells carrying a brownish pig-
ment; underneath it, larger thin-walled cells; walls brownish, a
compressed narrow, brownish layer, the nucellus, n. This is fol-
lowed by the squarish cells of the endosperm.

Common Mallow (Malva sylvestris L.).

The surface of M. sylvestris is rough in appearance. The second
layer, b, of the outer integument, a, has been compressed into a
thin layer and seems to have no definite arrangement. The outer
layer, a, has been elongated radially. In places, these elongated
‘eells have divided forming a double layer of cells. There is no
brown coloring matter in this integument nor is there any between
the integuments. The palisade cells, c, are clear; the walls thick.
The cell cavity occupies about one-third the length of the cells,
the lower end reaching to the middle. The nodosity is promi-
nent. Below the cavity the cells are clear, almost transparent.
The subpalisade portion, d, is usually made up of two layers, at
some places only one, of large dark brown eells.

MICROSCOPIC STRUCTURE OF WEED SEEDS 559

Measurements, seed coats, 122”; outer integument, 274; outer
layer of same, 22”; inner layer of same, 5“; palisade layer, 70#;
subpalisade, 254. (P. H. Rolfs.)

Fie. 426. Microscopic structure of the seeds of some Malvaceous weeds.

I. Shoo-fly (Hibiscus trionum). II. Indian Mallow or Butterprint (Abutilon
theophrasti). III. Mallow (Malva sylvestris). IV. Sida (Sida spinosa).
V. Cheeses or common Mallow (Malva rotundifolia).

ep=epidermal cells. m=malpighian cells. ll=light line. pi=pigment layer. D=
parenchyma cells. pal=palisade or malpighian cells. n=nucellus. en=en-
dosperm. h=trichome. t=plant hair or trichome surface view

(Drawings by P. H. Rolfs.)

Cheeses or Mallow (Malva rotundifolia L.).

The roughened, somewhat velvety, dark grayish seeds consist
of an outer row of rather large, rather thick-walled cells, walls
colorless. This layer is followed by the very long Malpighian
‘cells, which are longer than the cells of the rest of the testa, light
line near the upper part of the cell, lower portion of cell slightly
yellowish. Cavity spindle-shaped near the middle. The dark

560 WEED FLORA OF IOWA

brownish pigment cells of two or three rows. Adjacent to the
pigment layer is the colorless compressed nucellus and the squarish
endosperm cells.

Sida (Sida spinosa L.).

The brownish seeds are minutely roughened. The Malpighian
cells occupy more than one-half of the thickness of the testa, the
cuticle is well developed, the light line occurs near the upper end
of the cells. The cell cavity is spindle-shaped near the lower end
of the cell. The subepidermal layer contains the brownish pig-
ment, the walls of these cells are thickened; the parenchyma cells
of the layer underneath are colorless, the walls are less thickened;
a narrow pigment layer follows. The cells of the endosperm are
thick-walled containing protein grains.

ONAGRACHAH, EVENING PRIMROSE FAMILY.
Evening Primrose (Oenothera biennis L.).

The small, irregular, winged seeds are rough. The epidermal
cells, ep, of the testa are small, thick-walled with minute pore
canals; the underlying parenchyma cells, p, are large, thick-walled
and with small pore canals; these cells reach their greatest develop-
ment where the wings occur. The remaining portion of the testa
consists of four or five layers of cells more or less rectangular.
The nucellus and the endosperm much compressed, outer epidermal
cells of the embryo, em, thin-walled, a little longer than wide.

Bez

Fic. 427. Microscopic structure of the aie. of Evening Primrose (Oenothera
biennis).

ep=epidermis of thick-walled cells. p=thick-walled parenchyma underneath
thinner-walled parenchyma. n=nucellus and below a few layers of cells of
the endosperm.
(Drawing by Charlotte M. King and L. H. Pammel.)

MICROSCOPIC STRUCTURE OF WEED SEEDS 561
UMBELLIFERAH, PARSLEY FAMILY.
Sweet Cicely (Osmorrhiza longistylis (Torr.) D.C.).

The epidermal cells are longer than broad, the outer walls are
thickened, five to six rows of thin-walled parenchyma cells occur
underneath the epidermal layer; the ribs contain the vascular ele-
ments, thick-walled sclerenchyma cells; the testa consists of a
layer of thin-walled. parenchyma eells, p, followed by a layer tan-
gentially elongated and-another of large parenchyma cells, p*, and
the compressed nucellus, n.. The endosperm consists of large thin-
walled cells.

Fic. 428. Microscopic structure of some Umbelliferous weeds.

I. Sweet Cicely (Osmorhiza longistylis). II. Cow Parsnip (Heracleum lana-
tum). III. Wild Carrot (Daucus carota). Underneath, parenchyma cells,
thick-walled sclerotic parenchyma, sectional view to the right.

n=nucellus. p=parenchyma. t=testa. en=endosperm. ep=epidermis. o=oil
duct.

(Drawings by L. H. Pammel.)
36

562 WEED FLORA OF IOWA

Wild Carrot (Daucus carota L.).

The cremocarp consists of an outer epidermis of cells some-
what longer than broad; the underlying cells are of similar struc-
ture except the cells near the inner epidermis, which are much
longer than wide; a large oil duct occurs in each rib. The testa
consists of a single layer of parenchyma cells and a few rows of
compressed elements, probably the nucellus. The endosperm of
thin-walled parenchyma cells contains protein.

Cow Parsnip (Heraclewm lanatum).

An outer epidermis with outer walls thickened. The underlying
parenchyma cells similar, followed by a layer of thick-walled
sclerenchyma cells. The testa of single layer of cells. The en-
dosperm cells contain protein.

ASCLEPIADACEAE, MILKWEED FAMILY.
Milkweed (Asclepias syriaca L.).

The flattened reddish brown seeds consist of an epidermis of
isodiametric cells; the outer walls wavy, and thickened; each cell
with a projecting point, outer walls colorless, contents brownish;
the epidermis is followed by 10-14 rows of thin-walled parenchyma
cells containing a brownish pigment. This layer is followed by

oP

Fic. 429. Microscopie structure of the seed of Milkweed (Asclepias syriaca).
ep=epidermis. p=parenchyma. n=nucellus. em=embryo.
(Drawing by L. H. Pammel and Charlotte M. King.)

MICROSCOPIC STRUCTURE OF WEED SEEDS 563

the compressed perisperm, brownish yellow in color. The endo-
sperm consists of thickish-walled, colorless parenchyma cells, the
outer row smaller than the underlying, the inner layer of smaller
elongated cells. The contents consist of protein and fat. The
inner epidermal cells of the embryo are smaller than the endo-
sperm cells; they contain protein and fat.

CONVOLVULACHAE, CONVOLVULUS FAMILY.
European Bindweed (Convolvulus arvensis L.).

The testa consists of an outer row of short or elongated cells p
with thick walls and brownish contents. This is followed by a
layer of small cells with colorless walls. Contents brownish. The
Malphighian cells m are situated underneath. This is followed by
a layer of parenchyma cells consisting of 8-12 rows of cells. The
endosperm consists of thick-walled colorless cells. The walls in
part mucilaginous.

Fic. 430. Microscopic structure of the seeds of Convolvulaceae.

I. Morning-glory (Convolvulus sepium). II. Cultivated Morning-glory (Ipomoea
purpurea). III. Dodder (Cuscuta epithymum). IV. Bindweed (Convol-
vulus arvensis).

ep=epidermis. m=malpighian cells. ll=light line. p=parenchyma. n=nucellus.
en=endosperm. a8

(Drawings by L. H. Pammel and Charlotte M. King.)

564 WEED FLORA OF IOWA

Wild Morning Glory (Convolvulus sepium L.).

The testa of the seed of the common morning glory consists of
an outer layer of elongated cells containing the blackish pigment
followed by the Malpighian cells with small cell cavity and promi-
nent light line. The colorless parenchyma cells are thick-walled
followed by a compressed indistinct layer, the compressed nucellus
and the endosperm cells.

Cultivated Morning Glory (Ipomoea purpurea (.) Roth.).

The black-brownish seeds are rough. The testa. consists of a
superficial layer of cells with granular brownish contents. The
Malpighian cells m occur underneath; the light line is near the
upper part of the cell, cell cavity small. The cells of the paren-
chyma layer are compressed. The cells of the endosperm are thick-
walled and somewhat mucilaginous.

Dodder (Cuscuta epithymum Maurr.).

The small seeds are minutely roughened and velvety. The outer
layer of the testa consists of large cells with yellowish contents,
the following layer consists of thick-walled cubical or prismatic
cells p, the colorless Malpighian cells m follow. They are elongated
with a small cell cavity. The layer following consists of com-
pressed cells, tangentially elongated. The endosperm layer con-
sists of an outer aleurone layer of nearly square cells. The cells
below are irregular. The endosperm cells contain compound or
simple starch grains and protein.

BORAGINACHAEH, BORAGE FAMILY.
Wild Comfrey (Cynoglossum virginianum L.).

The rough fruits are covered with hooked appendages, the sides
roughened with small colorless points; the epidermal layer is ir-
regular and prominent, in some cells developed into short trichomes,
whose walls are greatly thickened. The epidermal walls and con-
tents are blackish, the underlying sclerotic parenchyma cells have.
thick walls and are blackish. The parenchyma cells of the testa
are thinner walled and colorless, followed by the compressed layer
of the nucellus n. The endosperm cells are longer than broad,
colorless, contain protein and fat.

MICROSCOPIC STRUCTURE OF WEED SEEDS 565

Fic. 431. Microscopic structure of some fruits of the Borage Family (Boragin-

aceae).

I. Stickseed (Lappula echinata) part of fruit or bur. II. Stickseed (Lap-
pula echinata). Enlarged view of epidermal cells showing irregularities in
cell wall and cavity. III. Wild Comfrey (Cynoglossum virginianum).

ep=epidermal cells. n=nucellus. pi=pigment layer. en=endosperm. t=tri-
chomes. ;

(Drawings by L. H. Pammel and C. M. King.)

Stickseed (Lappula echinata Gilibert).

The fruits are rough and provided with hooked appendages,
the cells of the appendages are elongated, thick-walled, the walls
colorless; the cells of the epidermis toward the exterior are very .
irregular with projecting rounded or sharp points, walls colorless.
The epidermal cells are elongated with central cell cavity and
prominent pore canals at right angles with the cell cavity, these
having the appearance of a series of cells one above the other.
The epidermal cells contain a brownish pigment, the underlying
parenchyma cells are thinner walled and also contain a brownish

566 WEED FI.ORA OF IOWA

pigment. The testa is thin, consisting of thin-walled parenchyma
cells with granular contents.

VERBENACEAE, VERVAIN FAMILY.
Hoary Vervain (Verbena stricta Vent.).

Epidermal cells thick-walled; ‘outer cells colorless. Underneath
this lie several layers of pigmented cells, slightly longer than broad.
This layer is followed by rather thick-walled, colorless cells, with
small cell cavity; one or two rows toward the middle are thick-
walled and smaller. Next follow the cells of the embryo.

Fic. 432. Miscroscopic structure of seed and fruit of Vervain (Verbena stricta).
ep=epidermis, thick-walled. p=parenchyma layer. pi=pigment layer of small
parenchyma cells. The two inner layers of cells of the testa.
(Drawings by L. H. Pammel and Charlotte M. King.)

LABIATAE, MINT FAMILY.
Catnip (Nepeta cataria L.).

The small dull brown seeds are finely roughened. The pericarp
consists of an epidermal layer with thin cuticle, on the addition
of water becoming mucilaginous. This layer is followed by under-
lying parenchyma cells, then the Malpighian cells with conspicuous
light line. The cells are colored yellowish brown; underlying this,

MICROSCOPIC STRUCTURE OF WEED SEEDS 567

the testa, consisting of a single layer of cells, thin-walled. The
nucellus of whitish, elongated, rather thick-walled cells, the en-
dosperm differentiated into an outer layer of larger parenchyma
and a compressed inner layer of thick-walled cells. The epidermal
cells of the embryo nearly isodiametric, contain protein and fat.
The epidermal cells of the upper epidermis nearly like the lower,
palisade parenchyma underneath.

Fic. 433. Microscopie structure of seeds of the Mint Family (Labiatae).
I. Catnip (Nepeta cataria). II. Giant Hyssop (Agastache scrophulariaefolia).
ep=epidermis, underneath, parenchyma cells in I and sclerotic parenchyma in
II, the epidermal cells irregular showing some trichomes. scl=sclerotic
parenchyma. en=endosperm. m=malpighian cells. n=nucellus. ll=light
line. p=parenchyma. em=embryo.
(Drawings by L. H. Pammel and C. M. King.)

Giant Hyssop (Agastache scrophulariaefolia (Willd.) Ktze.).

The small pubescent nutlet consists of the epidermal cells of
the pericarp with small unicellular thickened trichomes; cells con-
tain a brownish pigment; the cells of: the layer underneath are
thick-walled, cell wall and cavity contain a brownish pigment.
The Malpighian layer follows, the cells being longer than wide,
the light line near the upper part of the cell. These cells are
yellowish. The testa is compressed and consists of elongated cells,
brownish in color. The endosperm varies in thickness, the cells
are in some cases elongated, in others squarish, and contain fat
and protein material.

568 WEED FLORA OF IOWA
SOLANACHAE, NIGHTSHADE FAMILY.
Horse Nettle (Solanum carolinense L.).

The testa consists of an outer row of cells whose walls are
mucilaginous ; the underlying cells are thick-walled with interven-
ing air spaces broad below and narrow above. The cells of this
layer contain the yellow pigment. The underlying parenchyma
layer is compressed, composed of colorless cells which are longer
than wide; the layer adjacent to the endosperm is compressed
and not clearly defined. The cells of the inner portion of the
endosperm are smaller and contain protein. Cells of embryo are
small and contain protein.

Fig. 434. Microscopic structure of the seeds of some Solanaceous weeds.
I. Jimson Weed (Datura stramoniwm). II. Black Nightshade (Solanum ni-
grum). III. Buffalo Bur (Solanwm rostratum). IV. Horse Nettle (Sola-
num carolinense). V. Ground Cherry (Physalis pubescens).
ep=epidermis. en=endosperm. pal=palisade cells. em=embryo. p=parenchyma. p!=
elongated parenchyma cells.
(Drawings by L. H. Pammel and C. M. King.)

MICROSCOPIC STRUCTURE OF WEED SEEDS | 569
Buffalo Bur or Spiny Nightshade (Solanum rostratuwm Dunal).

The black seeds are irregular on the surface, which is mucil-
aginous; the underlying layer consists of thick-walled cells with
large cavities into which thickened processes extend; the third
layer is also pigmented and consists of squarish cells or elongated,
compressed elements. The endosperm is composed of thick-walled
cells, the outer nearly square, the others elongated. Starch ab-
sent; protein present. The cells of the embryo are smaller, thin-
walled and contain protein and fat.

Black Nightshade (Solanum nigrum L.).

The surface of the yellowish seeds is slightly irregular. The
superficial layers consist of mucilaginous, parenchyma, cells, fol-
lowed by large parenchyma cells with thickened folds. These cells
are, however, variable as to structure and are sometimes short
with folds not evident. The elongated, thick-walled portion of
the testa contains the yellowish pigment. The cell cavity is tri-
angular. The second layer of parenchyma cells is compressed.

Jimson Weed (Datura stramonum L.).

The blackish seeds are rough, surface irregular, cells and walls
of epidermis ep thick; the underlying thinner-walled cells » are
small, longer than broad, followed by an indistinct layer p’, whose
walls are not clearly defined. The layer adjacent to the endosperm
consists of somewhat larger cells also thin-walled. The endosperm
cells e are large, containing protein.

Ground Cherry (Physalis pubescens L.).

The epidermal cells are thick-walled, the outer walls colorless.
These cells contain the pigment. The parenchyma cells of the
second layer are elongated; an indistinct compressed layer follows.
The outer row of the endosperm cells are smaller, containing
protein.

A discussion of the seed coats of this family is to be found in Harz, Samen-
kunde, 2 996-1025.

570 WEED FLORA OF IOWA

SCROPHULARIACEAE, FIGWORT FAMILY.
Mullein (Verbascum thapsus L.).

The minute, roughened seeds are irregular. The epidermal cells
are dark colored, longer than broad and thick-walled. The epider-
mal layer is followed by one or more layers of parenchyma eells,
more numerous in the micropilar region; an indistinct and com-
pressed layer with large intercellular spaces follows, these corre-
sponding to the irregularities on the surface, smaller intercellular

Fic. 435. Microscopic structure of the seeds of the Figwort family (Scrophul-

ariaceae).
I. Moth Mullein (Verbascum blattaria). II. Common Mullein (Verbascum
thapsus).
ep=epidermis. p=parenchyma. al=aleurone layer. en=endosperm. em=em-
bryo.

(Drawings by L. H. Pammel and Charlotte M. King.)

spaces occurring between the larger. The nucellus is compressed,
showing remnants of cell walls. The endosperm consists of an
outer aleurone layer, the walls with pore canals; this is followed .
by cells of the same character. The cells of the embryo are
smaller. The testa of Verbascum blattaria in an undeveloped seed
consists of the epidermal cells with chlorophyll and the SEES
much larger cells also with chlorophyll.

MICROSCOPIC STRUCTURE OF WEED SEEDS 571

PLANTAGINACEAH, PLANTAIN FAMILY.
Common Plantain (Plantago major 1.).

The small, yellowish brown seeds consist of an epidermal layer
of thick black-brownish seeds. The walls on the addition of water
become mucilaginous and expand. The cell cavity is small. The
epidermal layer is followed by several layers and small parenchyma
cells. These cells are usually somewhat compressed and brownish
in color. The pigment layer and endosperm consist of an outer
layer of aleurone cells smaller than the underlying eells. These
cells contain protein grains and starch; the walls have small: pore
canals.

Bre

en

'
t
'
1
wn
:

Fig. 486. Microscopic structure of the seeds of Plantain family.
I. Bracted Plantain (Plantago aristata). II. Common Plantain (Plantago
major). III. Buckhorn (Plantago lanceolata).
1l=epidermal cells showing stratification. c=cell cavity. ep=epidermis. pi=un-
derlying parenchyma cells. 2=underlying parenchyma cells of the testa.
em=embryo. n=nucellus. p=parenchyma cells. en=endosperm.
(Drawings by L. H. Pammel and C. M. King.)

572 WEED FLORA OF IOWA
_ Buckhorn (Plantago lanceolata L.).

The smooth, brownish, elongated seeds consist of epidermal cells
with a small cavity and thick walls; the outer walls become mucil-
aginous on the addition of water. The underlying cells are thin,
blackish, elongated, followed by a brown pigment layer as in the
last species. The aleurone cells and remaining endosperm cells
are of about the same shape and size; the walls are provided with
small pore canals.

Bracted Plantain (Plantago aristata Mx.).

The seeds of this are similar in structure to those of P. lance-
olata. The walls of the epidermal cells are mucilaginous. The
underlying parenchyma cells and the underlying pigment layer
are followed by the endosperm and embryo. The cells of the
nucellus are narrow, elongated, and thick-walled. The eells of
the embryo are isodiametric and are thin-walled. Several species of
the genus have been studied by Harz*. Numerous earlier papers
and references will be found in Pammel’s article in Transactions
St. Louis Academy of Science, 9:91.

RUBIACHAH, MADDER FAMILY.
Bedstraw (Galium aparine L.).

The dry fruit of the common bedstraw is provided with hooked
prickles. The epidermal cells are somewhat elongated, brownish.
The trichomes consist of single hooked cells with pitted walls. The
underlying thin-walled parenchyma cells are elongated. Harz ob-
served mucilaginous cells in this portion of the- pericarp. The
testa is very much reduced, consisting of several layers of thin-
walled cells with granular contents. The endosperm consists of
an aleurone layer, thick-walled cells followed by a thick-walled
irregular layer of cells with pore canals. Contents consist of pro-
tein grains.

*Samenkunde 2; 983.

MICROSCOPIC STRUCTURE OF WEED SEEDS 573

Fic. 437. Microscopic structure of fruit of Bedstraw (Galium aparine).
ep=epidermis. t=testa. t! =trichome. en=endosperm.
(Drawing by L. H. Pammel and Charlotte M. King.)

CUCURBITACEAE, GOURD FAMILY.
Wild Cucumber (Sicyos angulatus L.).

The testa of the brownish seeds consists of elongated epidermal
cells with narrow cell cavities; walls thickened, with pore canals.
The underlying portion consists of a layer of one or two rows of
cells with thin walls, and protein contents; the remaining portion
of the testa is composed of thin-walled cells with large inter-
cellular spaces. The related species, Echinocystis lobata, contains
a thick, pigment layer of brownish sclerotic parenchyma followed
by a thinner layer of thick-walled cells with blackish brown pig-
ment. In this species, as in Sicyos angulatus, frequently portions
of the fruit adhere to the surface. The seed coats of this family
have been described-by Harz.

574 WEED FLORA OF IOWA

Fic. 438. Microscopic structure of seeds of some cultivated weeds.
I. Wild Cucumber or Wild Balsam Apple (Echinocystis lobata). II. Bur
Cucumber (Sicyos angulatus). f
ep=epidermis. ll=light line. p=parenchyma. m=malpighian layer. scl=scler-
otic cells.
(Drawings by L. H. Pammel and C. M. King.)

COMPOSITAE, COMPOSITE FAMILY.
Large Ragweed (Ambrosia trifida IL.).

The so-called ‘‘seed’’ consists of an inyolucre of rather thick-
walled sclerotic parenchyma cells, occurring underneath the
epidermis; some of these cells are radially elongated, others are
spherical in cross section, showing numerous pore canals. The
internal layer of the involucre is composed of nearly isodiametric,
thick-walled, sclerotic cells. The testa consists of a layer of brown-
ish colored cells followed by a layer containing black pigment.
Next within lies a layer of thick-walled, small, nearly colorless
cells, then the compressed layer of the nucellus, followed by the
nearly square cells of the embryo.

MICROSCOPIC STRUCTURE OF WEED SEEDS > 575

Common Sunflower (Helianthus annuus L.).

The microscopic structure of the fruit and seed has been studied
by Hanausek, Harz, Winton and Moeller. The obovoid achenes
are more or less four-sided. The pericarp in some varieties is
nearly black, in others it is striped with white and black. The
pericarp consists of thin porous walls which are dark colored in
the black seeded varieties, although in the varieties with striped
seeds only a part of the cells are colored. Some of the cells are
elongated, forming duplex hairs, which are attached to what
Hanausek called the ‘‘foot cell.’? The underlymg hypodermal
cells of 4-6 rows of cells are thick-walled and porous, the cells ar-
ranged in rows. These contain the blackish pigment, pitchlike in
character. The third layer consists of thick-walled sclerotic
parenchyma cells. These cells are more or less isodiametric. This
layer contains the fibrovascular bundles which occur adjacent to
the thin-walled parenchyma eells. Extending into the sclerotic
parenchyma are radial rows of thinner-walled parenchyma cells.
This layer is followed by large thin-walled parenchyma cells. The
testa consists of thin-walled loose parenchyma cells. The outer or
epidermal cells are roundish and have obscurely beaded walls;
the spongy parenchyma follows and contains the fibrovascular
bundles. The spongy parenchyma is followed by the rectangular
cells of the inner epidermis. The endosperm consists of one or
two rows of aleurone cells. The epidermal layer of the embryo
consists of small, rather thin-walled cells of the cotyledons and
underneath! this on the upper surface are several rows of palisade
cells. These cells contain irregular spherical aleurone grains larg-
er than those in the epidermal cells.

Crownbeard, (Verbesina helianthoides Mx.).

The microscopic structure of the achene includes a series of small,
rather thick-walled epidermal cells, followed by elongated or short,
rather thick-walled parenchyma cells. The pigment layer is com-
posed of thick-walled cells, whose walls contain a blackish pigment.
The testa consists of two layers; an outer of elongated, thick-walled
cells and an inner layer of shorter cells also colorless. The cells
of the embryo are much larger and contain protein grains.

Boot-jack, Spanish Needle (Bidens discoidea (T. & G.) Britton).

The pericarp consists of an outer epidermal layer underlaid by
a similar layer of elongated, thick-walled cells; between which are

576 WEED FLORA OF IOWA

thinner-walled parenchyma cells. The outer layer of the testa
is composed of nearly isodiametric cells, followed by larger thick-
walled parenchyma cells; cells of the lower portion compressed. The
endosperm is much reduced, of elongated cells; embryo with row
of outer cells longer than broad.

cK
J

>
Z ‘
o> 7. AWA ) A
haces (i
Bra \e

<
Ay
Wy
ry Co
1 .
é
/

Fig. 439A Fig. 439 B

Fic. 439. Sunflower (Helianthus annuus).

A. Cross section of outer layers of pericarp. 0, epicarp with h, .hairs; K,
hypoderm; H, fiber bundles separated by m, parenchyma; p, parenchyma
with g, fibro-vascular bundles. X 160.

B. Epicarp with h, twin hairs, in surface view.

After Winton.

Burdock (Arctium lappa L.).

The brownish mottled fruits consist of a thick-walled pericarp,
the outer epidermal layer of thick-walled cells, walls colorless or
but slightly colored; the underlying layer of six or eight rows of
thick-walled cells, not as thick, however, as the epidermal cells.
The first layer carries the brownish or blackish brown pigment.

MICROSCOPIC STRUCTURE OF WEED SEEDS 577

7? OG= rar

par c yo)

em,

SIS®
SEY

Fic. 439A. Miscroscopic structure of some weeds of the Sunflower family
(Compositae).

I. Small Ragweed (Ambrosia artemisiaefolia). II. Verbesina (Verbesina hel-
ianthoides). III. Spanish Needle (Bidens discoidea). IV. Burdock
(Arctium lappa).

ep=epidermis. scl=sclerotic parenchyma, t=testa. n=nucellus. en=endosperm.
em=embryo. pal=palisade cells.

(Drawings by L. H. Pammel and Charlotte M. King.)

The pigment layer is followed by elongated sclerotic parenchyma
with a narrow cell cavity; cells with granular contents. The testa
is thin, cells elongated, cell wall thickened slightly, tinged with
yellow. The testa is followed by remnants of the nucellus. The
parenchyma cells of embryo follow the nucellus.

Wood or Field Thistle (Cirstum discolor (Muhl.) Spreng.).

The microscopic structure of the yellowish gray seeds shows a
elear relationship to Arcttwm; the outer epidermal layer of the
pericarp consists of thick-walled colorless cells, the walls bright

and lustrous; the pigment layer underneath the walls, not nearly
37

578 WEED FLORA OF IOWA

as thick-walled as the epidermal, pigment yellowish. The elong-
ated sclerotic parenchyma cells are yellowish white or nearly color-
less; this layer is followed by the parenchyma cells of the testa and
remnants of the nucellus. The parenchyma cells of the embryo
with numerous small intercellular spaces contain protein and fat.
The fibrovascular bundles are located one at each end of the achene.

Fic. 440. Microscopic structure of the seeds of Thistles (Cirsiwm).
I. and II. Common Wood Thistle (Cirsiwm discolor). III. Iowa Thistle (Cir-
sium iense).
ep=thick-walled epidermal cells. pi=pigment layer. scl=sclerotic palisade cells
with narrow cell-cavity. p=parenchyma cells of testa. t=testa. n=nucellus.
em=embryo. fv=fibro-vascular bundles.
(Drawings by L. H. Pammel and Charlotte M. King.)

Iowa Thistle (Cirstum ioense (Pammel) Fernald).

The microscopic structure of the seeds is similar to that of pre-
ceding, comprising a thick-walled epidermal layer with bright
colored walls and underlying pigment layer, an elongated sclerotic
parenchyma and the testa of small parenchyma cells.

MICROSCOPIC STRUCTURE OF WEED SEEDS 579

Chicory (Cichorium intybus L.).

The microscopic structure of the pericarp and seed of chicory
has been given by Harz and Lavialle. The pericarp consists of
epidermal cells whose outer walls are irregular and cuticularized.
This is followed by a variable number of rows, usually 10-15, of
sclerotic parenchyma, some of the cells of which as observed by

eee e 7
Broce Iria
xt, oa
Bay (fer

Fic. 441. Microscopie structure of the seed of Chicory (Cichorium intybus).
ep=epidermis. scl=sclerotic parenchyma. per=pericarp. t=testa. al=aleu-
, rone layer. en=endosperm.
(Drawing by Charlotte M. King and L. H. Pammel.)

Kraus, contain crystals of calcium oxalate. Beneath are 6-8 rows
of thin-walled, elongated parenchyma. The testa consists of a layer
of large epidermal cells, followed by smaller thin-walled parenchy-
ma, the inner portion much compressed. The aleurone layer is
of elongated cells containing aleurone grains.

Dandelion (Taraxacum officinale Weber). -

Harz has given an account of the structure of the pericarp and
seed. The epidermal cells are irregular, many of the cells pro-
longed into one-celled trichomes, the ribs forming tubercular
processes. The underlying portion containing the thinner-walled
parenchyma and the sclerotic parenchyma cells of the ribs. This
is followed by several rows of compressed, elongated, thin-walled
parenchyma cells. The testa consists of the epidermal layer of
elongated, spirally thickened walls, followed by a compressed layer
of parenchyma cells. The endosperm of one or two rows of
aleurone cells. .

WEED FLORA OF IOWA

580

Saag, Rees

Sam
SSN x,

ile C

nN

()

Dandelion (Taraxacum officinale).

Fic. 442.

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MICROSCOPIC STRUCTURE OF WEED SEEDS 581

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582 WEED FLORA OF IOWA

AMARANTACEAE.

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584 WEED FLORA OF IOWA

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Anatomy of seed of yellow foxtail. Ibid. 1902: 358.

Ueber amerikanische Weizenausreuter. Ztschr. Unters.
Nahr-Genussm. 6:433.

LABIATAE.
Harz, C. D. See Landwirthschaftliche Samenkunde. 2 :866-870.

MICROSCOPIC STRUCTURE OF WHED SEEDS 585

LEGUMINOSAE.

Beck, G. Die Samenkunde einiger Leguminosen. Sitzb. K. K.
Akad. Zu. Wien. 1878. 79. :

Vergleichende Anatomie d. Samen von Vicia und Ervum.
Sitz. d. k. Akad. d. Vissench. Wien. 76 :335-352; 2 pl.

Chalon, J. La graine des légumineuses. I. Cellule de la carapace.
II. Albumen. Soc. des Arts, et des lettres du Hainaut. 1875.
66; pl. 1-3.

Haberlandt, G. Ueber die Entwicklungsgeschichte und den Bau d.
Samenschule bei der Gattung Phaseolus. Sitz. d. k. Akad. d.
Wissensch. Wien. 75:33-47; 2 pl. 1877.

Harz, C. D. See Landwirthschaftliche Samenkunde. 2; 562-736.

Mattirolo, O. Ricerche anatomo-fisiologische sui tegumenti seminali
delle Papilianacee. Nota preventiva. Atti. R. Accad. delle
sei. di Toniro. 24. 1889.

Ricerche anatomo-fisiologische sui tegumenti seminali
delle Papilionacee. I. Anatomia. II. Stor ia di sviluppo dei
tegumenti seminali. JII. Contribuzioni allo studio della fisiol-
ogia del seminali. IV. Bibliographia. Reale Accad. delle Sci.
di. Torino II, 42 :223-318, 359, 445; pl. 1-5. 1892. |

Nadelmann, Hugo. Ueber d. Schleimendosperme d. Leguminosen.
Prings. Jahrb. Wisensch. Bot. 21:609-691; pl. 16-78. 1890.

Pammel, L. H. Anatomical character of seeds of Leguminose.
Trans. St. Louis Acad. Sci. 9:91-263; Tables A-G; pl. 7-35.

The seed coats of Crotalaria sagitalis and Astragalus mollis-
simus. Bienn. Rept. Ia. St. Agr. Coll. and Farm. 13 :17-24;
pl. 59-58. |

On the structure of the testa of several leguminous seeds.
Bull. Torr. Bot. Club. 13 :17-24; pl. 52-58.

Schips, K. Ueber die Cuticula und die Auskleidung der Intereel-
lularen in den Samenschalen der Papilionaceen. Ber. Deutsche.
Bot. Ges. 11:311. 1893.

Schively, Adeline F. Contributions to the life history of Amphi-
carpaea monoica. Cont. Bot. Lab. Univ. Penn. 1:270-363; pl.
19-36.

Schleiden, M. J. Beitrage zur Entwickelungsgeschichte d. Bluthen-
theile bei d. Leguminosen. Nov.-Oct. K. Leopold-Carol. Akad.
Naturf. 19 :59-84; pl. 9-11. p

Winton, A. L. Anatomy of the seeds of Vicia sativa. Winton’s
Microscopy of vegetable products. 251-252.

586 WEED FLORA OF IOWA

MALVACEAE.
Harz, C. D. See Landwirthschaftliche Samenkunde. 2:736-750.
Rolfs, P. H. The seed coats of Malvacex. Bot. Gaz. 17 :33-39.
ONAGRACEAE.
Harz, C. D. See Landwirthschaftliche Samenkunde. 2 :875-878.
PHYTOLACCACEAE.
Harz, C. D. See Landwirthschaftliche Samenkunde. 2:1088-1031.
PLANTAGINACEAE.
Harz, C. D. See Landwirthschaftliche Samenkunde. 2 :982-987.
Winton, A. L. Anatomy of plantain seeds. Microscopy of vegeta-
ble products. 163.
Uloth, W. Ueber Pflanzenschleime und seine Entstehung in der

Samenepidermis von Plantago maritima und Lepidum sativum.
Flora. 58 :193-200, 209-216; pl. 6. 1885.

POLYGONACEAE.

Harz, C. D. See Landwirthschaftliche Samenkunde. 2:1101-1113.

Sirrine, Emma. Structure of the seed coats of Polygonacez. Proc.
la. Acad. Sei. 2:128-134; pl. 7-9.

Winton, A. L. Anatomy of seed of black bindweed. Rept. Conn.
Agr. Exp. Sta. 1902 :340-352. Winton’s Microscopy of vege-
table products. 157-158.

RANUNCULACEAE.

Harz, C. D. See Landwirthschaftliche Samenkunde. 2 :1063-1074.
Winton, A. L. Anatomy of Ranwnculus arvensis. Microscopy of
vegetable products. 152-154.

SAPINDACEAE.

Guérin, M. P. Développement de la graine et in particulier du
tégument séminal de quelques Sapindacées. Jour. de Bot. 15;
336-348.

SCROPHULARIACEAE.

Bachmann, E. Die Entwicklungsgeschichte und der Bau der
., Samenschalen der Scrophularinéen. 179. Halle, 1880.
Harz, C. D. See Landwirthschaftliche Samenkunde. 2 :966-973.

SOLANANCEAE.

Harz, C. D. See Landwirthschaftliche Samenkunde. 2 :997-1025.

MICROSCOPIC STRUCTURE OF WEED SEEDS 587

UMBELLIFERAE.

Harz, C. D. See Landwirthschaftliche Samenkunde. 2:1030-1063.
Winton, A. L. Anatomy of the seeds of wild carrot. Microscopy
of vegetable products. 158-159.
URTICACEAE.

Harz, C. D. See Landwirthschaftliche Samenkunde. 2:978-982.
Winton, A. L. The anatomy of certain oil seeds with especial
reference to the microscopic examination of cattle foods. Conn.
Agr. Exp. Sta. 1903. 175-180.
Microscopy of vegetable products. 212-217.

CHAPTER IV.

MORPHOLOGY OF LEAVES
AND FLOWERS

By

J. N. MARTIN

CHAPTER IV.

LEAVES.

INTRODUCTORY STATEMENT.

Leaves are distinguishable into primary and secondary. The pri-
mary leaves arise directly from the first cells produced by the
division of the fertilized egg and in seed plants are called cotyle-
dons. They are usually transient, and not rarely are so distorted by
acting as storage places for reserve food that they do not function
as foliage leaves at all. The secondary leaves arise upon the sides
of the stem and are the ordinary foliage leaves of the plant. They
are very important organs in connection with the work of nutrition.

PARTS OF A LEAF.

In the typical foliage leaf there are three parts—the expanded
portion which is called blade or lamina, the leaf stalk (petiole),
and a pair of appendages at the base of the petiole known as
stipules.

Fic. 443. Apple leaf; b, blade; p, petiole; s, stipules.
(After Thomé.)

592 WEED FLORA OF IOWA

In some cases, as in the Hare’s-ear mustard, (Conringia orient-
alis) and in the upper leaves of Canada thistle (Cirsium arvense)
the petiole is absent and the blade is directly attached to the stem.
Such leaves are designated as sessile.

Fie. 444. Sessile leaf of Thistle.
(After Thomé.)

The stipules are small leaf-like structures which appear at the
place where the leaf is attached to the stem. They are very often
absent but are conspicuous in the cinquefoils, vetches and other
members of the rose and pulse families.

VEINING.

The blade of the leaf is traversed by a frame work of fibro-
vascular bundles known as veins. In the leaves of grasses, sedges,
and rushes, the veins run more or less parallel from the base to
the tip of the leaf. These leaves are the parallel-veined type. In
the leaves of most of our common weeds, the veins are branched so
as to form a network. These are the netted-veined type.

Palmate and pinnate veining.—Netted-veined leaves are palmately
veined when the primary ribs radiate from the base of the petiole
as in the great ragweed. If there is only one midrib from which
smaller ribs extend both ways, as in dandelion, dock, goldenrod,
etc., the veining is said to be pinnate (meaning featherlike).

LEAF ARRANGEMENT.

Sometimes as in dandelion and evening primrose, the stem does
not appear above ground or is late in appearing and the leaves at
the surface of the ground are called radical leaves in distinction
to the stem or cauline leaves.

MORPHOLOGY OF LEAVES AND FLOWERS 593

Fig. 4451 Fig. 44511

Fic, 445. I. Vetch. (Lathyrus aphaca), showing opposite leaves; r, tendril; b,
flower; f, fruit. Stipules performing the function of leaves.
II. Grass type of leaf; L, leaf blade; G, leaf sheath; Lig, ligule.
‘ (After Thomé.)

Leaves are usually arranged so as to secure the best exposure to
the light. In the milkweed there is a pair of leaves at each node

and the two leaves are on opposite sides of the stem. Here the
leaves are said to be opposite.

Fig. 446. The clinging stem of the Bindweed, showing the alternate leaves.
(After Thomé.)
38

594 WEED FLORA OF IOWA

In the asters, ironweed, goldenrods, lamb’s quarter, ete., there
is only one leaf at each node, and they are spoken of as alternate.
In some cases several leaves appear at each node in a whorl. Such
examples of whorled or verticillate leaves are found in the bed-
straws and Joe Pye weed.

BRANCHING.

The outline of a blade is extremely various. When the general
outline is completely filled out and the margin represents an even
line, the leaf is said to be entire. Examples of such leaves are
found in water pepper (Polygonum hydropiper), mild water pepper
(P. hydropiperoides), Pennsylvania smartweed (P. pennsylvani-
cum), ete. : |

Fic. 447. Leaf of the Privet plant showing entire margin.

To designate the amount and character of the branching, the
following terms are used:

Fig. 4481 Fig. 44811 Fig. 448'II Fig. 4481V

Fic. 448. I. Triangular, lobed leaf of the Notch-weed. II. The reniform or
kidney-shaped leaf of Ground Ivy, illustrating wavy margin. III. Arrow-
shaped leaf of Bindweed. IV. Spear-shaped leaf of Sorrel.

(After Thomé.)

MORPHOLOGY OF LEAVES AND FLOWERS 595

Wavy margin, when the margin forms a wavy line bending
slightly inward and outward in succession, as in the bitter dock
(Rumex obtusifolius).

Fig. 449 T Fig. 449 II Fig. 449 III Fig. 449 1V Fig. 449 V
- Fic. 449. I. Leaf of Daisy, spatulate in shape with a serrate margin. San
Spiny-pointed, serrulate leaflet of alfalfa. III. Wavy-margined leaf of
Pigweed (Amaranthus). IV. Ovate, dentate leaf of Snowball. V. Serrate
leaf of Hen-bit. ;

(After Thomé.)

Toothed or dentate, when the margin is cut into sharp teeth and
the teeth point out, as in the lower leaves of the daisy fleabane
(Erigeron annuus).

Fic. 450. Cleft and pinnatifid leaves of Wild Lettuce.
(After Thomé.)

596 WEED FLORA OF IOWA

Serrate, when the teeth point forward, as in the common sun-
flower (Helianthus annuus).

Serrulate, when the margin is finely serrate as in milk purslane
(Euphorbia maculata).

Crenate, when the teeth are broad and rounded as in the common
mallow (Malva rotundifolia).

100
ONONN

HHH

Fig. 451 1 Fig. 451 II Fig. 451 It

Fic. 451. Compound leaves. I. Leaf of Clover with three leaflets. I1.
Pedately divided leaf of Dragon Root. III. Pinnate leaf of Locust with
19 leaflets.
(After Thomé.)

Lobed, when the leaf is deeply cut, as in the great ragweed. The
projecting portions are then called lobes. When the incisions are
sharp the term cleft is often used; the leaf is pinnatifid when the
incision extends almost to the midrib, as in the prickly lettuce
(Lactuca scariola) ; it is pinnate when the incisions have extended
to the midrib and each separated portion takes the character of a
leaf. Each of the smaller portions is a leaflet, and the leaf is now
considered compound. The spotted cowbane (Cicuta maculata),
spring vetch (Vicia sativa) and cinquefoil (Potentiula monspelien-
sis) are good examples.

MORPHOLOGY OF LEAVES AND FLOWERS 597

Fig. 452 I Fig. 452 II

Fig. 452. I. Wedge-shaped leaflet of Horse Chestnut. II. Pointed leaf of
the Wall Pellitory.
(After Thomé.)

All of the above marginal characters may characterize the lobes
of a simple leaf or the leaflets of a compound leaf.

LEAF STRUCTURE.

Before considering the work of the leaf it will be necessary to
become acquainted with its structure.

The leaf is covered with an epidermis which is composed of com-
pact layers of cells, so modified as to protect the more delicate
inner parts. The epidermis may be peeled off as a delicate trans-
parent skin. A microscope shows that this transparent skin is
made up of many cells, so closely fitted together as to make a contin-
uous sheet or covering. Many slitlike openings between two cres-
cent-shaped cells (guard cells) appear quite evenly distributed in
the epidermis. The opening and guard cells constitute the stoma
(plural stomata) which really means mouth. These numerous
openings are passage ways into the interior of the leaf and per-
mit interchange of gases between outside air and the air in the
leaf interior. The guard cells can change their shape and so vary
the size of the opening. In horizontal leaves the stomata are chiefly
and sometimes exclusively on the lower surface, a fair average
number being about 62,500 to the square inch. .

598 WEED FLORA OF IOWA

O)
pOwCOEDS f
aSnases

avaly

d
p

Fic. 453. I. A cross section of a leaf of Peppergrass (Lepidium) showing
the upper epidermis (e), the lower epidermis (é), stoma (s), the chlor-
enchyma (c) consisting of closely placed palisade cells (p) and more
loosely placed spongy tissue (f), and a vascular or conductive tract (v)
With bundle sheath (b), hadrome or xylem (h), and leptome or phloem (1).

II. Surface view of stoma from Haster Lily; g, the kidney-shaped guard cells en-

closing the stomatal aperture (Ss); b, the subsidiary cells.

III. Cross section of stoma; g, guard cell; s, central slit; 0, outer slit; i,

inner vestibule; c, stomatal cavity ; b, subsidiary cell.

IV. Surface view of a grass stoma (Poa pratensis) showing the guard cells
(g), With their dumb-bell-shaped lumina; b, subsidiary cells with prominent
nucellus (n).

V. Median cross section and cross section through end of stoma of Poa annua;

g, guard cell lumina; b, lumina of subsidiary cells.

VI. <A cross section of a leaf of blue violet (Viola cucullata) showing a single

row of elongated palisade cells (p), and the loose spongy tissue (f).
(Drawings after Cowles modified by Charlotte M. King.)

A eross section of a leaf will show the interior filled with a mass
of thin walled cells containing green bodies (chloroplasts). This
inner mass of thin walled cells is called the mesophyll and is the
food making tissue of the leaf. In the leaves of most weeds the
cells just under the upper epidermis are much elongated and stand
at right angles to the epidermis. These elongated cells are known
as the palisade-cells. Between the palisade-cells and lower epi-
dermis is the spongy tissue made up of irregularly shaped cells,
so loosely joined as to form a system of intercellular spaces which
permit the circulation of gases through the interior of the leaf.
In the lower epidermis are seen the stomata with the air cham-
bers beneath. Scattered through the mesophyll are the cross sec-
tions of veins and veinlets which form the frame work of the leaf
and conduct materials to and from the green working cells.

MORPHOLOGY OF LEAVES AND FLOWERS 599

hse)
EOE

Fic. 454. Section of leaf of Bromus mollis. Car, mid-nerve; L, leptome; H,

. hadrome; B, bulliform cells; Ste, stereome; CB, chlorophyll bearing par-
enchyma; HC, epidermal cells; Tri, trichone.
(Sirrine and King.)

FUNCTION OF LEAVES.

Photosynthesis. This is the process by which sugar and starch
are produced for the plant. It is really a process of food manufac-
ture by which raw materials are made into plant food and is an
exceedingly important one, for upon it depends the lives of all
plants and animals.

Tf an active leaf be submerged in water in the sunlight, bubbles
will be seen continuously forming on the leaf surface and rising
through the water. If light is excluded, the action will cease, and
by increasing and decreasing the amount of light, it will be found
that the process varies with the amount of light. An examination
of this gas will show that it is oxygen. It has also been found that
at the same time the oxygen is given off by the leaf, carbon dioxide
(CO,) is taken in, and that the outgo of oxygen and intake of car-
bon dioxide have a close relation.

600 WEED FLORA OF IOWA

The formula for sugar shows that it is composed of three ele-
ments, carbon, hydrogen, and oxygen. These elements are furnished
by the carbon dioxide (CO,) which is taken in from the air, and
the water (H,O) which is taken from the ground by the roots and
conducted to the leaf tissue by the vascular bundles of the plant.
Although CO, and H,O furnish the necessary elements for sugar
and starch, these are only the raw materials and some agent or fac-
tory is needed to cause these elements to combine and to combine
in the right proportions. These factories are the chloroplasts, which
give the green color to the entire leaf. The green pigment (chloro-
phyll) is the active agent of the chloroplast in the manufacture
of sugar. The process by which these raw materials are combined
is not well understood, and it seems that several simpler products
are formed before sugar is produced. We know that CO, plus
H,O forms carbonic acid (OH. COOH). The carbonic acid is prob-
ably reduced to formaldehyde (H. COH). If six molecules of for-
maldehyde were properly combined we would have one of the sim-
ple sugars (H,C,O,H,) or better written (C,H,,0,). Two mole-
cules of the simpler sugars combined with one molecule of water
eliminated will give cane sugar—C,H,,O, plus C,H,,O,—Cane
sugar C,,H,,0,, plus H,O. By a further synthesis starch is pro-
duced.

When formaldehyde is produced as described above, oxygen is
eliminated and this forms the escaping bubbles from the submerged
leaf.

In this process of photosynthesis, the chloroplasts constitute the
factory, carbon dioxide and water furnish the raw materials, sugar
and starch.are the products, and sunlight is the necessary condition
without which the machinery will not run.

Respiration. Plant cells as well as animal cells have much work
to do and in order to perform work, energy is needed. Plant cells
transform material into cell walls, increase and repair protoplasm,
divide and do many other things which require energy. This work
never ceases as long as the plant lives. The external indication of
it is the absorption of oxygen and the giving out of carbon dioxide.
This exchange is spoken of as respiration. It will be noted at once
that this is exactly the reverse of what takes place in photosynthe-
sis. During the day both carbon dioxide and oxygen are being
both absorbed and eliminated. Photosynthesis and respiration are
independent processes and must not be confused.

MORPHOLOGY OF LEAVES AND FLOWERS 601

Transpiration. We are familiar with the fact that the air is
continually taking up water in the form of vapor. A dish filled
with water and exposed to the air in the laboratory or out of doors
will soon become dry. We hang wet clothes upon the line so that
the air will take up the water which they contain. When we look
into the physics of this process, we find that the water is really the
active agent, and that it is continually changing into vapor and
passing into the air. This process of changing into vapor we call
evaporation, and its rate depends upon temperature, the amount
of moisture already present in the air, and atmospheric pressure.
This same process of evaporation goes on in the leaf, for the air
surrounds the leaf and fills the intercellular spaces within. This
continuous loss of moisture from the leaves is called transpiration.

As seen in photosynthesis, water must be present in the leaf cells
in sufficient quantity or the process of food making will be hindered.
Water is further needed for dissolving and transporting food ma-
terials. It is evident that transpiration is continually diminishing
this quantity of water which is so necessary and if the supply, which
is furnished from the ground through the roots and stems, does not
equal the loss, disaster will come to the plant. So far transpira-
tion seems to be only a detriment to the plant. It is thought to be
of use in that it increases the flow of the water from the soil and
through the plant and thus increases the amount and better dis-
tributes the salts secured from the soil.

It is remarkable how well most weeds can thrive, when economic
plants are suffering severely from transpiration. This may be due
to protective modifications which cut down transpiration or to the
ability to supply the loss through a more efficient root system.

One of the harmful effects of weeds is the taking from the soil
of the water which economic plants need. According to careful
estimates a sunflower (Helianthus annuus) six feet high transpires
on the average about 1 quart per day. A grass plant has been found
to give off its own weight of water every twenty-four hours in
hot, dry summer weather. This would make about 614 tons per acre
or more than one thousand gallons every twenty-four hours for
ordinary grass fields, or rather about 200 gallons for a plot about
the size of a city lot. From the above figures we can form some
notion of the immense loss of water from the soil through weeds, and
see how weeds can retard the growth of economic plants.

602 WEED FLORA OF IOWA

LEAF PROTECTION.

Such an important organ as the leaf, with its delicate active tissue
well displayed, is exposed to numerous dangers. Chief among these
dangers are excessive transpiration and intense light. By regu-
lating the opening in the stomata which are the chief passageways

Fig. 455 I Fig. 455 II

Fig. 455 V Fig. 455 [V Fig. 455 IIL

Fic. 455. Some protective structures of leaves and stems. JI. One-celled hair
of the Pelargonium. II. Multicellular hair of Geranium. III. Scale of
Oleaster (Hlaeagnus). IV. Prickle from common Hop. V. _ Stinging
hair of Nettle.

(After Thomé.)

MORPHOLOGY OF LEAVES AND FLOWERS 603

for the escaping moisture, the leaf is able to check transpiration.
The various epidermal modifications which are quite common among
the weeds afford protection. In some cases this consists of a waxy
layer on the outside of the epidermis as in some milkweeds and some
species of wild lettuce. This layer of wax prevents the escape of
moisture, and protects the chlorophyll-bearing tissue of the leaf
from the intense light rays. i

Another very common protective structure upon the leaves is
to be found in the great variety of hairs developed by the epidermis.
In the mullein the hairs are.so prominent that they form a felt-
like covering. Among the cinquefoils and thistles, the hairs are
usually not branched as in the mullein and the covering is not so
dense.

Fic. 456. Urticating hairs and cutting leaves. a, urticating hair of Nettle;
b, bristle of Bugloss; c, barbed margin of a leaf of Sedge; d, barbed margin
of a leaf of Grass.

All stages from those in which the hairs are very small, giving
the leaf a downy appearance, up to the extreme case in the mullein,
can be found among the weeds.

604 WEED FLORA OF IOWA
FLOWERS.

A satisfactory definition of a flower has not yet been agreed
upon by botanists. For this reason it seems better to describe a
flower rather than attempt to define it.

Fic. 457. Complete flower; cal, calyx; cor, corolla; p, pistil, and s, stamens.
(After Thomé.)

A complete flower consists of four cycles or sets of organs—sepals,
petals, stamens and pistils. The sepals taken together constitute
the calyx; the petals taken together constitute the corolla.

Since the cells of the stem most active in forming new organs lie
in the tip, it seems most natural that the organs appearing last,
would be at the stem tip and that the age of organs would increase
as their distance from the stem tip. According to this scheme, the
succession of floral sets would be sepals, petals, stamens and pistils.
This is probably the order of succession in many flowers, but many
exceptions have been found. In shepherd’s purse (Capsella) the
petals are last to appear, while in the dandelion and other com-
posites the sepals are last to appear.

Fie. 458. Diagrammatic cross section of a perfect flower. St, ovary showing
two cells; S, stamens; B, corolla; K, calyx.
(After Thomé.)

MORPHOLOGY OF LEAVES AND FLOWERS 605

Since the work of the flower is to produce seed, and seed forming
is due to the co-operation of the stamens and pistils, these are
known as the essential organs of the flower. A flower is a perfect
flower if it contains both of the essential organs. The simplest

Fic. 459. Essential organs of the flower of the Black Mustard. a, two short
stamens; b, four long stamens. Pistil is enclosed by the stamens; the
filiform body is the filament of the stamen; the enlarged portion of the
stamen is called the anther.

5 (After 'Thomé.)

flower would have one stamen or one pistil and no corolla or calyx.
Imperfect flowers are designated as staminate when they contain
stamens, but no pistils; pistillate when they contain pistils but no-
stamens. The term ‘‘bisexual’’ is applied to the flower which con-
tains both stamens and pistils. This is the most common type of
flower.

Fic. 460. Irregular flower of a leguminous plant, dissected so as to show the
difference in shape and size of petals.
(After Thomé.)

Plants, such as ragweed and corn, which have pistillate and
staminate flowers (i. e., pistils and stamens in separate flowers but
both kinds of flowers on the same plant) are monoecious (one house-
hold). Such plants as the red campion (Lychnis dioica), mulberry,
willows and poplars, which bear the pistillate flowers on one plant
and staminate on another are dioecious (two households). A plant

606 WEED FLORA OF IOWA

Fic. 461. II. Staminate flower of the Hazel showing the stamens and bracts.
III. Pistillate flower showing pistils and enclosing bracts. IV. Style and
two stigmas. Catkin at middle of stem containing the staminate flowers;
female flower at top of stem. The Hazel is a monoecious plant.

(After Thomé.)

which bears some perfect flowers and some staminate or pistillate |
only, is polygamous.

Fic, 462. Longitudinal section through the hypogynous flower of the Pink, show-
ing the attachment of floral parts.
(After Thomé.)

MORPHOLOGY OF LEAVES AND FLOWERS 607

Fie.

463. I and III. Staminate and pistillate catkins of the Willow. II and IV.
Staminate and pistillate flowers. V. Cross section of ovary showing the
one -cell, two placentae and ovules. VI and VII show opening of pod
and character of the seed. Since the male and female catkins are borne
on different trees, this plant is dioecious.

(After Thomé.)

608 WEED FLORA OF IOWA
Fig. 464 I Fig. 464 II Fig. 464 IIT Fig. 464 IV

Vic. 464. Flowers with petals joined (gamopetalous). I. Globularia. II.
Jasmine. III. Borage. IV. Ground Ivy.
(After Thomé.)

Fic. 465. Gamosepalous and gamopetalous flower of Jamestown or Jimson Weed.
(After Thomé.)

MORPHOLOGY OF LHAVES AND FLOWERS 609

FLORAL ENVELOPES AND THEIR CHARACTERS.

The sepals and petals constitute the two floral envelopes. The
envelopes, taken together, are sometimes called the perianth. This
is especially true in the lily family where the two envelopes do
not differ much in shape and color. Floral envelopes are not es-
sential and one or both may be absent. If only one is absent, it is
the corolla, and the flower is apetalous. In the grasses and sedges
there is no true perianth but the essential organs are enclosed by
chaff-like bracts and glumes.

Fig. 466 I Fig. 466 II

Fic. 466. I. Flower of oats showing the grass type of floral envelopes. G,
empty glume; Pe, lemna bearing an awn A; pi, palea; F. S., sterile flower.
Between lemna and palea are pistil and stamens.

II. Flower with lemna removed, showing palea and the small bracts (lodicules)

at the base of the pistil and stamens. ay
(After Thomé.)

Stamens.—The stamens surround the pistils and their number is
various. They may be opposite the petals or alternate with them.
In the mustards and buttercups the stamens are inserted on the
receptacle. When they are inserted on the corolla as in the morning-
glory, they are epipetalous. Stamens are usually distinct or free
from each other. When they are united by their filaments into one
set, as in the mallow family, lupines and lobelia, they are mona:
delphous (one brotherhood). If united into two sets as in clover,
they are diadelphous (two brotherhoods). More sets would be

designated by tri-, tetra-, ete.
39

610 WEED FLORA OF IOWA

Fig. 467 I Fig. 467 II Fig. 467 Lil Fig. 467 IV
Fic. 467. I. Flower of Ground Ivy with stamens differing in length. II. Mallow
with monadelphous stamens. III. Orange with polydelphous stamens. IV.
Clover with diadelphous stamens.
(After Thomé.)

Relation of the attachment of floral envelopes and stamens to the
pistil—An examination of the floral sets in shepherd’s purse (Cap-
sella) or mustard (Brassica alba) will show that sepals, petals and
stamens are inserted on the receptacle below the ovary. This flower
is hypogynous (i. e., parts under the pistil). When the petals and.
stamens are joined to the calyx, the flower is perigynous (1. e., parts
around the pistil). In such flowers as the evening primrose and
those of the composites, the: calyx is adherent to the ovary and the
corolla seems to arise from the top of the ovary. Such a flower
is said to be epigynous (parts on the pistil).

Fic. 468. Perigynous flower of the Rose.
(After Thomé.) fi

Arrangement of flowers (inflorescence) —Flower arrangement
is of three classes; namely, indeterminate, when the flowers arise
laterally and successively as the floral axis elongates; determinate,
when the flowers arise from the terminal buds and thus check the

elongation of the floral axis; and mixed, when these two are com-
bined.

MORPHOLOGY OF LEAVES AND FLOWERS 611

Fie. 469. Strap-shaped and tubular flowers from the head of Squaw Weed
(Senecio). The corolla and calyx appear to arise from the top of the
ovary. Such a flower is epigynous and the free portion of the calyx is
called DENSIOUNS:

(After Thomé.)

Flowers may arise singly, as in silverweed (Potentilla anserina),
and are then designated as solitary. If in the axils of ordinary
leaves, they are axillary and ‘solitary.

A raceme is that indeterminate inflorescence i in which the flowers
are stalked and arranged along the sides of a floral axis. The
shepherd’s purse has the raceme type of inflorescence. New flowers
are continuously arising at the top as the floral axis elongates.

Fie. 470. Solitary, funnel-shaped floes of field Bindweed.
CAteer Thomé. ) ;

If the inflorescence is ofthe raceme type with the exception that
the flowers have no stalks, as in the plantain, we have the spike. .

612 WEED FLORA OF IOWA

Fig. 471 III Fig. 471 1V

Fie. 471. Types of inflorescence. I. Raceme of Currant. II. Umbel-like
inflorescence of Cherry. III. Head of Clover. IV. Umbel of Parsley.

If the lowest pedicels or flower stalks are elongated (or the upper
ones remain short) so that the cluster is convex or nearly flat on
top, we have the corymb type of inflorescence.

In the wild carrot, common yarrow, and parsley family in gen-
eral, the axis of the corymb is so much shortened that all pedicels
seem to start from the same point and resemble the rays of an in-
verted umbrella. This is the umbel.

In the clover (Trifolium procumbens) the flower axis is short
and the pedicels of the flowers are either short or absent. This
causes the flowers to be crowded into a roundish cluster which is
called a head.

MORPHOLOGY OF LEAVES AND FLOWERS 613

Fic. 472. Close head of a composite.
(After Thomé.)

WV

Tig. 473. Close head of the Dandelion,
(After Thomé.)

614 WEED FLORA OF IOWA

The flower axis is so much shortened in the dandelion, sunflower
and composites in general, that it may be a concave, flat, or conical
surface. The flowers are crowded upon this ‘surface, and the en-
tire group is surrounded by one or more rows of leaf-like bracts
which form the involucre. This is the close head or composite
type of inflorescence. .

Fic. 474. Milkweed with flowers in umbels.

In many eases, as in field sorrel and in five-finger (Potentila
norvegica), the oldest flower of the floral axis is terminal and all
later flowers must arise from axils below. This is the determinate
type of inflorescence and this type of flower cluster is called a cyme.

MORPHOLOGY OF LEAVES AND FLOWERS 615

Fig. 4751 _ Fig. 47511 Fig. 475 III

Fic. 475. Flower of Milkweed, showing the peculiar hooded and horned stamens.,.
I. Flower. II. Stamen. IIL Pistil with adhering pollen masses. IV.
Pollen masses or pollinia.

(After Thomé.)

THE DEVELOPMENT OF A STAMEN AND ITS FUNCTION IN SEED
PRODUCTION.

Every one knows that the pollen produced by the stamens has
an important part to play in seed production. It is for this rea-
son that the stamen is considered one of the essential organs of
the flower.

There is so little variation in the general development of stamens
in the higher seed plants that the history of a stamen from any
weed will suffice for all. ‘

A mature stamen consists of a stalklike portion, the filament,
and the pollen-bearing portion, the anther, which is borne on top
of the filament. The filament may be variously modified or even
wanting.

Fig. 476. Cross section of anther showing pollen sacs. A. pm, pollen mother
cells; t, food cells. B. Pollen grains mature and being shed.
(From Coulter, after Baillon & Luerssen.)

An anther appears distinctly four lobed. If a cross section of a
young anther be made, four distinet regions will be found, one in :
each lobe or a pair on each side of the axis. These four distinct -

616 WEED FLORA OF IOWA

regions are conspicuous because the cells contained are larger and
have a denser content. Hach of these cells will produce four pollen
grains and for this reason are called pollen mother cells.

Surrounding each group of pollen mother cells is usually one
layer of cells whose content is quite dense. These are sacrificed
as food material for the pollen mother cells and are designated as
tapetal cells.

After the pollen grains are formed, they lie loose in these cavities.
Hach cavity is considered as a case or angium and since a pollen
grain is a spore, this case is called a sporangium.

The partition between each pair of sporangia usually breaks
down, and two spore-containing cavities are formed. These are
generally called pollen sacs. The pollen sacs are now ready to
open or dehisce as the process is called. This is due to especially
modified cells, which produce such strains through the variation
of moisture, that usually longitudinal slits or terminal pores are
produced.

Fic. 477. Thrift. ov, ovary; s, style; st, papillary stigmas.
(After Thomé.)

The pollen is now either by wind, insects, or water carried to
the stigma of the pistil where it begins the performance of its
important function. This process of transference is pollination.
An examination of a pollen grain at the time of pollination will
usually show that it has two nuclei; one of these has to do with
the production of a tube which traverses the tissues of the pistil
and furnishes a passage way to the embryo sac which contains the

MORPHOLOGY OF LEAVES AND FLOWERS 617

cells to be fertilized. The other nucleus of the pollen grain pro-
duces two small nuclei which are called sperms. These sperms
pass down the pollen tube to the embryo sac and fertilize the egg
and endosperm nucleus.

THE PISTIL AND ITS FUNCTION IN SHED PRODUCTION.

' A flower may have one or more pistils which occupy the center
of the flower. They are the last to appear, since the order of
development is usually sepals, petals, stamens, and pistil.

DAD. Liye

if 13 ANNE) yy fh.
X NN
‘ i Vy yg,
\ a GYYH 4
Wy /
\ EB.
4,

La

Fic. 478. Iris with petal-like stigmas.
(After Thomé.)

A complete pistil consists of three parts—the expanded base
which bears the seed and is called ovary (or ‘‘egg-case’’) ; the ex-
panded portion at the top, or the stigma; the portion that connects
the ovary and stigma, the style.

The style is not an essential part of the pistil and may be absent
without disturbing the function of the pistil.

The stigma has on its surface many minute papillae which re-
tain the pollen and excrete a sweetish, sticky fluid which serves
as a nourishment and stimulant for the pollen grain.

618 WEED FLORA OF IOWA

Fic. 479. Corn-poppy with a shield-shaped stigma. capping the ovary.
(After Thomé.)

If we cut a cross section of the ovary of the May apple, we find
within, a cavity bearing on one side a projection to which are at-
tached the small, somewhat globular bodies or ovules. This cavity

Fig. 480. Pistil of Thistle.
(After Thomé.)

within the ovule is usually called a cell by manuals, but a better
term is loculus, since the term ‘‘cell’’ is universally used to desig-
nate the unit of tissues. The thickened portion to which the ovules
are attached is the placenta.

The pistil of the May apple is a simple pistil and according to
the older views concerning the pistil, it is a carpel. The older
view was, that the carpel is a modified leaf. If one will imagine
a leaf folded and the margins joined so as to enclose a loculus and
then the outer part modified so as to form a style and stigma, the
conception of a carpel will be clear. An examination of the pistil
of oxalis will reveal five styles and stigmas, and one ovary with

MORPHOLOGY OF LEAVES AND FLOWERS 619

Fic. 481. Cross section of-the ovary of Gesneria showing one cell and two
parietal placentae.
(After Thomé.)

five loculi. This indicates that the pistil of oxalis consists of five
earpels whose ovaries have united to form one with five loculi.
This uniting may even extend to the styles and stigmas. A pistil
that is made up of more than one carpel is compound. )

Fic. 482. I. Cross section of the compound pistil of Snapdragon, showing the
two cells and the axillary placentae. II. Longitudinal section of an ovary
with a free central placenta.

; ‘ (After Thomé.)

Ovule.—The ovule is the most essential part of the pistil because
it is the forerunner of the seed. The ovule consists of a central
portion, the nucellus, which is enclosed by one or two jackets which
are called the integuments. The integuments do not entirely close
at the outer end of the nucellus and this small opening left is the
micropyle through which the pollen tube usually passes. In the
interior of the nucellus is a region which resembles a large cavity
since it contains no cell walls. This is the embryo sac. At about
the time the flower opens the embryo sac contains seven cells. The
two which have an important future history are the egg and en-
dosperm cells.

620 WEED FLORA OF IOWA

J

1
aa i}
ty

’ th
err \

Fic. 483. Diagrammatic representation of fertilization of an ovule. i, inner
coating of ovule; o, outer coating of ovule; p, pollen tube proceeding from
one of the pollen grains on the stigma; ec, the place where the two coats
of the ovule bend. (The kind of ovule here shown is inverted, its opening
m being at the bottom, and the stalk f adhering along one side of the
ovule.) a to e, embryo sac, full of protoplasm; a, so-called antipodal
cells of embryo sac; n, central nucleus of the embryo sac; e, nucleated
cells, one of which, the egg cell, receives the male nucleus of the pollen
tube; f, funiculus or stalk of ovule; m, micropyle or opening into the
ovule.

(After Luerssen.)

The egg is in the end of the sac nearest the micropyle, in the
most convenient position for the entering pollen tube. The en-
dosperm cell is near the center of the embryo sac. The embryo
sac is now mature and awaits the entrance of the pollen tube.

Fertilization—The pollen tube traverses the tissues of the
stigma and style and finds its way to the micropyle. It passes
through the micropyle, penetrates the tissues of the nucellus, and
pierces the membrane of the embryo sac. The two sperms, which
have had a rather long journey through the pollen tube, now enter
the embryo sac. One finds its way to the egg and soon fuses with
the egg nucleus. The other fuses with the nucleus of the endosperm

MORPHOLOGY OF LEAVES AND FLOWERS 621

Fig. 484 Fig. 485

Fic. 484. Embryo sac of Buttercup (Ranunculus multifidus). Near the center
is the large endosperm nucleus. The egg is the inner one of the three cells
at the upper end of the sac and lies between the inner ends of the two
synergids. The three antipodals are shown closely crowded at the lower
end of sac.

(After Coulter.)

Fig. 485. Fertilization in the Fleabane (Hrigeron) ; pt, pollen tube with two
densely staining bodies (x); a, male cell fusing with egg; b, male cell
fusing with endosperm nucleus.

(After Land.)

cell. This process in which the sperms or male nuclei fuse with
the nuclei of the egg and endosperm cell is fertilization, and both
fusions are designated as double fertilization.

THE DEVELOPMENT OF THE EMBRYO AND SEED.

When the fertilized ege germinates, a filament of cells, the
suspensor, is usually found. At the end of the suspensor the
embryo is developed which, when mature, is more or less sur-
rounded by nourishing endosperm which has resulted from the
erowth and division of the endosperm nuclei.

622

WEED FLORA OF IOWA

OR

FR

Gy?
St

:

;

se
ie SS

—

S25

Fic. 486. Development of the ovule and embryo of the Shepherd’s Purse

(Capsella). A, young ovule, showing origin of two integuments at base
of nucellus, n. 3B, outer integument growing beyond the inner, and the
ovule beginning to bend over; es, embryo sac. OC, diagram of a later
stage with mature embryo sac. D, development of the suspensor s. H,
early division of the terminal cell (embryo cell).. F, later stage, showing
the differentiation of an outer cell layer in the embryo, which is to be-
come the epidermis. G, the two cotyledons c¢ and the root region r now
clearly defined. H, lengthwise section of an ovule, showing the position
of an embryo in an embryo sac; em, embryo; s, suspensor; e, endosperm ;
di, inner integument; oi, outer integument; m, micropyle.
(A, B. C, adapted after Campbell. Ginn & Co.)

MORPHOLOGY OF LEAVES AND, FLOWERS {628

The two groups of higher seed plants, or Angiosperms, differ
widely in the structure of the embryo. In the group including the
grasses, rushes, sedges and such plants as wild onion (Allium
canadense) the globular embryo soon develops into an axis with
the root tip at one end and one cotyledon at the other. The stem
-tip arises from the side of the axis as a lateral member. This
group of: plans 2 is designated as Monocotyledons (one cotyledon).

Fig. 487 I Fig. 487 IT Fig. 488

Fic. 487. I. Fruit of Squaw-weed (Senecio). II. Fruit of Dandelion. Hach
is crowned with pappus which aids in distribution.
(After Thomé.)

Fic. 488. The fruit of the Winter Cherry (Physalis) with a portion of the
inflated Ses removed to show the enclosed berry.’
(After Thomé.)

)

In the other group, to which a large number of the weeds be-
long, the axis of the embryo develops a root tip at one end, a stem
tip at the other, and a pair of cotyledons, one on each side of the
stem tip. Since two is the prevailing number of cotyledons, the
term Dicotyledons is applied to this group. :

Fig. 489 i Fig. 490
Fic. 489. I. Fruit (pod) of Plantain with upper portion of pod breaking
and falling off to allow seeds to escape. II. Pod of Poppy opening by
a lid. :
, (After Thomé.)
Fie, 490. Fruit ae Mallow which separates into as many oné-seeded éarpels
as there are styles. Saas en aela
(After Thomé.)

624 WEED FLORA OF IOWA

Sced.—The seed is the matured ovule. It contains the young
plant or embryo which is the essential part of the seed since it is
through the later development of this young plant that new in-
dividuals are produced. Accompanying this maturing of the ovule,
various other changes take place which give distinguishing features
to different seeds. Frequently the endosperm grows so extensively
as to absorb and replace the cells of the nucellus and thus comes
to occupy all the space within the coats of the integuments, as in
the morning-glory, onion, etc. The embryo may remain compara-
tively small as in the morning-glory or onion, or it may in turn
absorb and replace all the cells of the endosperm and so come to
occupy the space within the integuments, as in the bean and clover.
Sometimes some of the nucellus and endosperm remain. The in-
teguments also undergo various changes during the formation of
the seed, often becoming hard or papery or provided with hairs,
hooks or spines, er becoming smooth or pitted.

Fig. 491 I Fig. 491 II

Fic. 491. I. Immature pistils of Geranium. II. Mature pistil and carpels
with their long styles are separating from the elongated axis.
: (After Thomé.) :

Fic. 492. Burry fruit of Jamestown or Jimson Weed (Datura) showing method
of dehiscing.
(After Thomé.)

Fruit.—A fruit is a ripened ovary alone or a ripened ovary plus
closely related parts such as calyx, involucre, and receptacle. In
the beggar-ticks (Bidens) the ovary becomes tough and invests the

MORPHOLOGY OF LEAVES AND FLOWERS 625

seed, while the awns which represent the calyx become barbed and
aid in distribution. In the buttercups the ovary invests the seed
while the style forms a hook. The involucre in the clotbur and
ragweed remains around the pistils and becomes more or less spiny.
In the nightshade (Solanum nigrum) the ovary becomés fleshy and
the fruit is called a berry.

40

CHAPTER V.

SCATTERING OF WEEDS

ADA HAYDEN

CHAPTER V.

SCATTERING OF WEEDS.

There is much to be observed as to how particular plants spread
from one location to another, but from the hosts of observations
that have been made the following means are recognized as agents
of conveyance to the disseminules of plants to suitable habitats.

Physical forces:

Wind
Water
Snow and wind
Animals:
Man, furred animals and birds
Mechanical adaptations:
Explosive devices
Hygroscopic movement
Burial

In comparing the amount of seed produced by a plant with the

number of plants maturing from that seed, it is evident that rela-

tively few plants reach locations favorable to existence. Wind
transported fruits may be recognized by their appendages in the

form of wings, comas of hair and bristly parachutes. Water
carried fruits are characterized by lightness, inflated coverings and
corky buoys. Seeds disseminated by animals are characterized by
hooked and clawed appendages or spines which become attached to
pelts or fabrics or have succulent portions which are edible. Scat-
tering by mechanical devices is illustrated by the forcibly splitting
pod, the twisted pod, the spearlike fruited grasses whose twisted
awns aid in entering the earth and the cleistogamous flowered plant
which buries its seeds in the earth.

Birds destroy large quantities of weed seeds. Mr. H. W. Hen-
shaw™ states that a ring-necked pheasant’s crop from Washington
contained 8,000 seeds of chickweed and a dandelion head. Birds
of the sparrow family, according to the same authority, feed largely
on the seeds of weeds. The tree sparrow consumes one-fourth ounce
of weed seeds per day. The tree sparrows on this basis annually
consume 875 tons of weed seeds in Iowa. These birds save the
farmers of the United States on this basis $89,260,000 annually.

*Henry W. Henshaw. Fifty Common Birds of the Farm and Orchard. Farm-
ers’ Bull. U. S. Dept. Agr. No. 5138.

630 WEED FLORA OF IOWA

Fig. 493A Fig. 493B Fig. 4930

Fie. 493. A. Seed of common Field Sorrel (Ozalis corniculata) with two cap-
sules from which the seeds are shot out. B and C. Common Dock (Rumez
crispus). Fruit scattered by the water. The wings surrounding the fruit and
tubercle make the fruit admirably adapted to floating on the water. Sec-
tion of the fruit showing wings and tubercle shown in C.

(Drawings by Ada Hayden.)

Parts of the fruit which serve as disseminating mechanisms.—
The stimulus of fertilization not only gives rise to the development
of a seed but causes parts of the seed or seed-case to develop in
many instances into a special contrivance for its dissemination. A
fruit, botanically speaking, is a ripened ovary, including any
closely attached parts, for example: the milkweed pod filled with
seeds bearing tufts of hairs; the dandelion fruit with its parachute-
like pappus.

Parts which serve as dissemination mechanisms:

Ovary wall.

a. Fleshy, often ‘attractively colored—cherry, horse
nettle, black nightshade.

b. Bursting—touch-me-not.

e. Inflated—sedge.

d. Corky tubercles—dock.

e. Winged—maple.

a. Capillary hairs—dandelion.
b. Spined—buffalo bur.

SCATTERING OF WEEDS

Fig. 494B

Fic. 494. Scattering of seed by wind. A. The Iowa Tumble Weed (Amaranthus
graecizans).

The weeds piled up against the fence; the Russian Thistle and
other weeds are scattered in a simi

lar way. B. Achene of Red-seeded
Dandelion. hates

(A, after Bergen’s Botany—Ginn & Co. ; B, drawing by Ada Hayden.)

Seed coat or its appendages.
a. Coma of hairs—milkweed.
b. “Mucilaginous—peppergrass.
e. Contractile seed coat—oxalis.
Receptacle.
a. Eleshy—rose.
Bracts—basswood.
Involucre.

a. Spiny—burdock, cocklebur.

- 631

632 WEED FLORA OF IOWA

The dissemination of weeds is not unlike that of other plants.
Weeds are’ commonly recognized as plants out of place, plants
which are detrimental to the growth of crops or otherwise in-
jurious. While ash or maple seeds are not usually placed in this
category ; if, in their seedling stage they monopolize a piece of soil,
for example a lawn newly planted with grass, absorbing the nutri-
ment and crowding the plants desired in this location, these in-
vaders have earned for themselves the title ‘‘weed.’’ The epithet

Fig. 495A Fig. 495B

Fic. 495. Seeds and fruit scattered by the wind. A. Basswood (Tilia ameri-
cana), a light bract to which is attached a stalk bearing the fruits. B.
Milkweed (Asclepias syriaca) pod and seeds.

(Drawings by Ada Hayden.)

‘“weed’’ brings to mind the obnoxious characters of the plants so
designated, yet weeds have just as respectable lineage as the palm,
olive, lily or laurel, and in their systematic relationships they
show by their structure that they are members of the first families
of the plant kingdom. Thus the notable rose family, which serves
the world with the apple, the plum, the cherry, the quince, the
peach and the pear, claims among its numbers the aggressive little
cinquefoil (Potentilla fruticosa), an invader of pastures and tilled
lands, the thorny prairie rose (Rosa pratincola) and the prickly
black raspberry (Rubus occidentalis), which without invitation en-
trench themselves upon the territory and contend with the agri-
culturist as to what shall occupy the soil.. Families such as the

SCATTHRING OF WEEDS 633

goosefoot (Chenopodiaceae) and the buckwheat (Polygonaceae)
are recognized as cohorts of marauders thronging the highways,
forging into fields, contesting with crops and contributing little
beauty and few representatives of economic value. The great cos-
mopolitan sunflower family (Composttae) contributes numerous
species of economic reputation as well as a goodly number of widely
recognized but combated species.

A large number of plants may be identified with their families
by their type of fruit structure only. Families which have little
variation in fruit structure have few agents of dissemination, while

families with considerable variation have usually several agents,
as in the sunflower family in which the calyx is represented by
bristles forming a parachute in the dandelion, lettuce or the

Fig. 496A. Fig. 496B

Fig. 496. Fruit scattered by the wind and animals. A. To the right
scattered by the wind: a, achene of Goldenrod (Solidago rigida) ; b, Blue
Flowered Lettuce (Lactuca floridana), the bristly hairs called the pappus.
To the left scattered by animals: a, an achene, commonly called a seed, of
Bootjack or Beggar-ticks (Bidens frondosa); b, Spanish Needle (Bidens
bipinnata).

B. Anemone (Anemone cylindrica).
(Drawings by Charlotte M. King, Ia. Agr. Exp. Sta.)

Canada thistle, or terminating in teeth as in Bidens or becoming
a spiny involucre as in the cocklebur and the burdock. Some
representatives of this family, for example the ragweed, have no
special means of transportation and the seeds fall in great quan-
tities near the mother plant where they germinate in large num-
bers if not distributed by wind-driven snow or by chance inclusion
with agricultural seeds. The seeds of the milkweed family

634 WEED FLORA ‘OF IOWA

ELS

o

Ke

Fig. 497A Fig. 497B

Fic. 497. Seeds and fruits scattered by the wind. A. Seeds of Catalpa (Catalpa
speciosa) with winged appendages. B. Key fruits of Soft Maple (Acer
saccharinum) are carried by the wind and in falling drop into the mud
or soft grass of the lawn.

(Drawings by Ada Hayden.)

(Asclepiadaceae) are provided with tufts of hair which serve to
float the seeds in the air as they escape from the pods. The oxalis
family (Oxalidaceae) have seeds whose outer seed coat separates
from the seeds shooting them from the bursting pods. The gera-
nium family (Geraniaceae) have contractile pods which shoot
the seeds several feet from the plants. The mustard family
(Cruciferae) have pods which burst but do not scatter the seeds
far. Many species of this group have seeds with mucilaginous
coats which, when in contact with damp surfaces, adhere to them.
Peppergrass is a well known example. This family has also some

SCATTERING OF WEEDS 635

Fig. 498A Fig. 498B Fig. 498C

Fic. 498. Weeds scattered by animals. A. Buffalo Bur (Solanum rostratum).
B. Pitchforks (Bidens frondosa), the downwardly barbed points admirably
suited for animal dissemination. C. .Carrot (Daucus carota).

(Drawings by Ada Hayden.)

Fig. 499A Fig. 499B Fig. 499C

Fic. 499. A. Cow with attached Burdock. B. Burdock enlarged. C. Com-
frey (Cynoglossum) enlarged.
(A, after Bailey, Macmillan & Co.; B, after Dewey, U. S. Dept. Agr.)

636 WEED FLORA OF IOWA

Fig. 500A Fig. 500B

Fic. 500. A. Weed seeds eaten by birds. a. Wild buckwheat (Polygonum con-
volvulus); b and d, Amaranth or Pigweed; ec, Chickweed; e, Spotted
Spurge; f, Ragweed; g, Foxtail; h, Dandelion.

B. Seeds of sedges carried by water.
(A, after Dewey, U. S. Dept. of Agr.; B, drawing by Ada Hayden.)

tumble weeds among which are several mustards like tumbling
mustard. The seeds of the sedge family (Cyperaceae) are com-
monly surrounded by inflated sacs or bear tubercles which enable
them to be carried by water. Grasses (Gramineae) show consider-
able variation in means of dissemination. Some grasses, for ex-
ample Stipa, have sharp fruits with twisted awns a prominent
factor. While dissemination is a prominent factor in the distribu-
tion of plants, the factor of adaptation to habitat is no less im-
portant for if a plant cannot adapt itself to the conditions in the
habitat where the seed falls the transportation is of no avail so far
as its development is concerned. Canada thistle produces some
seed in northern Iowa, where habitat conditions are more favorable
than. in southern Iowa.

SCATTERING OF WEEDS 637

Fig. 501. Birds scatter the seeds of the Wild Black Cherry (Prunus serotina).
1, flowering branch; 2, fruit; 3, fruiting branch; 4, cross section of fruit;
5, flower; 6, branch with buds.
(After Cheney in Green’s Forestry of Minn.)

From an ecological point of view weeds are plants which adapt
themselyes readily to ordinary agricultural conditions and since
most crops are grown under mesophytic conditions, most weeds
are mesophytes which adapt themselves to definite habitat con-
ditions such as cultivated field or uncultivated field and are readily
transferred with agricultural seeds, hence the association of certain
weeds exclusively with certain crops, for example, among the com-
mon clover field weeds are buckhorn, wild carrot and plantain.
These are not found in corn fields where cocklebur, horse nettle,
morning-glory and sandbur flourish. Many of the most obnoxious

638 WEED FLORA OF IOWA

Fig. 501A I : Fig. 501A IL

Fig. 501-A. I. Chicadee carrying fruit. II. Berries of Horse Nettle; carried
by birds.

Fic. 502. Mixture of weed seeds commonly found in low grade Alsike Clover
seed: a, Alsike Clover; b, White Clover; c, Red Clover; d, Yellow Trefoil;
e, Canada Thistle; f, Dock; g, Sorrel; h, Buckhorn; i, Rat Tail Plantain ;
k, Lamb’s Quarters; 1, Shepherd’s Purse; m, Mayweed; n, Scentless
Camomile; 0, White Campion; p, Night-flowering Catchfly ; q, Ox-eye Daisy;
r, Small-fruited False Flax; s, Cinquefoil; t, two kinds of Peppergrass;
u, Catnip; v, Timothy; x, Chickweed; y, Canada Blue Grass; z, Clover
Dodder; 1, Mouse Har; 2, Knotgrass; 3, Tumbling Amaranth; 4, Rough
Amaranth; 5, Heal-all; 6, Lady’s Thumb (enlarged).

(Hillman, U. S. Dept. Agr.)

SCATTERING OF WEEDS 639°

Ree

iis

aE

Fic. 503. Seeds of Poas with impurities. 1, Kentucky Blue Grass rubbed and
unrubbed; 2, Wood Meadow Grass (Poa nemoralis) ; 3, Ergot, a fungus;
4, Texas Blue Grass (P. arachnifera); 5, Canadian Blue Grass (Poa
compressa) ; 6, Rough Stalked Meadow Grass (Poa trivialis) ; 7, Silky Bent
Grass (Apera spica-venti) ; 8, Wood Hair Grass (Deschampsia flexuosa) ;
9, spine of Canada Thistle; 10, Canada Thistle; 11, caryopsis of Stink
Grass (Hragrostis major).

(U. S. Dept. Agr.)

640 WEED FLORA OF IOWA

weeds have not prominent dissemination mechanisms but are trans-
ferred with agricultural seeds, as carrot, buckhorn, dodder, sheep
sorrel, yellow trefoil, quack grass and pigeon grass. The separation
of impure seed from agricultural seed necessitates the recognition
by their morphological characters of obnoxious seeds.

An economic consideration of dissemination of weed seeds and
their control involves (1) familiarity with the morphology of the
fruit and seed; (2) the limitation of the habitat in which the weed
is able to thrive; (3) recognition of the avenues and agents of dis-
tribution.

CHAPTER VI.

ROOTS AND ROOT-STOCKS OF
WEEDS.

_ J. Cc. CUNNINGHAM

4t

CHAPTER VI.

ROOTS AND ROOT-STOCKS.

The study of root systems is accompanied with more or less dif-
ficulty and expense, and this, no doubt, accounts for the small
amount of work done along this line.

Two methods have been employed to obtain the complete root
system of growing plants. That used by Ten Eyck is perhaps the
most satisfactory, although tedious and expensive. It consists of
excavating about a plant and enclosing the whole mass of earth
containing the roots in a cage of wire netting. Steel rods are
thrust through the cage horizontally to prevent the roots from
breaking. The soil is then carefully washed away leaving the roots
very nearly in their natural position.

The other method, employed by a Russian investigator, Rot-
minstror, has given quite satisfactory results. The plants are
grown in soil made up of top- and subsoil. This is placed, the sub-
soil below and the topsoil above, in boxes 1 in. wide, 20 to 40 in.
deep and 20 to 40 in. long. These boxes are placed in the ground
level with the surface. The plants are then grown in these boxes
and removed when desired, the soil carefully washed away and
the entire plant transferred to paper.

Fic. 504. Root-stocks or rhizomes of Quack Grass (Agropyron repens). These
root-stocks are sometimes more than four feet long.
(Photographed by Stevens.)

644 WEED FLORA OF IOWA

The pictures shown here are of plant roots obtained by the
first method, the wire cages being omitted.

The roots of weedy plants vary widely in form, structure, and
in longevity. Their function is three- and sometimes fourfold:
First, to absorb water and dissolved mineral matter; second, to
anchor the plant in the soil; third, to act as a storehouse for re-
serve food, and fourth, may serve to propagate the plant.

Fic. 505. Roots of White Sweet Clover (Melilotus alba). Plants with several
strong branching roots.
(Photographed by Stevens.)

ROOT FORMS.

Root forms may be divided into four general types: First, the
primary; in this case a single, usually enlarged central root is de-
veloped. From it grow the smaller lateral roots. The burdock
(Arctium lappa), is of this class.. Second, multiple primary,
in which the embryonic root almost immediately breaks up into

ROOTS AND ROOT-STOCKS OF WEEDS 645

many usually enlarged and fleshy roots. Sweet clover (Melilotus
_ alba), Fig. 505, offers a good example of this type. Third, tuberous
or those that develop an enlarged portion at the end of a some-
what smaller one. Fourth, fibrous in which a mass of small roots
develop usually just below the stem as in most of the grasses and in
the plantains.

Besides the forms already mentioned we find various types of
aerial roots, or those that develop on the plant above ground. The
aerial roots of the ivy become finger-like and cling to objects to
assist the plant in climbing; those of the mistletoe and the dodder
become parasitic by pushing their aerial roots into the tissues of
the host plant and drawing nourishment from it.

In performing the four functions mentioned above the roots of a
single plant may occupy considerable area. Dr. Pammel has pre-
pared the following table showing the depth and spread of the
root system of a number of our noxious weeds.

Weed x Depth Spread
TIDE) OVO GL ONY eset BY Me LF 9 oral Ml a lg cn 2— 8 in. 24 sq. in.
BEST eairaety ea he a a a a 3 ll a Oe e113 = D382 ee
ATA VG) Teesea ey (eee PS oh SRS em ie ie @ © LO eases
TD VGIONNS SOVEATTA ROS) se eee HF 30). Res
IB ES Cae 1 OK Sie et te ee eee EWS RY Lie Sea a ih AQ swateay
ID) OP ete Te intetes heen aie ee ee aye Sout a ewe Ba Ae Sib ass
SINT Gre Ten ea hates eT Be Sa a Re ( & 20. Sees
GOLA SWC ee a ares i Te AN i iteay Oc eae
ANY ATT vehi pec ae SA a ee Da 4 ™ 36k sane
Canadiantletiweer sao a a te as i= 7 GeO
Riel Gibinistles 2a. sa) eas tee eae See ee Se Ey (heienwan: <<
TB GD EO XOX) fete oe eee ae wc ets Ss ee oe ee 40 “ LS re Aires
iBlackeniehtshad e: 2s eee ea eee l= 4 isto Wives) dives
Pennsylvania smartweed ____-_________________ Ik @ © alae fon
aTEN Give Ste Gl URTUN oe oe ee oe eae eS Ike ay QO in Sao
BVeHOWeOXAITS co. .2 | Sae ee er e eete 1a DS DA Recs
2 TICiypeletbUCen soo See" ie NS a Pale ee 4- 23% ear: Spee
COREG IG) ON es 3 see Pe en or San eee 4-10 “ BA Or oe
Girecietarne weed: (22a oe ea Li 48 in. long
ROUT WRIST OMVC OU a ae ee fellas & 144 sq. ft.
PETOT SG Ween yee es os 22 2 2 ST as oe Wale © 144 sq. in.
Mumallewieedier. eee ee es ok ATs hee B= © GO =
STV TOA VEC Mie oe 8! ae or Be ge GOS:
SpaMismdaseen a. 252. oo. 2 6 ee Oe ge Hee i AD somal it

The amount of reserve food stored within weed roots depends
to a considerable extent upon the length of time they continue to
live.

646 WEED FLORA OF IOWA

Fic. 506. Roots of Common Milkweed (Asclepias syriaca). These roots are
sometimes more than 14 feet long. Buds are numerously produced on the
root. More than 100 were found on the roots of this plant.

(Photographed by Colburn.)

ROOTS AND ROOT-STOCKS OF WEEDS 647

Roots may be classified according to their length of hfe, and this
is, perhaps, the most practical knowledge to possess concerning
weeds. Without this knowledge no intelligent or successful method
of eradication can be adopted.

First we have the annuals or those which complete their growth
and mature their seed in one year. These plants produce an
enormous amount of seed, sometimes as high as 50,000 to a single
plant. The root system is simple, although it may extend to a con-
siderable distance horizontally. Such plants are easily destroyed
by cultivation unless they root from the joint as in the case of the
erab grass (Digitaria sanguinalis).

Fic. 507. Roots of Curled Dock (Rumex crispus).
(Photographed by Stevens.)

Second are the winter annuals. These plants may begin their
growth in the spring, in which case they become annuals. Many
of the seeds, however, germinate in the fall and throw up a rosette

648 WEED FLORA OF IOWA

of leaves and thus pass the winter stage. In the spring stems
are thrown up from these leaves and seed is produced. Our com-
mon shepherd’s purse (Capsella bursa-pastoris) is an example.

The third class is the biennials or those which expend their energy
the first season in forming a root system, usually fleshy, and the
second season in maturing seed. We have numerous examples
among the garden crops, such as the beet, turnip, carrot, etc., while
among the weedy plants we have the burdock (Arctium lappa),
the sweet clover, figure 505, the wild parsnip and others. LE
these plants are prevented from forming seed the second year they
perish.

Fic. 508. Roots of Buckhorn (Plantago lanceolata). This perennial weed is
easily destroyed by cultivation.
(Photographed by Colburn.)

In the fourth class belong the perennials which live year after
year and for this reason become our most noxious weeds. When
the roots once become well established it is very difficult to eradicate
them, as is shown by the lawns, fields and pastures which are in-
fested with such weeds as dandelions, quack grass, Canada thistle,

ROOTS AND ROOT-STOCKS OF WEEDS 649

Fig. 509. Fibrous roots of Buckhorn,
(Photographed by Gardner.)

docks and wild morning-glory. These plants do not, as a rule,
produce large quantities of seed but depend upon the roots or
stems as a means of propagation. Thus if a field infested with
quack grass or morning-glory is plowed or disked the roots or
rhizomes are broken up and each piece may produce a new plant.

Some roots which do not spread extensively through the soil but
form new plants from offshoots from the crown, such as the docks
and wild gourds, form heavier reots from year to year for the fol-
lowing reason: The root growth is most active at the apex of the
main roots. This resumption of growth starves many of the older
roots, as we find few lateral on these older portions, and it thus
extends the root system.

In the annuals there is little need for a large amount of reserve
food within the roots for the elaborated food is used up largely as
it is manufactured. The life of the plant ceases when seed is
produced. In the biennials, however, large quantities of reserve

650 WEED FLORA OF IOWA

Wie. 510. Biennial root of Young Bull Thistle (Cirsium lanceolatum) after one
year’s growth.
(Photographed by Charlotte M. King.)

food are stored in the roots. The same is true of the perennials
although to a less marked degree than of the biennials.

By studying the root system in the late fall we may determine
roughly whether the weed is an annual, a biennial or a perennial.
That is to say, dead small fibrous or primary roots and seed produc-
tion indicate an annual; large fleshy roots and no seed production
a biennial; reserve food within the roots beside seed production a
perennial.

PROPAGATION OF WEEDS BY ROOTS AND STEMS.

Prof. Hitchcock says that weeds may be propagated by seed and
buds or by vegetative sprouts. The layman is inclined to eall all
parts of the plant below ground root. It may be, however, a stem
called a root-stock or rhizome. Microscopical examination is often
necessary to determine which is root and which is stem.

ROOTS AND ROOT-STOCKS OF WEEDS 651

Rye, 5iit. Underground rhizomes of common Morning-glory (Convolvulus
sepium).
(Photographed by Stevens.)

Roots.

Adventitious buds are produced at indefinite points along the
roots and from them stems and plants develop. A number of our
noxious weeds are propagated by these running or creeping roots,
such as: milkweed (Asclepias cornuti), bindweed (Convolvulus
arvensis), sheep sorrel (Rumex acetosella), Indian hemp (Apocy-
num cannabinum), perennial ragweed (Ambrosia ee
pasture thistle (Cirsium undulatum).

The weeds mentioned above are comparatively shallow raoted!
A few weeds are propagated by buds which come from deep vertical
roots. Among them we find the following: horse nettle (Solanum
carolinense), ground cherry Re ssis sp.), Canada thistle (Cirsium
arvense ).

UNDERGROUND STEMS oR RHIZOMES.

These underground stems are usually found at a short distance
beneath the surface. Along these stems are found nodes with leaf
seales at definite intervals. From these nodes roots develop which
penetrate the soil and leafy stems which develop above ground.
Some of the weeds so propagated are as follows: quack grass

652 WEED FLORA OF IOWA

Fic. 512. Roots of Sour Dock (Rumezx crispus).
(Photographed by Stevens.)

(Agropyron repens), morning-glory (Convolvulus sepiwm), smart-
weed (Polygonum muhlenbergw), poison ivy (Rhus toxicoden-
dron), nettle (Urtica gracilis), wild rose (Rosa arkansana).

Fic. 513. Rhizome of Solomon’s Seal; a, leaf bud; b, old stem; ec, d, old stem
scars.
(After Thomé.)

ROOTS AND ROOT-STOCKS OF WEEDS 653

Fic. 514. European Morning-glory or Bindweed (Convolvulus arvensis). In gar-
dens and fields.
(After Clark and Fletcher.) [

654 WEED FLORA OF IOWA

CROWNS oR SHORT OFFSHOOTS.

A long list of weeds produce heavy crowns near the surface of
the soil. Stems spring from these crowns year after year. Parts
of the crown may become separated from the parent plant and
thus form an independent plant. Among the weeds so propagated
we find the dandelion (Taraxacum officinale), white vervain (Ver-
bena urticaefolia), plantain (Plantago lanceolata), catnip (Nepeta
cataria), curled dock (Rumex crispus), smooth dock (Rumex
altissimus), rib grass (Plantago lanceolata), ox-eye daisy (Chrysan-
themum leucanthemum).

CHAPTER VII.

NUMBER AND KINDS OF WEEDS
ON DIFFERENT SOILS.

CHAPTER VII.

NUMBER AND KINDS OF WEEDS IN DIFFERENT FIELDS.

During the season of 1912 Mr. Robert H. Birlingmair counted
the weeds appearing on various fields under different conditions,
for this purpose four feet each way being measured off and the
different weeds noted. The results were as follows:

FIELD 1.*
Weed Date
Mar. 29) Apr.6 | Apr.138] Apr. 20| Apr. 27| May 4
Peppergrass** _________ 24 14 8 0 1 Sao ene als
Dandelion ______--_____ 6 oe | Neate te el ee nN a ee ae a Se ah
Tall fivefinger ________ 3 1 Ds (i vere ee PEMA at 1
Smimallrae wee oar ara es Sa Se 1 31 10
IBWey STASS. ws ses DUP ara: eee pile 9, ete n ee 3 24
Bracted vervain —_____ UO) 95 oad eek os aS eee ee DR ee SG ae
IMUMSC ATG 250 Lees TU ier ce bei Mates Ns pe ee i at kee ane ee |p e a
Daisy fleabane ~---____|__-_____ 8 TDi ee SIRES Soh | eee Ee a hieles
TR TENG EEK Ups Sse S| ep LR es | DEAD ASS aN aan eS A taee
Spotted spurge ____- sae AR ES a be PN 282 460
AFOTESE VCC les ee ae i a ee eh 4 6
Pennsylvania
SSTTEANTS EAVVA@ Chee eee cremmeta tes [eee ee ee ea ae 4 1248
GROWN CERT ye Behe oe es ee 2 2;
Greenmtorc alee sal Soy Pee eae roma eo eee 84
TS SS Pe PE HNTB tc Heat 2

*On corn land that was in blue grass sod last year.
** A winter annual.
FIELD 2.*

Weed : Date

Mar. 2 Apr.6 | Apr. 13} Apr. 20 | Apr. 27 | May 4

VE SUNN ONY THO UM Ey TE | 10

TYPES G? “TRUST Oe Wa EE Ie | Un

Horseweed** _____---_- 1438 (a5y ea | a ee il 34 72

<i) NY GXUEA YAS NE ee gO ee SS ec ER) aN AEF eit C0 ere ec el We Vir este

Plantae oe See Ss

Pennsylvania
STMMENTRUE CCles seen Sea 2 SUR parece iret SYN Hh | eo ered ee

*On timothy meadow.
** Winter annual.

42

658 WEED FLORA OF IOWA

FIELD 3.*
Weed Date
Mar. 9 Apr. 6 “Apr 13| Ape. 20| apr. 27| May 4
Small racweed 222222) 2 eae ite |) |: eee
Pennsylvania
Smartweed (i. 220 22 8) ee eee oy 2 ee il
Green: foxtail 222-223) Be a | eee ee shee

*On corn land that had been fall plowed. Field worked up and sowed to
small grain just before April 27.

FIELD 4.*

Weed Date

Mar. 9 Apr. 6 | Apr. 19) Apr. 20 | Apr. 27 | May 4

Smalilraciweedii22.. 24) s ees eee 10 3 8 of REE eee
aM DiSe GUAT ECTS 2. 22] 25 we aa eee ae | ee 1 3
Pennsylvania

Simariwieed 22 = a. aa. ee eee 21 78 99 77
Wellowetoxtail 22522.) a ee | 215

*On land sowed to winter wheat.

FIELD 5.*
Weed Date
Mar. 29) Apr.6 | Apr.18| Apr. 20 | Apr. 27 | May 4
Yellow foxtarl: ese Rees oo 2 a [Ae eee | 999
Green Lomt aid: oe ee Ce ee 718
Daisvatlieahnane 2] ae aa YP | Se ee cs ee |
Bracted vervain 22a Pewee eee ea Ohh pal ese 2 YDS ee
‘Peppergrass) 2-2 ee paar ie es ie Bo eae
YU TS Se a | | 8 | Sa 4 V5] SEE See
Pennsylvania
SIMIAT EWE ee cck a Ean | a 40\- <5|eeandie
Spul'@e isso ssee see ee ee eS |e ee 47

*On old corn land. Stalks harrowed down just previous to Aprii 20.

NUMBER AND KINDS OF WEEDS ON DIFFERENT SOILS 659

Weed

Small ragweed —_-_____-
Yellow foxtail ~_--____
Green toxtail 22252.
Lamb’s quarters______-
Pennsylvania
SIMantweeds222-22—. =
JEU AS Se ee
Dooryard knotweed ---
Horseweed ------------
S DUES Cpe eee ae ears Se
Hedge mustard _____-__

*On fall plowed oats stubble.

Weed

Dandehiong22s] ae. =
MeroniGay 222-4 a
Lamb’s quarters —___--
Small ragweed_______-
Yellow foxtail 2-2:
Shepherd’s purse _____-
or peppergrass —_____
iBlueteriss
Hoary vervain —-______
Pennsylvania
smartweed —-_-______
Lady’s sorrel] =-.---.=-

FIELD 6.*
Date

Mar. 29| Apr.6 | Apr. 13 | Apr. 20 | Apr. 27 | May 4
A DS NN SIR oe Ee 1 30 eee x

SO Ta STR eB ES eee cS | NA 475

ey LL a Redhead SM me eS 40)

face one Cen ee rena i ee 3
WB poe eats |e Bee 11 54 VED eve RE eia yee ee
Fo ge ana lea As oS rs Mi bg 8 PE ote ot a pe

Sep eh a FS es aa | eRe aes: RNS Se ee 3

i ee Yl Oa he etv en WS Ct 0 Geog PA a se a 3

Ro | C Rn a ae Ee RE H POa EDe BaE 39

Re eee (aes ae Shee | ows ee eA Aa at eit aeee 71

FIELD 7.*
Date

Mar. 29} Apr.6 | Apr. 13 | Apr. 20| Apr. 27| May 4
5 AML ged eee ae es ec Sesto a
Poste, Oak RM a eel edge ok ae cea ee
ccatt einer ey ease eS eh ae eee 1 cae ie Meee a AOS 5 tale
2S er ea A Se 9 6 Mlle AAD eral |

Pyrat cate 82 8S Sd i Sense O(a ee 16
75 5 LA Ratti ers eee Pa cored ferns
aL +4 117 0 aul cate, ead es eee eae 8 aa
2 a 7 a [eva a a Ok
SE Ss ers atonal ga | es Pe |
or tel eee ilgane st ee ae 1 ui Es 6 eas nn a
ER) Sls Be eS 0 nek Naa yal) Si a Sea ps |
+Marks

*On unplowed oats stubble. Field plowed previous to April 27.

winter annuals.

660 WEED FLORA OF IOWA

FIELD 8.*
Weed Date
Mar. 29} Apr.6 | Apr. 13 |r. 26 | Apr. 2 May 4
Small ragweed —--_----|_------- 33 ve 8: “|ste2 ne Eee
Mexican’ GropSeed 220s eee eas +437 +45 /|+4+16 |++18
Lamb Ssquacterss= =| aaa (ee 10 nee Ee
Morning elory (2252223 eae es | eee +44 446 /|447
Spurge. aes eee ee eee et to te ee 49° >| ee
Yellow foxtail .. £22 2 0|Se 28 22u)_ 2 ceo eee ee
Green: foxtall: 5a ae a eee 098) |e 1785
Pennsylvania
smartweed _~--------- 15 38 65 49° De See eee
Mustard) 222222 93° Niue S ee ee ee
‘Horseweed: ] 2 eeeeesases| 222 a/b 9 10 11
Secribner’s panic grass_|_-_-_--_|-----_-- +4 |. =-2-- |. eee
Tansy mustard —__--~-_|_-------|-------- Fae -Yanens emer fete SS |e
Ny Cteleay- Sesame 6 as 2 Sree | Se eee § _|-23 eae
Yellow dodke2222)). | |h eae ———E—E————ee +158
Large spottedtspurce..|22 = Se ee eee eee 129
Old: witchworasse: 2-2) 22 ee ee ee ee 2
Wild fourocloelk 22.222) ee ee 12
Selif-he ail eee | ee ee 2

*In sheltered place on the south side of the railroad grade. Weeds were
not all counted on April 27th, but there were hundreds of small ragweeds and
smartweeds, and probably more than a thousand green foxtail plants.

++Winter annual.

+Perennial.

These tables reveal some interesting facts. The first weeds to
appear in March were the winter annuals, like peppergrass and
shepherd’s purse, certain perennial weeds, and in one ease horse-
weed (Erigeron canadensis) in a timothy meadow. Two weeks
later smartweed (Polygonum) was abundant. Spurge (Huphor-
bia), an annual, was abundant in the latter part of April and
early May. Foxtails in some cases surpassed all other weeds in
abundance early in May. The smartweeds (Polygonum) and
spurges increased enormously. These weeds were entirely removed
from the plots. Fall plowing and clean cultivation certainly in-
dicate a smaller number of weeds.

Long, who measured off a square yard of ground in* Great
Britain, roughly grouping its plant life therein into species, found
on this square yard 1,050 seedlings or 5,082,000 per acre. There
were 654 buttercup seedlings, 107 of annual meadow grass, 60 of
dock, 26 of goosefoot, 25 of groundsel, 15 of shepherd’s purse, 14 of

*Trans. of Highland Agri. Soc. Scotland V. 28: 52.

NUMBER AND KINDS OF WEEDS ON DIFFERENT SOILS 661

Fic. 515. A weedy cornfield, mostly Foxtail and Smartweeds.
(Photographed by Colburn.)

annual sow thistle, and 10 of chickweed, besides 139 of other
species. He states that Korsmo’s investigation revealed the pres-
ence of an even larger number of seeds having the power of ger-
mination, the seeds per square yard to a depth of 9.8 inches being
as follows: Fallow field, 8,682 weed seeds (over 42,000,000 per
acre) ; field for spring grain bearing the same crop for four suc-
cessive years, 28,213 weed seeds (over 136,000,000 per acre) ; fallow
field, 1,474 weed seeds (over 7,000,000 per acre).

Mr. Long gives the following species of weeds found in Great
Britain within an area 100 feet square:

662

Fic. 516.

WEED FLORA OF IOWA

ChE we ay ay,
N WY "

SING 2
ny’ V ¢
gy.

S|

\V a i
Shepherd’s Purse, a common winter annual.
(After Vasey, U. S. Dept. Agr.)

NUMBER AND KINDS OF WEEDS ON DIFFERENT SOILS 663

Fig. 517. A cornfield from which Quack Grass was removed by hoeing and
cultivation. In adjacent check it formed a sod. The check was given the

ordinary methods of cultivation.

(Photographed by Colburn. )

*Convolvulus arvensis (Euro-
pean bindweed.)

*Polygonum convolvulus (Black
bindweed )

*Polygonum aviculare (Knot-
grass)

*Rumex sp. (Dock)

*Tussilago farfara ‘(Coltsfoot)

*Mentha arvensis (Pepper-
mint)

*Sinapis arvensis (Common
mustard )

*Sonchus arvensis (Field sow
thistle)

*Stellaria media (Chickweed)
Papaver sp. (Poppy)

*Ranunculus arvensis (Corn
crowfoot)

*Viola sp. (Violet)

Potentilla anserina (Silver
weed)

Aethusa cynapium (Fool’s
parsley) ;

Scandia pecten-veneris (Ven-
us’ comb)

Senecio vulgaris (Groundsel)
*Galium aparine (Cleavers)
Victa sativa (Vetch)

664 WEED FLORA OF IOWA

*Matricaria wmodora (Wild *Agrostis sp. (Bent grass)

chamomile) Agropyron repens (Quack
Plantago major (Common grass)

plantain) Poa annua (Low spear grass)
Lychnis alba (White cam- *Veronica sp. (Speedwell)

pion) , | Myosotis sp. (Forget-me-not)
“Euphorbia exigua (Spurge) Alchemilla arvensis (Parsley-
“Alopecurus agrestis (Foxtail piert)

erass)

Most of these species are troublesome weeds, and it may be added
that those marked with * were abundant.

For an Iowa cultivated field on June 2, 1903, the following
weeds were found in one square rod.

Name of weed. No. per sq. rod.
Smartweed (Polygonum pennsylvanicum) ........0..0.e ee eeeeee 40,324
Hedge mustard (Sisymbrium officinale)..............5++-+- to 3,060
Black beggar-ticks (Bidens frondosd)...............0ceceee cere 476
Prickly lettuce (Lactuca scariola var. integrata)..........+--- os 204
Pigweed \(Ohewepon1un .al 1m) sane yee eee ee 340
Horseweed (Hrigeron CANAdENSIS) .... sce eee e ween cere cece ceneee 7,412
Dandelion (Tarawacum Officinale) .......e cece reece eee eee eceeee 68
Moxtail (CS€t@rig) sce c2 cdiemacaies oe Satie olgae oda aier gees mee eine 136,000

WEEDS AND CONTINUOUS CROPPING.

Everyone has observed that continuous cropping increases the
number of weeds; not only is this true for many. parts of Iowa but
it is equally true for the older sections of the United States and of
Europe. A. D. Hall who reported on the crops grown in grain
land at Rothannstad* said:

After continuous cropping for forty-seven years uel weeds of all
descriptions occupy considerably more space after continuous crop-
ping than before. The relative proportion they bear to the grasses
and clover has increased from year to year. Such weeds as barnet,

hawkbit and black knapweed became abundant.

Mr. Long gives the following list of worst weeds made by four
expert Scotch agriculturists :

Arable Land.—Charlock, runch, chickweed, spurrey, docks,
thistle, groundsel, coltsfoot, day nettle, red-shank, annual meadow
grass, bulbous oat grass (pearl grass), couch grass, fine bent grass
or black couch, and wild oats.

*Jour. Roy Agr. Soc. 64:-88.

NUMBER AND KINDS OF WEEDS ON DIFFERENT SOILS 665

Fic. 518. Green Foxtail (Setaria viridis). Common in gardens and fields.
‘ (Photographed by Colburn.) '

Grass Land.—Buttercups, self-heal, docks, ragwort, daisy, thistles,
ribwort, plantain, creeping soft grass, common bent grass, York-
shire fog or woolly soft grass, moss.

There are, however, many other weeds which are given by him
which are serious pests to the agriculturist of that country. Of the
weeds of the arable land he lists buttercups, poppies, fumitory,
charlock (Brassica arvensis), runch (Raphanus raphamstrum) , shep-
herd’s purse, corn cockle, spurrey, silver weed, cleavers, thistle
(Canada thistle), sow thistle, coltsfoot, groundsel, bindweeds (Poly-
gonum convolvulus), (Convoluulus arvensis), dodder, buckhorn,
plantain, broom rape, corn or field mint, hemp and dead nettle,
smartweed, or red-shank (Plygonum persicaria), knotweed, docks,
goosefoot, quack grass, fine bent grass, pearl grass (Arrenatherum
avenaceum), slender foxtail (Alopecurus agrestis), wild oats and

666 WEED FLORA OF IOWA

Fic. 519. Needle Grass (Stipa spartea). In pastures.
(Photographed by Charlotte M. King.)

Fie. 520. Purple Cone Flower (Brauneria purpurea). In a prairie pasture.
(Photographed by Pammel.)

NUMBER AND KINDS OF WEEDS ON DIFFERENT SOILS 667

horsetail. Of grass land weeds there are listed (Colchicum autum-
nale), buttercups, leguminous weeds, gorse (Ulex) broom, rest har-
row (Ononts spinosa), dyer’s green weed (Gemsta tinctoria), wild
carrot, burdock, knapweed (Centaurea nigra), thistles (Cirsiwm
arvense, C. acaule, C. lanceolatum, C. palustris), cotton thistle
(Onopordum acanthium), daisy (Bellis perennis), ox-eye daisy, rag-
wort (Senecio jacobaea), plantains, yellow rattle, self-heal (Pru-
nella vulgaris), docks, sorrel (Rumex acetosa, R. acetosella), sting-
ing nettle (Urtica dioica) ; grasses: bent grass (Agrostis alba) tus-
sock grass (Aira caespitosa), Yorkshire fog (Holcus lanatus),
creeping soft grass (H. mollis), quaking grass (Briza media), bar-
ley grass (Hordeum pratense), and the bracken (Pieris aquilina),
horsetail, and mosses.

\

Fic. 521. Common Porcupine or Needle Grass (Stipa spartea). A weed native
to gravel soil, soon succumbs to cropping. a, single spikelet; b, fruit with
sharp pointed callus.

(Lamson-Scribner, U. S. Dept. Agr.)

CHAPTER VIII.

INJURIOUSNESS OF WEEDS

CHAPTER VIII.

INJURIOUSNESS OF WEEDS.

Weeds are injurious to man in the following ways:

1. They crowd out the growing crop.

2. They consume the moisture necessary for a crop.

3. They consume the mineral or other food elements essential
to a crop.

4, They pull down the crop.

5. They are injurious because the seeds are difficult to remove.

6. They are injurious because they harbor insects.

7. They are injurious because they harbor parasitic fungi.

8. They prevent the proper cultivation of the soil.

9. They may cause conditions which breed disease.

10. They may poison the soil.

11. They stop drains.

12. They poison animals and man.

1. WEEDS CROWD OUT GROWING CROPS.

When weeds are abundant they crowd out growing crops. Every
plant requires a certain amount of space to bring forth a bountiful
erop. Two plants cannot grow together in the same place; sooner
or later, one plant will crowd out the other. If the weed is a more
vigorous grower, like the greater ragweed, it will prevent the oat
plant from maturing a crop. It prevents the proper amount of
light coming to the plant, and so the food neecssary for a crop can-
not be made.

2. WEEDS CONSUME THE MOISTURE.

To produce a crop all weeds need moisture, which should go to a
more desirable crop. They transpire water just as cultivated plants
do. Long, in ‘‘Common Weeds of the Farm and Garden,’’ says:

29

Weeds also absorb from the soil and ‘‘transpire,’’ or pass off into
the atmosphere, large quantities of moisture which would be of
great service to the growing crop. For example, a maize plant has
been observed to transpire in the 16 weeks between May 22d and
September 4th as much as 36 times its own weight. A large oak

672 WEED FLORA OF IOWA

Fic. 522. Ragweeds (Ambrosia trifida) consume an enormous amount of mois-
ture.

INJURIOUSNESS OF WEEDS . 673

tree is also stated to transpire 10 to 20 gallons of water in a day;
while barley, beans, and clover were found to transpire, during
five months of their growth, over 200 times their dry weight of
water. Experiments conducted at the agricultural experiment sta-
tion of Cornell university showed that during the growth of a 60-
bushel crop of maize the plants pumped from the soil, and tran-
spired into the air through the leaves, upwards of 900 tons of
water. A 25-bushel crop of wheat similarly disposed of 500 tons of
water. Weeds also transpire, and if the ground be covered with
weeds it is certain that much of the moisture which would be of
value to the crop will be lost in the manner indicated. Weeds are
especially harmful in this way in a hot summer, and the loss is
most felt by the cultivated crop on light sandy soils.

3. WEEDS CONSUME MINERAL AND FOOD ELEMENTS.

A weed needs not only the carbon dioxide of the air to make
food, but the nitrogenous and mineral elements of the soil to make
plant food, all of which should go to the crop. Long gives the fol-
lowing in his book, ‘‘Common Weeds of the Farm and Garden’’:

Some analyses made at Konigsberg, and lately reported by Profes-
sor Stutzer and L. Seidler, show that the amounts of nitrogen, phos-
phorie acid, potash, and lime which are removed are deserving of
serious consideration. A number of weeds without their roots were
collected from oat fields, the soil of which was fairly heavy and
poor in humus. In the case of the Wild Radish or White Char-
lock the plants had already formed many seed-pods, but the other
weeds were in full bloom. The table following shows the percentage
of ingredients in the dry matter. These figures indicate in a gen-
eral way the amount of the chief plant foods required by weeds. The
nitrogren in the Persicaria nearly equaled 20 per cent, and that in
the Sow Thistle nearly 15 per cent of albuminoids in the dry mat-
ter. Phosphoric acid was chiefly taken up by Spurrey and Persi-
earia; potash by the Sow Thistle and Spurrey; and lime by Per-
sicaria, Yarrow, and Cornflower.

43

674 WEED FLORA OF IOWA

PERCENTAGE CONTENTS OF DRY MATTER.

1
]

f=) (oho)
e ee Zz ° E 34
= 2 © 2 iE za
GZ ce ou = nN io)
Sow thistle (Sonchus oler-
ACCUS) 0 MSE eR ai there ans eek 2.39 0.88 4.77 1.94 2.16 14.95
Cornflower (Centaurea cy-
CNUS) A Vda oe eich eee 2.30 0.78 1.94 3.13 1.07 8.12
Spurrey (Spergula arven-
SUS)! Sasa Oe Ress oe eee 2.36 1.08 4.21 1.52 1.91 10.12
Wild Radish (Raphanus
raphanistrum) .......... 1.85 0.78 1.30 1.81 0.71 5.22

Persicaria or red-shank

(Polygonum persicaria).'| 3.12 1.16 3.12 4.93 2.53 10.58
Yarrow (Achillea millefol-

AULT) ©. ctsisec ee ROOT ue 2.30 0.93 3.15 3.84 ali 9.61
Average of six weeds..... 2.38 0.93 3.08 2.86 1.59 9.76

4. WEEDS PULL DOWN THE CROPS.

Weeds like morning-glory, bindweed, wild buckwheat, and others,
pull down a cultivated plant and then prevent the formation of a
good erop.

5. WEEDS ARE INJURIOUS BECAUSE IT IS DIFFICULT TO RE-
MOVE THE SEEDS.

It is difficult in many cases to remove weed seeds from seed of
various kinds. Buckhorn can be removed with difficulty from
clover seed; peppergrass with difficulty from timothy seed; greater
ragweed from wheat; wild oats from oats; quack grass from brome
grass; cockle from wheat. These impurities often greatly reduce
the quality of the grain or seed.

6. WEEDS HARBOR INSECTS.

Long gives the following insects found on weeds:

Uf ZA ENGIN LAWS

Ez . .
i)

Fic. 523. Morning-glory pulls down the corn and other crops.
(After Vasey, U. S. Dept. of Agriculture. )

676 WEED FLORA OF IOWA

SS

Fic. 524. Impurities found in Red Clover: 1, Bull Thistle; 2, Canada Thistle;
3, Green Foxtail (Setaria viridis) ; 4, common Plantain (Plantago rugelit) ;
5, Peppergrass (also found in Timothy); 6, Chicory; 7, Pigeon Grass
(Setaria glauca) ; 8, Crabgrass (Digitaria sanguinalis) ; 9, Old Witch Grass ;
10, Timothy; 11, Wild Carrot; 12, Pigweed (Amaranthus retroflexus) ; 13,
Smartweed (Polygonum persicaria) ; 14, Lamb’s quarters; 15, Dropseed
Grass (Muhlenbergia).

(Drawings by Charlotte M. King.)

Weed “host.” Insect.

Turnip Flea Beetle or “Fly” (Phyl-

Charlock (Sinapis arvensis) and lotreta (Haltica) nemorum)
similar Crucifers Cabbage and Turnip Gall Weevil -
(Ceutorhynchus sutlcicollis)

Goosefoot (Chenopodium album)
Thistles (Cirsium sp)
Sow Thistle (Sonchus) . Mangold Fly (Pegomyia betae)
Dandelion (Taraxacum) and appar-
ently Docks (Rumez)

INJURIOUSNESS OF WEEDS 677

Charlock and other Crucifers Diamond-Back Moth (Plutella mac-
Prickly saltwort (Salsola kali) ulipennis)

Thistles, and the Cotton Thistle

(Onopordon Acanthium) } Celery Fly (Acidia heraclei)

Hops, Yorkshire Fog, Poa annua, aN

Daisy, Shepherd’s Purse, Spurrey, :
Buttercup, Cornflower, Sow This- + See Merete devas

tle, Black Bindweed (Polygonum
Convolvulus) and Plantain

Nightshades, Henbane, Hedge, cana Colorado Beetle (Doryphora decem-

tard, Thistles, Goosefoot, and lineata)

many other plants

Shepherd’s Purse, Winter Cress, | Cabbage Root Fly (Phorbia bras-
Hedge Mustard sicae)

Various Grasses } Frit Fly (Oscinis frit)

Docks, Goosefoot, and some ee

weeds Bean Aphis (Aphis rumicis)

Ghost or Otter Moth (Hepialus
Docks, Thistles, Burdock lupuli)

7. WEEDS ARE INJURIOUS BECAUSE THEY HARBOR PARA-
SITIC FUNGI.

' Long and Percival, in ‘‘Common Weeds of the Farm and Gar-
den,’’ have the following table of fungus diseases that affect va-
rious weeds:

Weed “host.” Disease.

Finger-and-toe of turnips (Plasmodio-
phora brassicae Wor.)
Peronospora parasitica De Bary

Charlock and other Crucifers

White Root-rot (Rosellinia necatria
Prill.)

Sclerotium Disease (Sclerotinia scleroti-
orum Mass.)

Many species

inum) sporium gramineum ESSE)

Shepherd’s Purse and other
Crucifers

White Rust of Cabbages (Cystopus can-
didus Lev.)

Many species a. Root-rot (Rhizoctonia violacea
Agrostis canina L., and other
grasses

Reed-mace Fungus (EHpichloe typhina

Wild Barley (Hordeum mur: u Blindness in Barley and Oats (Helmintho-
i
} Tul.)

678 WEED FLORA OF IOWA

Barberry { Rust of wheat (Puccinia graminis Pers.)
Aakers Gooseberry-leaf Cluster-cup (Puccinia
Sedges (Carex) \ pringsheimiana Kleb.)

Goosefoot t Peronospora effusa Rab., on spinach.

Docks, Sorrel, and many) Rosellinia radiciperda Mass. A white
others Root-rot in New Zealand.

\ Chrysanthemum Rust (Puccinia hieracii

Hawkweed (Hieracium) Mart.)

Groundsel, Ragwort, and) Pine Cluster-cups (Peridermium pini
other species of Senecio Waillr.)

Many wild grasses t Ergot of rye (Claviceps purpurea Tul.)

SOD :
(Sexes

QOS (Tee, -
) RS Ce

e Ets

WSs

an CD @

cea ) JOOS ss

aes KS
52000) )

(EE Ce

<A

Fic. 525. Leaf rust of Wild Barley (Puccinia rubigo-vera) also occurs on
wheat.
(Drawing by Charlotte M. King.)

These fungus diseases are particularly noticeable in a number
of plants of the mustard family. The Cystopus candidus common
upon cabbages in Europe is very common on a large number of
cruciferous plants, like mustard, peppergrass, charlock, ete. At
times it is very common upon the radish. A related fungus, downy
mildew. of the mustard (Peronospora parasitica) is common and
troublesome at times on some cultivated members of the mustard
family. It is particularly common upon peppergrass and shep-

INJURIOUSNESS OF WEEDS 679

Fic. 526. Rusts of cereals also occur on weedy grasses, like Squirreltail Grass,
Wild Oats, ete. Puccinia graminis: <A, “‘winter’ or teleutospore; t, ger-
minating, B, germ-tube (promyceliwm) with lateral sporidia sp. C,
epidermis of under surface of leaf of barberry showing crescent shaped
cells of stoma and the germinating sporidium sp at i penetrating the
epidermis. D, uredo spore germinating after being in water fourteen hours.
E, Puccinia rubigo-vera, the upper cell has germinated. C. D. HE, magnified
390 times, the other somewhat more. (After DeBary.) F, Puccinia gram-
inis, Pers.; both cells have germinated; a, a sporidium germinating, magni-
fied 600 times. (After Bolley.) G, Puccinia coronata Cda.; teleutospores
of rust on leaves of oats, magnified about 690 times. (After Bolley.)

680 WEED FLORA OF IOWA

R

f

@)
4 a

Fie. 527. Barley Blight (Helminthosporium gramineum) on Wild Barley. a
and b, hypha; ec, conidium.
(Drawing by Charlotte M. King.)

YW

herd’s purse. One of the very destructive diseases is the elub-root
of cabbage (Plasmodiophora brassicae) which is common upon eab-
bages in the eastern states, having now reached Illinois. This has
been found on «a large number of weeds of the mustard family,
like mustard and charlock. A list of these was given by Dr. B. D.
Halsted some years ago. Another most troublesome fungus dis-
ease is rust of wheat (Puccinia graminis) which is abundant upon
quack grass, red top and other grasses. This rust frequently
spreads upon these weeds and then to our cultivated cereals. Some
of the related rusts like Puccinia rubigo-vera are common upon the
leaves of squirrel-tail grass. A great many of the wild weedy .
erasses, like wild rye and quack grass, contain ergot (Claviceps
purpurea). This is responsible in most cases for the conveying
of this disease to cultivated cereals. We have a long list of root
diseases found upon various weeds, like the scab of potato (Oospora
scabies, Ozonium omnivora), ete. Certain species of Sclerotinia,
one of which occurs upon sunflower, are transmitted from these
weeds to cultivated plants.

INJURIOUSNESS OF WEEDS 681

Fic. 528. White Rust (Aibugo candida). 1. Inflorescence of Shepherd’s Purse
with fungus. 2. Mycelium with haustoria (h) x 390. 38. Conidiophores
and conidia (spores) in chains x 400. 4 and 5. Formation of zoospores in
conidia x 400. 6. Germinating zoospore. 7. Oogonium (0) and anther-
idium (a) attached, mycelium shown below. 8. Oospore with thick wall.
9. Germinating oospore forming a zoosporangium. 10. Zoospore 7-10 x 400.

(After DeBary.)

8. WEEDS PREVENT THE PROPER CULTIVATION OF SOIL.

Weeds of certain types, particularly the perennial weeds, often
make it extremely difficult to cultivate a soil. This is especially
true of weeds like quack grass, which when present in the soil
make it difficult not only to cultivate, but to plow and harrow, and
also make the operation quite expensive. —

9. WEEDS MAY CAUSE CONDITIONS WHICH BREED DISEASES.

Dr. Evans says that tall weeds contribute to the breeding places
of mosquitos, and he thinks that in this way the mosquitos will
lead to malaria. It is a well-known fact that the pollen from
weeds like ragweed and goldenrod cause hay fever and for this
reason these weeds should always be removed.

10. WEEDS MAY POISON THE SOIL.

There has long been a popular impression that weeds excrete
poisonous substances which render the soil unfit for a succeeding
crop. In regions where cockleburs are common, it is quite difficult
to get a good stand of clover. Mr. E. B. Watson found that

682 WEED FLORA OF IOWA

is}

Fig. 529

Fic. 529. Powdery Mildew of grasses (Hrysiphe graminis). This is common on
Wild Barley, occurs also on Wheat. a, mycelium and erect conidiophores;
b, e, conidia.

Fic. 530. Cocklebur (Xanthium canadense). There is a widespread belief that
Cocklebur and other weeds may excrete a substance which is injurious to
other crops.

elover would not do as well in soil of this character, nor did the
clover seed germinate as well, as in check soils. However, this
subject has been investigated but little. Then there is the larger
question of the actual antagonism between roots in occupied soils
that should be oceupied by the roots of agricultural plants.

11. WEEDS STOP DRAINS.

Drain tiles are frequently filled with a growth of the roots of
weeds, causing stoppage and often much expense in removing the
difficulty.

INJURIOUSNESS OF WEEDS 683

12. POISONOUS WEEDS.

There are many weeds which are injurious to man and to ani-
mals because they are poisonous. One of the best known illustra-
tions is the cowbane, one of the most deadly poisonous plants in the
state; then there are jimson weed, also poisonous; and poison ivy,
which is poisonous to the touch.

A large number of weeds, while not strongly poisonous, are in-
jurious ; some taint cow’s milk; some are injurious because of spines
and prickles and thorns. This subject has been treated in full in a
large book by the writer, ‘‘A Manual of Poisonous Plants.’’ Too
little attention has been paid by the school teachers of the state to
the subject of poisonous plants.

Fig 5381. Poison Ivy. Leaves poisonous to many people when they come in
contact with the plant.

CHAPTER IX.

WEED MIGRATION

CHAPTER IX.

WEED MIGRATION.

Geographical botany is that phase of botany which concerns itself
with the distribution of plants over the earth’s surface. The study
involves questions of geology, climatology, plant physiology, geog-
raphy, paleobotany, ethnology, history, agriculture, horticulture
and commerce. J. Burtt Davy says: ‘‘The facies of the world’s
flora is rapidly changing, and tends to become more uniform, within
certain limits, under the influence of agriculture and commerce.’’
Before the advent of man the chief factors in weed immigration
were the wind, water, snow, animals of various kinds, e. g., birds,
mammals, reptiles, insects and gravity. Primitive man must have
been an important factor in the distribution of plants. Many
plants were no doubt widely scattered by the Indian. Some, like
the persimmon, plum, pawpaw, maize, etc., were cultivated; but
many weeds also were scattered by the Indian, finding a congenial
environment near the wigwams. Commerce and the quest for new
lands distributed many species far and wide. Lists of weedy plants
of every civilized country, as indicated by Fernald, Davy, Gray
and other botanists, show that a large percentage are foreigners.
With the rapidity of modern transportation and with communica-
tion with every part of the world, weed seeds have naturally been
carried with the commercial products. Without exception, wherever
agriculture has advanced in Iowa, I believe weeds have followed
cultivation, generally making their appearance along the water
courses where our agriculture was fostered earlier than in the in-
terior of the state. For instance, such weeds as Jimson weed,
Indian mallow, burdock, mayweed or deg fennel, cheeses, mullein,
dock, black nightshade, smartweed, bull thistle, pigweed, lamb’s
quarters, and purslane, have been known in Jowa for more than
sixty years. Some of these were abundant species in cities and on
farms along the Mississippi long before central and northwestern
Iowa became settled. There are regions in northwestern Iowa
where some of the above weeds are still unknown. The mayweed,
velvet weed and mullein were only infrequent weeds in central
Iowa twenty-five years ago, though becoming more frequent from

688 WEED FLORA OF IOWA

year to year. Commerce indeed has taken an important part in
the migration of weeds. Wild carrot, chicory, black medick, quack
grass, Canada thistle, shoo-fly and dodder are becoming more and
more abundant in the fields of Iowa. Many weeds, moreover, first
make their appearance in the vicinity of cultivated fields. In
nearly every case wild parsnip, tansy, shoo-fly, bouncing betty and
butter and eggs show the influence of cultivation.

ieee? :
Fig. 531A I Fig. 531A II

Fig. 531 A 1V Fig. 531A V Fig, 531A VI

Fic. 531-A. Seeds scattered with commercial seed. I. Quack Grass (Agropyron
repens). II. Corn Flower (Centaurea cyanus) ; scattered with flower seed,
a frequent escape from _ cultivation. II. Corn cockle (Agrostemma
githago) ; scattered with wheat, frequent in wheat fields. IV. Chicory
(Cichorium, intybus) ; seed frequently found in alfalfa seed. It has been
widely scattered in this way. V. Peppergrass (Lepidiuwm apetalum) ; wide-
ly scattered with timothy seed. VI. Parsnip (Pastinaca sativa); a fre-
quent escape from cultivation.

(I and V, drawings, Charlotte M. King; II and IV, drawings, Ada Hayden;

III and VI, Hillman.)

Every phytogeographer is confronted with the problem of placing
weeds of the given area in their relation to other floras. Let us
take as an illustration a virgin Iowa prairie covered with a close
mat of such plants as the blue stems (Andropogon scopartus and
A. furcatus), vetch (Vicia americana), meadow rue (Thalictrum

WEHED MIGRATION 689

N,

ae:

eZ

=

—

_—

Trig. 532. Blue Stem (Andropogon scoparius). A plant common to the
prairies of Iowa. a, spikelet; b, e¢, first and second glumes; d, third
glume; f, lodicules stamens and pistil.

(Lamson-Scribner, U. S. Dept. Agr.)

purpurascens), black-eyed Susan (Rudbeckia hirta), Scribner’s
panic (Panicum scribnerianum), Philadelphia lily (Liliwm phila-
delphicum), lobelia (Lobelia spicata), sorrel (Oxalis violacea),
closed gentian (Gentiana andrewsii), goldenrods (Solidago mis-
souriensis and S. rigida), aster (Aster laevis, A. azwreus) and a
host of other associates. Compare with this an area in the Wis-
consin drift where such plants as blue vervain (Verbena stricta),
coreopsis (Coreopsis palmata), side oats (Bouteloua curtipendula) ,
needle-grass (Stipa spartea), perennial ragweed (Ambrosia psilo-

stachya), sunflower (Helianthus occidentalis), white aster (Aster
44 ;

690 WEED FLORA OF IOWA

Fic. 532-A. Prostrate Pigweed (Amaranthus blitoides.)
(Photographed by Hart.)

multiflorus), fragrant goldenrod (Solidago odora), and many others
occupy the ground. What becomes of the flora when the sod and
its flora have borne their own peculiar vegetation? Comparatively
few of the original inhabitants thereof remain as a part of the flora.
The weeds most likely to appear here are such as have been partially
adjusted to the open conditions. In such places it was not un-
common in the early days to find that such weeds as the common
Towa tumble weed (Amaranthus graecizans), tickle-grass (Panicum
capillare), creeping verbena (Verbena bracteosa), milk spurge or
milk purslane (Huphorbia maculata and E. geyert), evening prim-
rose (Oenothera biennis), horseweed (Erigeron canadensis), blue
vervain (Verbena stricta), persisted for a few years, perhaps with a
few other perennial weeds like flowering spurge (Euphorbia corol-
lata), Helianthus occidentalis and Desmodium canescens, especially

WEED MIGRATION 691

in a few places where tillage was not good; but in nearly every
case these perennial weeds disappeared from the cultivated fields
which thereupon became occupied by a large number of native
annual weeds like the greater ragweed (Ambrosia trifida), Spanish
needle (Bidens frondosa, B. discoidea) and smartweed (Polygonum
sp.), a few hardy perennial weeds like milkweed (Asclepias
syriaca), morning-glory (Convolvulus sepium), artichoke (Helian-
thus tuberosus) and meadow sunflower (Helianthus grosseserratus).
Such annual or winter annual weeds as squirrel-tail grass (Hordeum
jubatum), peppergrass (Lepidiwm apetalum) began to compete
with a host of European and other exotic weeds like lamb’s quarters
(Chenopodium album), persicaria (Polygonum persicaria), purslane
(Portulaca oleracea), foxtail (Setaria glauca, S. viridis) and, later,
crab grass (Digitaria sanguinalis and D. hwmifusa). In grain

Fic. 5383. Greater Ragweed (Ambrosia trifida). This weed rapidly occupies
cultivated ground.
(Vasey, U. S. Dept. Agr.)

692 WEED FLORA OF IOWA

fields or flax fields appeared the usual crop of weeds that are car-
ried with grain, like corn cockle, chess, cow-herb, mustard, penny-
eress and darnel. Then came the weeds which were introduced
with clover seed as buckhorn, dodder, evening catchfly, chicory,
wild carrot, ete.

Fic. 534. Small Peppergrass (Lepidium apetalum). Rapidly occupies the vir-
gin soil.
(Drawing by Charlotte M. King.)

As our agriculture shifted from a wheat country to one domi-
nating in corn, the weed flora changed slightly. Corn cockle, chess
and vetch (Vicia sativa), so common everywhere in a small grain
country, disappeared over a large section of Iowa. They are again
appearing where wheat is grown. Charlock, a relic of fiax culture,
remained to be distributed largely with oats seed.

WEED MIGRATION 693

The fact, however, remains that a goodly number of our Iowa
weeds are indigenous to this state. Many of these were plants
capable of enduring sunshine and so did not have to readjust them-
selves to new conditions. So we have received not only from Iowa
but from the country to the west, as Nebraska and the Dakotas,
such plants as the squirrel-tail grass, buffalo bur, winged pigweed,
common sunflower (Helianthus annwus), and stinkweed (Cleome
serrulata) . ;

The same thing has occurred in states to the west where many
indigenous weeds are vying with the European weeds. To the
north in Canada a pigweed (Monolepis nuttalliana) has become ex-
tremely common, while such weeds as foxtail are troublesome to a
limited extent only. The holy grass, a curiosity in many parts of
Towa, is a troublesome perennial weed of Manitoba.

It would seem to me that it is not a question of self-fertilization
or plasticity but one of tolerance of weeds for sunshine and ready
means of dissemination either by natural agencies or by man.

Kabsch, in a discussion of this problem, notes that precisely the
same things have occurred in various parts of the world where the
forests have been cleared. In Bolivia, Pteris, Anemia, Saururus,
Inlicoya were followed later by small shrubs of the Hupatoriaceae
and Malvaceae. In Brazil, Pterts caudata and Tristegis glutinosa
_make their appearance after the forest fire. In Teneriffe, in 1815,
Pteris, in 1820, Erica arborea, and in 1830 Laurus canariensis cov-
ered the ground. Kabsch notes how suddenly the vegetation of
a forest changes in Europe when sunshine is.admitted after a
forest fire or after the clearing of the forest. Plants like vetchling
(Orobus), four-leaved grass (Paris quadrifolia), Arum, lovers of
the shade, soon succumb, and in their places fireweed (E'pilobium
angustifolium), bedstraw (Galium), thistle (Cirsium), wild mar-
joram (Origanum), foxglove (Digitalis), and others appear to be
followed later by roses, brambles, hazel nut, birches, and grasses
like reed bent grass (Calamagrostis epigetos), meadow grass (Poa),
sweet vernal grass (Anthoxanthum odoratum), and bear moss
(Polytrichum commune). Water shade-loving plants have a chance
to grow.

In the Pacific northwest the fireweed (Epilobium angustifolium)
and common brake (Pieris aquilina) occupy the ground after a
forest fire. Velvet grass (Holcus) and groundsel (Senecio) are
followed by Spiraeas and the California blackberries (Rubus
ursinus and R. nutkanus) which in turn are succeeded by young

694 WEED FLORA OF IOWA

SAARINEN ay \
Bas a Zo
PH Zr NSS ) 3S Bad
\ r f i LR i = b ti

Fic. 535... Common Brake (Pieris aquilina). A troublesome weed following
fires in the northwest, also under similar conditions in some parts of
northeastern Iowa.

(Drawing by Charlotte M. King.)

forests of Douglas fir. In places, the red cherry (Prunus emar-
ginata) may occupy the soil for a long time. Cusick states that
the ‘‘elkweed’’ of eastern Oregon, more commonly called fireweed,
the only herbaceous plant to follow the fires, is followed in a year
or so by the lodge pole pine (Pinus murrayana) and Oregon fir
(Pseudotsuga taxifolia). In western Oregon it takes more time;
the ground is covered with a thick growth of blackberry plants.
In the Rocky mountains the conditions are somewhat different.
The first year after a fire very few plants will grow; but among
the first, mention may be made of fireweed (Epilobium angusti-
folium). thistle (Cirsium drummondii and the variety acaulescens,
C. eriocephalum and foliosum), groundsel (Senecio canus), (and in
moist places 8. triangularis), painted cup (Castilleja integra), wild

‘WEED MIGRATION 695

heliotrope (Phacelia sericea), stone crop (Sedum stenopetalum),
arnica (Arnica cordifolia). During the first year the vegetation is
frequently widely scattered, much depending on the source of the
seed. The lodge pole pine may not reappear on the burnt area
for a long time. Here again much depends on the distance from
which the seed has to come.

An Iowa forest, burned over, is covered by bull thistle (Cirsiwm
lanceolatum), fireweed (Erechtites hieractfolia), horseweed (Krige-
ron canadensis), whiteweed (Erigeron annuus), followed later by
small perennials, as blue grass, goldenrods, asters and sunflowers;
then hazel, coral berry, hawthorns, elms, poplars, maples and oaks.

J. Burtt Davy* in an interesting account of alien plants spon-
taneous in the Transvaal enumerates 141 species alien to that part
of Africa; of these 15 are now so cosmopolitan that their original
home is not known. Two were unidentified. The origin of these

Fic. 536. Lamb’s Quarters (Chenopodium album). A common foreign weed.
; Native to Europe. y

*Rep. S. Afr. Ass. Adv. Sci. 1901; 252-299.

696 WEED FLORA OF IOWA

alien immigrants he gives as follows: Mediterranean region, 33
species; tropical America and warm temperate regions, 13; tropical
Africa, 16; Australia, 1; temperate North America, 1; temperate
South America, 1; uncertain origin, 16. It is interesting to note
that the following Iowa species are abundant and troublesome in
the Transvaal (the exceptions being capitalized): mayweed
(Anthemis cotula), black mustard (Brassica NIGRA), hemp (Can-
nabis sativa), shepherd’s purse (CAPSELLA BURSA-PASTORIS), g00se-
foot (Chenopodium album), wormseed (Chenopodium ambro-
sioides), nut grass (Cyperus esculentus), jimson weed (Datura
stramomum), wire grass (Hleusine indica), fleabane (Erigeron
canadensis), shoo-fly (Hibiscus trionum), common morning-glory
(IPOMOEA PURPUREA), toad flax (LINARIA VULGARIS), darnel (Lolium
temulentum), lady’s sorrel (Oxalis corniculata), ribgrass (Plantago
lanceolata), common plantain (Plantago major), black bindweed
(PoLYGONUM CONVOLVULUS), larger knotweed (Polygonum erectum),
purslane (Portulaca oleracea), jointed charlock (Raphanus rapha-
nistrum), sheep sorrel (Rumex acetosella), yellow dock (RuMEX
CRISPUS), smooth tobacco (Nicotiana glauca), cow-herb (SAPONARIA
VACCARIA), bristly foxtail (Setaria verticillata), black nightshade
(Solanum mgrum), dandelion (Taraxacum. officinale), chickweed
(Stellaria media), sow thistle (SONCHUS OLERACEUS), goat’s beard
(TRAGOPOGON PORRIFOLIUS), vetch (VicIA SATIVA). In addition to
the above plants, Davy lists quite a number which are common in
the states to the south of Iowa and in California. Such: plants as
castor-oil bean (Ricinus communis), zinnia (Zinnia pauctflorus),
marigold (Tagetes erecta), cosmos (Cosmos bipinnatus), cockscomb
(Celosia cristata), four-o’clock (Mirabilis jalapa), evening primrose
(Ocenothera grandiflora), Xylopleurum tetrapterum, Mexican poppy
(Argemone mexicana) are commonly cultivated in Iowa. Some, like
Argemone, Oenothera and Cosmos, occasionally escape in Iowa. In
a classification of these weeds, Davy places the alien plants under
the following heads: I. Colonists (species not yet showing signs
of spreading) ; shepherd’s purse (Capsella bursa-pastoris), cat*s-ear
(Hypochaeris radicata), (one of the most common weeds on the
Pacific coast and spreading in New England, not reported from
Towa), black bindweed (Polygonum convolvulus) (common every-
where in Iowa), toad-flax (Linaria vulgaris) (common in the
north). II. Adventive (occasional, but spreading).; mayweed
(Anthemis cotula), Mexican poppy (Argemone mexicana), Cosmos
bipinnatus, morning-glory (Ipomoea purpurea), darnel (Loliwm

“WEED MIGRATION | 697

Fic. 537. Caster Oil plant. Cultivated as an ornamental plant in Iowa, but a
troublesome weed in South Africa.
(After Faguet.)

temulentum), plantain (Plantago major), ribgrass (Plantago
lanceolata), sheep sorrel (Rumeax acetosella), curled dock (Rumex
crispus), black nightshade (Solanum nigrum), dandelion (Taraxa-
cum officinale), cow-herb (Saponarta vaccaria), vetch (Vicia sa-
twa): III. Common; spiny amaranth (Amaranthus spinosus),
goosefoot (Chenopodium album), hemp (Cannabis indica), nut
grass (Cyperus esculentus), shoo-fly (Hibiscus trionuwm), lady’s
sorrel (Oxalis corniculata), purslane (Portulaca oleracea), castor-
oil bean (Ricinus communis), and caltrop (Tribulus terrestris).
TV. Abundant; (the most common species) purple amaranth
(Amaranthus paniculatus), sticktight (Bidens pilosa), jimson weed
' (Datura stramonium), purple thorn apple (Datura tatula),; wire

698 WEED FLORA OF IOWA

grass (Hleusine indica), Sida rhombifolia, spiny clotbur (Xanthium
spinosum), zinnia (Zinnia pauciflora).

\

Ss
SON \ ¥

Fie. 538. Spiny Clotbur. An abundant and troublesome weed in South Africa,
occasionally a weed in southeastern Iowa.
(After Thurber.)

As an example of the spread of American weeds in Europe sey-
eral weeds may be cited. The small ragweed (Ambrosia artemisiae-
folia), which is common throughout the United States, has accord-
ing to Laubert, been widely spread with American grown clover
seed™, though known in isolated places in Germany for forty years.
It is now on the increase, perhaps because of the recent clover
importation, yet its spread is somewhat limited because it blooms
late. The plants are often only pistillate. In Steglitz, Germany,
it was associated with black bindweed (Polygonum convolvulus),
fleabane (Erigeron canaudense), wall barley (Hordeum murinum),
ribgrass (Plantago lanceolata), common plantain (Plantago major),
wild carrot (Daucus carota), yarrow (Achillea millefolium) and
tumble weed (Corispermum hyssoptfolium) .

- *Landw. Jahrbucher. 35: 735-787.

‘WEED MIGRATION | 699

Fic. 538A. Caltrop (Tribulus terristris).
(Photographed by Colburn.)

Scherer and others record the occurrence of Solanum rostratum
in Germany (1883) and in France.

In Pflanzenleben, Kabsch says, ‘‘There are many illustrations of
plant immigrations and spreading of plants in Europe, but so far
as I know they have never occupied the soil to the same degree in
Europe as in America. Most of our weeds of fields, like the cereals
among which they grow, are of foreign origin, as star thistle
(Centaurea cyanus), corn cockle (Agrostemma githago), charlock
(Raphanus raphanistrum), Myagrum, ete.’’ There are many other
weeds of grain fields that are of similar origin that are not men-
tioned by Kabsch. Among them are the common mustard (Brassica
arvensis), common vetch (Vicia sativa), darnel (Lolium temulen-
tum), Russian thistle (Salsola kali var. tenutfolia), pennycress

700 WEED FLORA OF IOWA

{
‘

Fig. 539. Corn Cockle (Agrostemma githago). An immigrant from western
Asia.
(After U. S. Dept. of Agr.)

(Thlaspi arvense), false flax (Camelina sativa), Berteroa (Berteroa
meana and B. mutabilis). These weeds were undoubtedly spread
with the cultivation of grain. Many, though by no means all, were
brought to Europe with wheat during the early cultivation of grain
in Europe. The crusaders undoubtedly were responsible for the
spread of these small grain weeds in Europe... Other plants, of
which the horseradish is an illustration, were no doubt brought into
west Europe as cultivated plants.

It may not be out of place to give the expression of some of the
phytogeographical writers on the subject.

WEED MIGRATION 701

Sy
in WY o

=
iy

ze

7;

Fig. 540A Big. 540B

Fic. 540. A. Charlock (Brassica arvensis). B. Black Mustard (B. nigra).
Immigrants from western Asia brought to the United States by way of

Europe; early colonists.
(Dewey, U. S. Dept. of Agr.)

Warming and Vahl, in Oecology of Plants, speaking of the pam-
pas in South America and the European plants found there, say:

The pampas occupy the vast, rockless, alluvial, South American
plains that stretch from the Atlantic coast to the Andes, and from
Patagonia to the forests of Paraguay and Brazil. The boundless,
level or somewhat undulating, uniform, treeless surface is clothed
with perennial grasses and herbs, like ‘‘a shoreless sea of grasses
on whose horizon the eye finds no resting point, save where the
sun rises and sinks’’. The genera represented are Melica, Stipa,
Aristida, Andropogon, Pappophorum, Panicum, and Paspalum.
Between the grasses grow numbers of herbs belonging to various
families; these include Verbena, Portulaca, Apocynaceae, Com-
positae, Eryngium, and others. Curiously enough, there are very
numerous European species, which have succeeded in exterminating
the inland vegetation for miles and include not only such thistle-
like Compositae as Cynara cardunculus, Silybum marianum and
Lappa, but also Lolium perenne, Hordeum murinum, H. secalinum,

702 WEED FLORA OF IOWA

Medicago denticulata, and Foeniculum capillacewm. In the flora
of Buenos Ayres, according to Otto Kunze, at least three-quarters
of the species are introduced, and largely Mediterranean in source.

Roland M, Harper says:

Every botanist who attempts to classify the vegetation of a
populous region, such as the northeastern United States, is con-
fronted at the outset with the problem of distinguishing the natural
or undisturbed habitats from those which have been modified by
civilization. Of course all our vegetation has felt the influence
of civilization more or less, but it seems possible to draw a fairly
sharp line between those habitats whose flora is essentially the same
now as it was in* “prehistoric times and ‘those where it has been
so much altered that it is impossible to reconstruct the primeval
conditions.

In general it seems to be true—and the task of the phyto-
geographer. would be almost hopeless if it were otherwise—that
external influences of slight amount or of short duration produce
no permanent changes in vegetation. As an example of the first
kind,. when the pine trees are removed from an area of southern
pine- barrens the amount of sunlight reaching the ground is in-
creased probably not more than ten per cent, and this seems to
make .no perceptible difference to the herbaceous vegetation. But -
if the ground is then plowed up and cultivated, the original vege-
tation disappears, most of it never to return.

In the second place if a deciduous forest is destroyed by lumber-
men or swept by fire it presents a very different appearance for a
time, but if left undisturbed it will regain its former appearance
and flora, or very nearly so, as soon as the trees have time to
erow up again. But if the cutting or burning is repeated every
few years the ground will gradually become covered with herbs
and short-lived shrubs, among which it is difficult for trees to
regain a foothold.

M. L. Fernald has said along the same line:

The clearing of the forest lands and the letting in of the direct
sunlight is the inevitable forerunner of the farm and the village,
but it is as inevitably the death warrant of hundreds of native
plants. As is now well understood, a majority of our woodland
species have a root structure which allows them to grow only in
the moist, spongy humus of the forest or the swamp, conditions
as many of us know from practical experience, almost impossible
of artificial attamment. Try as we will, most if not all of us
have failed to imitate with sufficient skill permanently to satisfy
the plant the exact conditions which please the stemless lady’s
shipper (Cypripedium acaule), the trailing arbutus (Hpigaea), the
various species of Pyrola, the yellow wild foxgloves (Gerardia), the
painted-cups (Castilleja), or the fringed gentian; though in their
Heese haunts these plants bloom recularly and reproduce
reely.

WEED MIGRATION 71038

In their own wild homes, likewise, these and scores of other
species are almost as sensitive to change as when forced by man
into an unappreciated state of culture. The simple cutting of the
forest is to most of these plants disastrous, though such of them
as are very hardy will often linger until fire has swept the cleared
land and burned out the tinder-like humus. After the fire comes
a complete change of vegetation, and, during the interval before
the stumps are finally removed and the land turned by the plow,
the clearing too often becomes a tangle of fire cherry (Prunus
pennsylvanica), aspens (Populus tremuloides and P. grandidentata)
and other quick-growing trees and shrubs with a liberal mixture
of blackberry and raspberry bushes, fireweeds (Hpilobiwm and
Erechtites), rattlesnake-weeds (Prenanthes), and other coarse
plants which love the open and the direct sunshine. When the
final planting of the farm crop comes, however, these sturdy plants
of the burned land are quickly disposed of and rarely if ever do
they make themselves troublesome in the cultivated field.

E. W. Claypole, in speaking of the migration of weeds to
America, says:

Underneath the great wave of human emigration from the so-
called Old to the so-called New World, underneath the noisy, busy
surface tide that has swept westward from the shores of Europe
to those of America during the last two hundred years, there has
existed another and a less conspicuous wave, another and a less
prominent tide of emigration. Westward in its direction, like the
former, it hag silently accomplished results that seldom strike
the superficial eye, but yet are scarcely less in magnitude than
those which have followed the advent of the white man to the
shores of America.

I allude to that slow and noiseless immigration of European
plants which has been going on for many years, and which prob-
ably commenced when the first European vessel touched our shores.
Side by side with the displacement of the red man by the white
man has gone on the displacement of the red man’s vegetable com-
panions by plants which accompanied the white man from his trans-
Atlantic home. Not more completely have the children of the
pilgrim fathers made themselves at home on the banks of the
Charles and the Neponset, not more completely have the successors
of Champlain and Jacques Cartier established themselves along
the St. Lawrence, not more completely have the descendants of
the aristocratic colonists of Maryland and Virginia appropriated
the shores of the Chesapeake, than have the homely weeds of Eng-
land and France made themselves at home in the New World;
established themselves on its soil, appropriated its fields, its gar-
dens and its waysides. Nor have the older states alone been seized
by those European invaders. The stream has flowed beyond them,
and as no village or hamlet in the west is without its population

704 WEED FLORA OF IOWA

of European descent, so too it is never without its plant population
of European weeds.

Dr. Asa Gray, who discussed the subject of weeds from a phi-
losophical standpoint, said:

In the United States, and perhaps in most parts of the world,
a large majority of the weeds are introduced plants, brought into
the country directly or indirectly by man. Some, such as dande-
lion, yarrow, and probably the common plantain and the common
purslane, are importations as weeds, although the species naturally
occupy some part of the country.

Why weeds are so pertinacious and aggressive is too large and
loose a question; for any herb whatever when successfully ag-
gressive becomes a weed; and the reasons of predominance may be
almost as diverse as the weeds themselves. But we may inquire
whether weeds have any common characteristic which may give them
advantage, and why the greater part of the weeds of the United
States, and probably of similar temperate countries, should be
foreigners.

As to the second question, this is strikingly the case throughout
the Atlantic side of temperate North America, in which the weeds
have mainly come from Europe; but it is not so, or hardly so, west
of the Mississippi in the region of prairies and plains. So that the
answer we are accustomed to give must be to a great extent the
true one, namely, that, as the district here in which weeds from
the Old World prevail was naturally forest-clad there were few
of its native herbs which, if they could bear the exposure at all,
were capable of competition on cleared land with emigrants from
the Old World. It may be said that these same European weeds
here prepotent had survived and adapted themselves to the change
from forest to cleared land in Europe, and therefore our forest-
bred herbs might have done the same thing here. But in the
first place the change must have been far more sudden here than
in Europe; and in the next place we suppose that most of the
herbs in question never were indigenous to the originally forest-
covered regions of the Old World; but rather, as western and
northern Europe became agricultural and pastoral, these plants
came with the husbandmen and the flocks, or followed them, from
the woodless or sparsely wooded regions farther east where they
originated. This, however, will not hold for some of them, such as
dandelion, yarrow, and ox-eye daisy. It may be said that our
weeds might have come to a considerable extent from the border-
ing, more open districts on the west and south. But there was
little opportunity until recently, as the settlement of the country
began on the eastern border; yet a certain number of our weeds
appear to have been thus derived; for instance, Mollugo verticil-
lata, Erigeron canadense, Xanthium, Ambrosia artenusiaefolia,
Verbena hastata, V. urtictfolia, ete., Veronica peregrina, Solanum

WEED MIGRATION 705

Fig. 541A Fig. 541B

Fie. 541. A and B. Small Ragweed (Ambrosia artemisiaefolia). An immigrant
from the southern part of the United States.
(Vasey, U. S. Dept. of Agr.)

carolinense, various species of Amarantus and Euphorbia, Panicum
capillare, ete. Of late, and in consequence of increased communi-
cation with the Mississippi region and beyond—especially by rail-
roads—other plants are coming into the eastern states as weeds,
step by step, by somewhat rapid strides; such as Dysodia chrysan-
themoides, Matricaria discoidea, and Artemisia biennis. Fifty
years ago Rudbeckia hirta, which flourished from the Alleghanies
westward, was unknown farther east. Now, in twenty years, it has
become an abundant and conspicuous weed in grass fields through-
out the eastern states, having been accidentally disseminated with
red clover seed from the western states.

There are also native American weeds, doubtless indigenous to
the region, such as Asclepias cornuti, Antennaria margaritacea and
A. plantaginifolia, and in enriched soils Phytolacca decandra, which

45

706 WEED FLORA OF IOWA

NS
igre
Fic. 542. Tickle Grass (Panicum capillare). A common grass, probably orig-

inally found in clearings, has rapidly spread to cultivated ground.
(Lamson-Scribner, U. S. Dept. of Agr.)

have apparently become strongly aggressive under changed condi-
tions. These are some of the instances which may show that pre-
‘dominance is not in consequence of change of country and intro-
duction ‘to new soil.

In the interesting paper of Claypole the author argues that the
abundance of European weeds in North America is because Euro-
pean plants are more plastic than American plants. He says: But

a weed possessing a plastic nature—one capable of being moulded
by and to its.new surroundings—ere long adapts itself, if the
change is not too great or sudden, to its new situation, takes a new
lease of life, and continues in the strictest sense a weed.

Ts it not possible that some such cause as this may lie underneath
the facts we detailed in the earlier part of this paper? The true and
full explanation of the transfer of European species to America

WEED MIGRATION 707

should at the same time explain the absence of American species
from Europe. But the partial causes already alluded to fail to do
this. There is a residual effect for which they do not account.
May it not be true that the plants of the European flora possess
more of this plasticity, are less unyielding in their constitution, can
adapt themselves more readily to new surroundings, and thus secure
their continuance in the New World? And may it not be the lack
of this plasticity in the American flora which incapacitates it for
securing a foothold and obtaining a living in the different condi-
tions of the New World? Under the care of the gardener they
grow and embellish the gardens and conservatories of Europe, but,’
without this care they speedily fail and die.

Dr. Gray in a very friendly criticism of this paper remarked
that, ‘‘So far as we know, the greater plasticity of European as com-
pared with American plants is purely hypothetical. More plastic,
would mean of greater variability, which, if true, might be deter-
mined by observation. Because Europe once had more species or.
types in common with North America than it now has, it does not
seem to follow that the former has ‘a younger plant-life,’ or that
its existing plants are more recent than those of the American flora.
And as already intimated, so refined an hypothesis is hardly neces-
sary for the probable explanation of the predominance of Old World
weeds in the Atlantic United States.”

It is interesting to note the large number of plants which are con-
tinually being added to the flora of Europe. Bitter in his paper on
the adventive flora of Bremen notes that out of the 2,492 plants
listed by Garcke in his flora of Germany, 230 are adventive; Hock,
who published a paper on the plants of North Germany, lists 54
as weedy and ruderal.

The region embraced in North Germany probably contains as
many exotic weeds as Iowa. For our purpose let us compare foreign
weeds of Iowa with the native plants. Hitchcock, in his catalogue
of the plants of Ames and vicinity, lists 740 plants, of which 86 are
introduced and of these about one-third have not become perma-
nently established.

Dr. Charles Mohr in his paper on Plant Life in Alabama, states
that ‘‘fully one-sixth of the plants enumerated in the catalogue of
the Alabama flora as growing without cultivation are immigrants
from other regions, and but few of them are native in the more dis-
tant parts of the continent north of Mexico. They are mostly from
the warmer temperate, subtropical, and tropical regions of the Old
World. Those of widest distribution and which have gained the

708 WEED FLORA OF IOWA

firmest foothold are wanderers following civilized man in his con-
quest of the wilderness. Originally children of the open plain, ex-
posed to the extremes of heat, cold, drought, and excessive rain, these
plants necessarily acquire the widest elasticity in adapting them-
selves to new surroundings and possess the greatest power of re-
sisting adverse conditions.’’

THE DIRECTION OF WEED MIGRATION.

Mr. L. H. Dewey, who made a study of 200 North American
weeds and their migration, says: ‘‘A study of the origin of weeds
now in this country will impress one with the largeness of the num-
ber that have been introduced from Europe in comparison with the
number of native species or of species received from other direc-
tions.’’ In the list of 200 weeds of the United States published in
the Year Book for 1895, 108 species are of foreign origin, while 92
are native. Of the 108 introduced species, 64 are native in Europe
and 30 are ascribed to the Old World in general, only 2 Asiatic
species in the list having established themselves as weeds in this
country without being first distributed in Europe. Africa and
Australia are not represented among our weeds, while Central and
South America have contributed only 12 or 15 important species,
most of which are confined to the Gulf states. A list of the plants
of Michigan published in 1892 contains 1,604 indigenous species, of
which 22 are recognized as injurious weeds, and 142 species intro-
duced from Europe, of which 57 have become troublesome weeds.

A list of Kansas weeds enumerating 209 species contains 129 na-
tive species, 42, introduced from Europe, and 38 from all other
sources. Eighteen species native in the states east of the Mississippi
river have been introduced into Kansas in opposition to the pre-
vailing winds and the direction of the drainage, while only 3 species
are mentioned which have come from the Rocky Mountain region
with both of these natural forces in their favor.

In an article on the weeds of California 110 species are mentioned
as troublesome in that state. Of these, 53 are native, 43 are intro-
duced from Europe, 5 are from the eastern United States, 3 from
Central and South America, and only 2 from Asia. Even in the
states bordering the Gulf of Mexico the number of weeds introduced
from Europe in cultivated land equals or exceeds those from Mexico
and South America. Canada thistle, bur clover, and skunkweed
have been taken from California to Australia, where they quickly
become naturalized and are now rapidly spreading.

The weeds which haye followed civilization in America are,
shepherd’s purse, dandelion, sow thistle, stinging nettle, mallow,
plantain, chickweed, St. John’s-wort, yarrow, toadflax and purs-
lane. Manasseh Cutler, in 1783, reported 66 species, among them
buttercup, chicory and daisy. Dr. Bigelow, in Florula Bostoniensis,

WEHED MIGRATION 709

Fie. 543. Jimson Weed (Datura stramonium). An immigrant from India,
reached United States by way of Europe.
(After Chesnut, U. S. Dept. of Agr.)

1814, records 83 introduced species and in the edition of 1840, lists
140 species. Dr. Fernald says: ‘‘Gradually this list has increased
until we are forced to number among the wild plants of New
England more than 600 species which have been introduced through
human agency since the first cutting of the forests.’’ The causes
for the appearance of these weeds into New England, the west,
Pacific coast and elsewhere must be ascribed to the sowing of
seed that contained the weed seeds. Wheat always contained the
seed of cockle, mustard, vetch, etc., consequently we find that
these weeds are found wherever cereals are cultivated. Many
plants were, however, planted for medicinal purposes, among
which were peppermint, black henbane, tansy, chamomile, caraway,
peison hemlock, and a long list of other plants utilized by the Mor-
mons which have become weedy wherever these people have settled.
Even in Iowa we find that such plants as tansy, elecampane, jimson

710 WEED FLORA OF IOWA

weed, European morning-glory, shoo-fly, and others have been
spread from cultivation and have become weeds. In regard to the
introduction of plants, Dr. Fernald has stated the case very well
in the following paragraph:

A review of the history and spread of this vagrant class of
plants presents many aspects which are well worth consideration.
John Josselyn, in 1672, stated that several species of European
weeds had ‘‘sprung up since the English planted and kept cattle
in New England’’, thus implying that these plants had come un-
bidden or at least were not purposely brought to this country.
He records no less than 40 European weeds introduced in this
manner. According to a time-honored tradition, based perhaps on
fact, the first weed to spring up in the track of the pioneer is
plantain, and on this account it has been called by some primitive
races ‘‘White-man’s Foot’’, a name of more than fanciful appli-
cation; for without question the plantain and many other roadside
species are spread: directly by the foot of man. For some years
strange and outlandish weeds have been appearing along the river
below Waterbury, Connecticut. These plants, upon careful study,
prove to be vagrant species from geographically remote portions
of the world, and their presence along the Naugatuck river has

cs

PA
ae fee

<\ \\ 7; j

Fic. 544. Poison Hemlock (Coniwm maculatum). Common in Salt Lake Basin.
(After Chesnut, U. S. Dept. Agr.) ;

WEED MIGRATION 711

been. a mystery. Eventually, however, the whole matter was ~
cleared when the source of these plants was traced to a factory
which utilized old rubber shoes. These shoes were collected from
every available source, and, before being melted for their rubber
were stripped of the cloth linings which were thrown upon a rubbish
heap. These linings naturally contained seeds of innumerable
plants from the roadsides of every land, and the rains and spring
freshets of the Naugatuck valley gave them every opportunity to
scatter and to start life anew in Connecticut soil. In this or similar
ways many of the plants mentioned by John Josselyn, Manasseh
Cutler, and Jacob Bigelow undoubtedly reached our shores; and
these emigrants are being reinforced by almost every person who
comes to us from foreign lands.

Many weeds start in the proximity of woolen mills. Among
these are, teasel, buffalo bur, various borages, erodium, etc. Others
-are introduced with agricultural seeds. In recent years there

Fic. 545. Chicory (Cichorium intybus). An immigrant from Europe. a, flower-
ing branch; b, single head; e, single flower; d and e achene; e, cross
section. A

(U. S. Dept. of Agr.)

712 WEED FLORA OF IOWA

have been introduced into Iowa such weeds as wild carrot (Daucus
carota), Silene nocttflora, 8S. dichotoma, Cichorium intybus, Conium
maculatum, Centaurea solstitialis, Cirsium arvense, C. pratense,

Cuscuta arvensis, C. epithymum, Eruca sativa, and others, largely
with clover and alfalfa seed. Still another and frequent source
of the introduction of weeds is through the cultivation of orna-
mental plants which become weedy as: shoo-fly (Hibiscus trionum)
during recent years, the bouncing bet (Saponaria officinalis L.),
toad flax (Linaria vulgaris), Euphorbia cyparissias, live forever
(Sedum telephium), snow-on-the-mountain (Huphorbia marginata)
in many localities, pickerel weed (Eichornia crassipes) in Florida,
water chestnut (Trapa natans) in central New England. The or-
ange hawkweed (Hieracium aurantiacum), and others of this class
are excellent illustrations of how ornamental plants become weedy.
In some cases plants cultivated for food have become weedy, as
in Iowa, the horse radish; in California, the beet (San Francisco
Bay region) ; and in Utah and California, the spinach.

Fic. 546. Snow-on-the-Mountain (Huphorbia marginata). A western weed now
common: in some places in the east.
(After Chesnut, U. S. Dept. Agr.)

WEED MIGRATION 713

New introductions have come not only into western Hurope
from the United States, but from eastern Europe, Asia, and from
the tropical world. The Berteroa incana, a recent introduction
into Iowa, has. been reported in Germany by Scherer. The spiny
knapweed (Centaurea solstitialis), a recent lowa introduction, has
been reported from Germany by Lehmann, Bitter and Alpers. The
Galinsoga parviflora, an introduction from South America into
the United States, has been reported from northern France and
southern Germany by Kieffer. The storksbill (Hrodiwm mos-
chatum), the butterprint (Abutilon theophrastr), the spiny clotbur
(Xanthium spinosum) and the shoo-fly (Hibiscus trionum), are
common plants of the tropical regions everywhere; these have ex-
tended far northward. In recent years they have been reported in
north Germany by Bitter. He has likewise reported as recent in-
troductions the yellow sweet clover (Melilotus officinalis), Matri-

Fic. 547. Velvet Weed or Butterprint (Abutilon theophrasti).. A tropical weed
now common in the north and spreading to Hurope.
(U. S. Dept. of Agr.)

714 WEED FLORA OF IOWA

caria discoidea of Asia, Mexican fireweed ( Kochia scoparia), brome
erass (Bromus tectorum) in the vicinity of Bremen; all being in-
digenous to eastern Europe and western Asia.

Dr. Fernald states that of the species of plants growing in ‘he
British Isles, at an altitude of 3,000 feet in the mountain country,
where the primitive vegetation is but little disturbed, 68% are also
native to the mountainous regions of New England, but of the
species that occur everywhere at low altitudes and in thickly set-
tled and closely farmed districts only 23% are native to New Eng-
land while more than 50% have become established in New Engiand
as weeds; and that barely 1% of the plants of temperate Europe
have been imported from America, but every year adds to the new
weeds introduced into Europe.

Dr. Gray, in that interesting paper on the Pertinacity of Weeds,
refers to the book by Mr. Henslow on the Self-Fertilization of
Plants, in which the latter comes to the conclusion that weeds are
intrusive and dominating plants of great emigrating capabilities,
and have a longer ancestral life history than their more or less
aggressive relatives. Furthermore, this dominance may be at-
tributed to self-fertilization. In the list of weeds that Dr. Gray
mentions in this paper as the most abundant in eastern North
America and the southern United States, the rule evidently does
not hold that this dominance is due to self-fertilization; in fact
some of the most dominant of these plants are pollinated by in-
sects. For the sake of convenience I shall here use a list prepared
by Dr. Gray in 1879, adding to it weeds that are more or less pre-
dominant in the state of Iowa at the present time; the Iowa weeds
are printed in small capitals. There is a slight rearrangement,
according to present interpretation of taxonomists.

Gramineae.

DIGITARIA HUMIFUSA, Smooth crab grass.

D. SANGUINALIS, Crab grass.

PANICUM CAPILLARE, Old-witch grass.

P. DICHOTOMIFLORUM, Sprouting erab grass.
ECHINOCHLOA CRUSGALLI, Barnyard grass.
SETARIA GLAUCA, Pigeon grass.

S. viRIDISs, Green foxtail.

S. VERTICILLATA, Bristly foxtail.

CENCHRUS TRIBULOIDES, Sandbur.
Anthoxanthum odoratum, Sweet vernal grass.

WEED MIGRATION 715

MUHLENBERGIA MEXICANA, Mexican drop-seed. —
M. racemosa, Marsh muhlenberg.

M. Scureseri, Nimble Will.

SPOROBOLUS VAGINIFLORUS. Sheathed rush grass.
S. NEGLECTuS, Small rush grass.
ALOPECURUS PRATENSIS, Meadow foxtail.
A. GENICULATUS, Marsh foxtail.

Phleum pratense, Timothy.

AGROSTIS ALBA, Red top.

AVENA FATUA, Wild oats.

ELEUSINE INDICA, Wire grass.
ERAGROSTIS PILOSA, Southern spear grass.
E. MEGASTACHYA, Candy grass.

Dactylis glomerata, Orchard grass.

Poa annua, Low spear grass.

P. pratensis, Kentucky blue grass.

P. trwialis, Rough-stalked meadow grass.
P. compressa, Wire grass. é
BROMUS SECALINUS, Chess.

B. HORDEACEUS, Soft chess. -

B. ARVENSIS, Field brome grass.

B. TECTORUM, Downy brome grass.
Festuca pratensis, Meadow fescue.

F. ovina, Sheep’s fescue.

Lolium perenne, Common darnel.

L. TEMULENTUM, Poison darnel.
AGROPYRON REPENS, Quack grass.

A. caninum, Awned wheat grass.

A. Smirui, Western wheat grass.
HorpEUM JUBATUM, Squirel-tail grass.
H. pusituum, Little barley.

Cyperaceae.
CYPERUS ESCULENTUS, Nut grass.
Juncaceae.
JUNCUS TENUIS, Slender rush.
Liliaceae.
Allium vineale, Wild garlic.
Urticaceae.

CANNABIS SATIVA, Hemp.
URTICA GRACILIS, Nettle.

716 WEED FLORA OF IOWA

Polygonaceae.

RUMEX crIsPuS, Curled dock.

R. autissimus, Pale dock.

R. SANGUINEUS, Bloody dock.

R. ACETOSELLA, Sheep sorrel.
POLYGONUM AVICULARE, Knotweed.

. ERECTUM, Larger knotweed.

. LAPATHIFOLIUM, Slender smartweed.
. MUBLENBERGI, Marsh smartweed.

. PENNSYLVANICUM, Pennsylvania smartweed.
. ACRE, Water smartweed.

. PERSICARIA, Lady’s thumb.

. CONVOLVULUS, Black bindweed.

gel Ime} Io} tae} Inel Iqe} Ine]

Chenopodiaceae.

CHENOPODIUM Borrys, Jerusalem oak.

C. ALBUM, Goosefoot.

C. HyBRIpUM, Maple-leaved goosefoot.

ATRIPLEX PATULA, Orach.

CYCLOMA ATRIPLICIFOLIUM, Winged pigweed.
KocHia scoparia, Mexican fireweed.

SALSOLA KALI VAR. TENUIFOLIA, Russian thistle.

Amaranthaceae.

AMARANTHUS RETROFLEXUS, Green pigweed.

A. GRAECIZANS, Tumble weed.

A. BLITOIDES, Prostrate pigweed.

ACNIDA TUBERCULATA V. PROSTRATA, Water hemp

Nyctaginaceae.

OXYBAPHUS NYCTAGINEUS, Wild four-o’clock.

Caryophyllaceae.

STELLARIA MEDIA, Chickweed.

Cerastium nutans, Mouse-ear chickweed.
AGROSTEMMA GITHAGO, corn cockle (wheat secticns).
LYCHNIs ALBA, White campion.

L. dioica, Red campion.

Silene latifolia, Bladder campion.

S. noctirLora, Night-flowering catchfly.

S. ANTIRRHINA, Sleepy ecatchfly.

WHED MIGRATION 717

SAPONARIA OFFICINALIS, Bouncing Bet.
S. VACCARIA, soapwort (wheat sections).

Portulacaceae.

PORTULACA OLERACEA, Purslane.

Ranunculaceae.

RANUNCULUS ABORTIVUS, Small-flowered crowfoot.
R. bulbosus, Bulbous buttercup.

R. acris, Tall buttercup.

R. SEPTENTRIONALIS, Swamp buttercup.

Cruciferae.

BERTEROA INCANA, Alyssum.

THLASPI ARVENSE, F'renchweed.

LEPIDIUM VIRGINICUM, Large peppergrass.

L. APETALUM, Small peppergrass.

CAPSELLA BURSA-PASTORIS, Shepherd’s purse.
CAMELINA SATIVA, False flax.

NESLIA PANICULATA, Ball mustard.

RAPHANUS RAPHANISTRUM, Jointed charlock (northeastern Iowa).
BRASSICA ARVENSIS, English charlock.

B. nigrA, Black mustard.

SISYMBRIUM OFFICINALE, Hedge mustard.

S. ALTISsIMUM, Tumbling mustard.

RADICULA NASTURTIUM-AQUATICUM, Water cress.
R. ARMoRACIA, Horseradish.

BARBAREA VULGARIS, Winter cress.

Capparidaceae.
POLANISIA GRAVEOLENS, Clammy weed.
CLEOME SERRULATA, Stinkweed.

Resedaceae.

Reseda lutea, Dyer’s rocket.

Rosaceae.

GEUM CANADENSE, White avens.
Rosa PRATINCOLA, Prairie rose.

718 WEED FLORA OF IOWA

Leguminosae.

CASSIA CHAMAECRISTA, Partridge pea.
Gensta tinctoria, Dyer’s greenweed.
CROTALARIA SAGITTALIS, Rattle-box.
Trifolium arvense, Stone clover.
T. PROCUMBENS, Low hop clover.
T. procumbens, Low hop clover.
T. repens, White clover. ;
MELILOTUS OFFICINALIS, Yellow sweet clover.
M. auBa, White sweet clover.
MEDICAGO LUPULINA, Black medick.
DALEA ALOPECUROIDES, Pink dalea.
ROBINIA PSEUDO-ACACIA, False acacia.

_ GLYCYRRHIZA LEPIDOTA, Liquorice.
VIcIA SATIVA, Vetch.
V. villosa, Hairy vetch.
STROPHOSTYLES PAUCIFLORA, Wild bean.

Oxalidaceae.

OXALIS CORNICULATA, Lady’s sorrel.

Geraniaceae.

GERANIUM MACULATUM, Wild cranesbill.

Euphorbiaceae.

ACALYPHA VIRGINICA, Three-seeded mercury.
EKUPHORBIA PRESLI, Large spotted spurge.
E. MACULATA, Spotted spurge.

EK. COROLLATA, Flowering spurge.

EK. CYPARISSIAS, Cypress spurge.

Malvaceae,

ABUTILON THEOPHRASTI, Butterprint.
SIDA SPINOSA, Prickly sida.

MALVA ROTUNDIFOLIA, Cheeses.
HIBISCUS TRIONUM, Shoo-fly.

Onagracedae.

OENOTHERA BIENNIS, Evening primrose.
GAURA BIENNIS, Biennial gaura.

WEED MIGRATION 719

Umbelliferae.

Conium maculatum, Poison hemlock.
CaRUM CARVI, Caraway.

PASTINACA SATIVA, Wild parsnip.
Daucus carora, Wild carrot.

Primulaceae.

Anagallis arvensis, Pimpernel.

Apocynaceae.

APOCYNUM ANDROSAEMIFOLIUM, Spreading dogbane.
A. CANNABINUM, Indian hemp.

Asclepiadaceae.

ASCLEPIAS SPECIOSA, Showy milkweed.
A. syrtAcA, Milkweed.

Convolvulaceae.

CoONVOLVULUS SEPIUM, Wild morning-glory.
C. ARVENSIS, European bindweed.

CuscuTA EPITHYMUM, Clover dodder.

C. arvensis, Field dodder.

Hydrophyllaceae.

ELLISIA NYCTELEA, Waterleaf.

Boraginacede.

CYNOGLOSSUM OFFICINALE, Hound’s tongue.
LAPPULA ECHINATA, Stickseed.

Symphytum officinale, Comfrey.

Echium vulgare, Blue weed.

Verbenaceae.

VERBENA BRACTEOSA, Bracted vervain.
V. HastTaTA, Blue vervain.
V. stricta, Hoary vervain.

Labiatae.

NEPETA CATARIA, Catnip.
N. HEDERACEA, Ground ivy.
Lamium amplexicaule, Dead nettle.

720 WEED FLORA OF IOWA

Leonurus cardiaca, Motherwort.
Mentha piperita, Peppermint.

M. spicata, Spearmint.

Satureja nepeta, Thyme.

S. VULGARIS, Basil.

Marrubium vulgare, Hoarhound.
Galeopsis tetrahit, Hemp nettle.
SoLANUM NiGRUM, Black nightshade.
S. CAROLINENSE, Horse nettle.

S. ROSTRATUM, Buffalo bur.
DATURA STRAMONIUM, Jimson weed.
D. ratuLA, Purple thorn apple.
VERBASCUM THAPSUS, Mullein.

V. blattaria, Moth mullein.

LINARIA VULGARIS, Butter and eggs.
VERONICA PEREGRINA, Speedwell.
PLANTAGO MAJOR, Common plantain.
P. RUGELU, Rugel’s plantain.

P. LANCEOLATA, Ribgrass.

P. ARISTATA, Bracted plantain.

Compositae.

ERIGERON ANNUUS, Daisy fleabane.

EH. CANADENSIS, Fleabane.

E. RAMOsUS, Whiteweed.

Iva XANTHIFOLIA, Marsh elder.

AMBROSIA ARTEMISIAEFOLIA, Smaller ragweed.
A. TRIFIDA, Greater ragweed.

XANTHIUM CANADENSE, Cocklebur.
Gnaphalium uliginosum, Cudweed.

Inula helenium, Elecampane.

HELIOPSIS SCABRA, Ox-eye.

RUDBECKIA HIRTA, Cone-flower.

HELIANTHUS ANNUUS, Common sunflower.
BIDENS FRONDOSA, Beggar-ticks.

B. piscoipEA, Small beggar-ticks.

DyssopIA PAPPOSA, Fetid marigold.

ACHILLEA MILLEFOLIUM, Yarrow.

ANTHEMIS COTULA, Mayweed.
CHRYSANTHEMUM LEUCANTHEMUM, Ox-eye daisy.
TANACETUM VULGARE, Tansy.

WHED MIGRATION 721

ARTEMISIA BIENNIS, Wormwood.
ERECHTITES HIERACIFOLIA, Fireweed.
AROTIUM LAPPA, Burdock.

CIRSIUM LANCEOLATUM, Bull thistle.

C. ARVENSE, Canada thistle.

C. CANESCENS, Woolly thistle.

CICHORIUM INTYBUS, Chicory.

Leontodon autumnalis, Hawkbit.
TARAXACUM OFFICINALE, Dandelion.

T. ERYTHROSPERMUM, Red-seeded dandelion.
SONCHUS ASPER, Spiny-leaved sow thistle.
LActTuca scArRIoua, Prickly lettuce.

L. SCARIOLA VAR. INTEGRATA.
LiDGODESMIA JUNCEA, Lygodesmia.
SOLIDAGO CANADENSIS, Goldenrod.

eZ
WA <2

Fic. 548. Narrow Sneezeweed (Helenium tenuifolium). General aspect of plant
and a single head enlarged.
(After Chesnut, U. S. Dept. Agr.)

46

722 WEED FLORA OF IOWA

Dr. Gray, in the above list mentioned 86 weeds which are more
or less aggressive in the Atlantic United States. It would seem,
however, that comparatively few of the aggressive weeds of the
Gulf states are enumerated in the list. The more important gulf
coast weeds are sneezeweed (Heleniwm tenwifolium), Louisiana car-
pet grass (Paspalum platycaule), Johnson grass (Sorghum hale-
pense), beard grass (Andropogon virginicum), buffalo bur (Sola-
num rostratum), prickly sida (Sida spinosa), southern nut grass
(Cyperus rotundus), wild pansy (Viola arvensis). Dr. Mohr gives
the following list of weeds as the most conspicuous by their
abundance all over the state of Alabama.

Fic. 549. Johnson Grass (Sorghum halepense). An African weed. Common
in the Gulf states, and reported from southwestern Iowa.
(Lamson-Scribner, U. S. Dept. Agr.)

WEED MIGRATION 723

Leptochloa mucronata, Yard grass.
Manisurus granularis, Manisurus.
Cyperus rotundus, Southern nut grass.
Amaranthus retroflecus, Green pigweed.
Amaranthus hybridus, Pigweed.
Amaranthus spinosus, Spiny amaranth.
Spergula arvensis, Corn spurrey.
Portulaca oleracea, Purslane.

Cassia occidentalis, Senna.

Cassia tora, Low senna.

Sida rhombifolta, Rhombleaf sida.

Sida spinosa, Prickly sida.

Senebiera pinnatifida, Peppergrass. -
Veronica peregrina, Neckweed. _
Veronica arvensis, Corn speedwell.
Lamium amplexicaule, Dead nettle.
ichardia scabra, Mexican clover.

Dr. W. A. and Mrs. Kellerman in a paper on the non-indigenous
Flora of Ohio, state that out of 2,060 plants of the state 430 are
not indigenous. Of the latter number 326 have come from Europe,
30 from Asia, 2 from Africa, 46 from Southern and Western United
States and 21 from tropical or South America. When expressed
in percentages the numbers are as follows: from Europe, 75.81% ;
from Asia, 6.99%; from Africa, 0.47%; from the United States,
10.70% ; and from tropical and South America, 4.81%.

Comparing the Old World species with those from parts of the
American continent we find the numbers to be 358 and 67 re-
spectively. Therefore 83.25% of the introduced species have come
from the eastern hemisphere and 15.58% from America.

Expressed in percentages of the total number of introduced
species they are as follows: waifs, 11.86%; occasionally escaped,
38.84% ; and thoroughly naturalized, 49.30%.

The following list shows the families represented and the number
of species in each.

1. Amaranthocece, Amaranth’ Mamily <3. 0.0 0.6... 6 62. 5)
2 Anzoaceae., Carper Wiced ebay tie isk cid isis cin ce 2 oes Se 1
a. Aipocynaceae. Wogbanes HM amitllyges cc. 6 sisi cas ss oe sso eles 2
4. Bergeridnucecemparherty, sMamithy 3 os cs6 vee ee ss ne ee ae a
5A MB tgMomaccae a ioramiataninihys 2%. 45 = tls sans ee ds ese 2
G2 BOVGGINGCCUC Ms OCAS ee AMM Aes oa.) iseaysie era a vic es + ons cee 11

WEED FLORA OF IOWA

Cactaceac, Cactus: Wamilyegier 2 8): 1) ee 1
Campanulaceae, Bluebell Family ..................-.-.- aM
Capparidaceae, CapersHamily.): 0.2. ce oe. il
Caprifoliaceae, Honeysuckle Family .................... 4
Caryophyllaceae; PinksWamily- ..\.c.08 oo: 4. © ee 23
Chenopodiaceae, Goosefoot Family ...................-. i
Compositae; Thistle Wamiully’ 67. <2. Saeko oes ae 88
Convolvulaceae, Morning-glory Family .................. 8
Crassulaceae,, Orpines amily. .¢ 2). bags ces: eee 2
Cruciferae, MustardMamily | 22 -\c0 to. 2 ne eee 27
Cucurbriaceae, Gourd) Bamily <. 22.202) ee 6
Cyperaceae, (SedgewMamily. ... 2.036502 -- + a ee bs
Dipsacaceae, easel’ Hamil y” 22)2e cic oe if
Hilatinaceae a WwWaterwort Hamiuliycn 2 ene. lc ts ene aL
Euphorbiaceae, spurge Family .40). 2445-5 if
Fumariacese, Mumitory Wamiuly oy. oe 2... eee iT:
Geranvacese; Geranium Kamily \i25 2.22. eee 5
Gramimnede Grass’ Family (4c 2) ee. eee a Se Ss 46
Hypericaceae, St. John’s-wort Family................... 1
Labvatae, Ment MB amnily viii. otek ides etait: oie ee ee 24
Leguminosae, Pulse:\Eamily:) 2.25). 2ce 28 8 ee 19
Enhiacene, Wily: Bamily 232.22... fs le 7
Linaceae, Wilax Family osc ons eis ene 2 eo a
Malvaceae, Mallow’ Wamily 2.225.522 - |) ae 9
Mariyniaceme, Nartynia Kamilys= 24-244) se eee 1
Nyctagimaceae, Four-o’elock Family =... /.......2.-20 9. 2
Oleaceae, (Olive: Family 2.8 2825 a 6 es a ae ee 2
OxnalidacegeOxalis Family 2 tie see ae er 1
Onagraceae, Evening primrose Family .................. 3
PapaveracesesPoppy amily, (2.820. se eee 5
Plontagmmaceae; Plantain’ Pamily 30.22. --\25- . 2. +
Polygonaceae. Smartweed Hamily, 3.4.50. 22-2 eee 14
Portulacaceae, seurslane Wamily ii. 5. eo 1
Primulaceces erimrose: Mamilyjaias oe oe eke a 2
Ranunculactae, Crowtoot Kamily <2. 322.5. eee 9
Resedaceae,g\iisnonette. Hamil. 0 25). 27k). aes eck 3
Rhamnaceae, Bucktnorn: Mamily. 2 sos: cis elo ee uy
Rosaceae, Iwose) Hamnlyc.. 2... .Succ. saps ccctpee eae eee a 15
Rubtaceae, Madder Mamily.. \.)5. 26 eta seir se eee 3
Saticaceae, Willow Wamaily....... 0s... 5-- +. och eee 8

Saxifragaceae, Saxitrage: Wamily < 202 ce ee | ole +

WHED MIGRATION 725

48. Scrophulariaceae, Figwort Family.....:.............+... 14
ae SimarwogcederOuassiankamily 27. oc sme nak cicyes © <> lo = il
D0. Solavacedow Nie Mismadesmamily 55 2. Seams eiee es 5 ee: 9
NE NUNLO CLO Cracmmam leven almiliy so... 5. ln me eran rq eee ows. a aa ae alt
Benes UTULCOCEUe wNGtUleMU aM Yin 020. ct le cnt ge) Meee etch ses + oom « 5)
jon. Valeranacedos Valerian Wamily.. 5 i205 ee oon Sens oe i
pia, Verbenaceaeverbenaub amily : 022 2-38 leis sare oie e'o es it
Dm) a ViLOLACCRC MNO ley MCA eh es «Sie ike «aw date ty Apricorn cte «14 il

The weeds of the Pacific coast are somewhat different from those
of the Atlantic coast. Eugene Hilgard, in a series of interesting
articles in Garden and Forest, some years ago, S. B. Parish, J.
Burtt Davy and other California botanists, have contributed notes
on the introduction of these weeds of the coast. They enumerated
the more important weeds, among which mention may be made of
black mustard: (Brassica nigra), catchfly (Silene gallica), storksbill
(Erodium cicutariwm), musk erodium (Hrodium moschatum),
small-flowered mallow (Malva borealis), black medick (Medicago
lupulina), bur clover (M. denticulata), white sweet clover (Meli-
lotus alba), and yellow sweet clover (M. officinalis), star thistle
(Centaurea cyanus), knapweed (C. solstitialis), brown knapweed
(C. jacea), black knapweed (C. nigra), wild carrot (Daucus car-
ota), beet (Beta vulgaris), spinach (Spinacia oleracea), lady’s
thistle (Silybum marianum), cotton thistle (Onopordon acanthiwm),
dodder (Cuscuta epithymum).

The writer recently noted the following weeds in the San Fran-
cisco Bay region, Oakland, and Sacramento, many of our eastern
weeds being common among them: Hedge mustard (Sisymbrium
officinale), Raphanus sativus, Marrubium vulgare, dock (Rumex
crispus), cheeses (Malva rotundifolia), mallow (M. crispa), bull
thistle (Cirsium lanceolatum), sow thistle (Sonchus oleraceus),
eat’s-ear (Hypochaeris radicata), knotweed (Polygonum erectum),
black medick (Medicago lupulina), Brassica campestris, lamb’s
quarters (Chenosodium album), chickweed (Stellaria media), Poa
annua, Alfilaria (Hrodwm cicutaria), pineapple weed (Matricaria
suaveolens), common groundsel (Senecio vulgarts), burdock (Arc-
tium lappa), Silybum marianum, Centaurea melitensis, prickly let-
tuce (Lactuca scariola), mustard (Brassica campestris), also such
native weeds as Amsinckia and Escholtzia.

726 WEED FLORA OF IOWA

Fig. 549A 1

Fig. 549A IT

Fig. 549A III

Fie. 549-A. Seeds of weeds scattered with agricultural seeds. I. Dodder in
clover and alfalfa seed. II. White Sweet Clover in alfalfa seed. III.
Bitter Dock (Rumex obtusifolius) in red clover seed.

Many of these weeds have made their way into California by
way of South America. Others are indigenous and widely scat-
tered on the Pacfiic coast. The Pacific northwest has in common
with the rest of the Pacific coast many European weeds, but also
many that are indigenous to the country. Many years ago Cusick
called attention to the predominance of the Northern fireweed
(Epilobium angustifolium), which, after the removal of the forest
and the burning of the slashings, comes up in great abundance.
The writer in another connection* discussed the weeds commonly

*The Problem of Weeds in the West; Proc. Ia. Acad. Se. 15: 34.

WEED MIGRATION 727

Fie. 550. Curled Dock (Rumex crispus). .A common European weed now
occurring across the continent.
(After Chesnut, U. S. Dept. Agr.)

found in the northwest. A few of the abundant species may be
mentioned. Russian thistle (Salsola kali var. tenutfolia) is abun-
dant in the drier regions, especially east of the Cascades. In the
Puget Sound country are found such common European weeds as
Canada thistle (Cirsium arvense), bull thistle (C. lanceolatum),
batchelor’s button (Centaurea cyanus), chicory (Cichorium inty-
bus), common mustard (Brassica arvensis), mullein (Verbascum
thapsus) and also V. blattaria, and toadflax (Linaria vulgaris).
It is not uncommon to find in clearings of the forest the small
Kenilworth ivy (Linaria cymbalaria), the common pansy (Viola
tricolor), the petunia (Petunia grandiflora), the dead nettles (La-
mum amplexicaule and L. album), ox-eye daisy (Chrysanthemum
leucanthemum), hemp nettle (Galeopsis tetrahit), foxglove (Digi-
talis purpurea), European bindweed (Convolvulus arvensis). The

728 WEED FLORA OF IOWA

eats’-ear (Hypochaeris radicata) is one of the most common weeds
in lawns. There is a common belief that it was introduced from
Chile.

In the Great Basin country, especially in Utah, a large number
of the weeds are of Huropean origin. Of the most common of
these mention may be made of the brome grasses (Bromus brizae-
formis and B. tectorum), bouncing Betty (Saponaria vaccaria),
black medick (Medicago lupulina), dodders (Cuscuta arvensis and
C. epithymum), poison hemlock (Coniwm maculatum), moth mul-
lein (Verbascum blattaria), mint (Mentha viridis), Russian thistle
(Salsola kali var. tenuifolia), horehound (Marrubium vulgare),

Fie. 551. Awned Brome Grass (Bromus tectorum).. Common in the Great
Basin country and California, occasionally in Iowa.

WEED MIGRATION 729

prickly lettuce (Lactuca scariola) and storksbill (Hrodiwm cicu-
tartwm). There are also such native weeds as bee-plant (Cleome
serrulata), wild liquorice (Glycyrrhiza lepidota), the squirrel-tail
grasses (Hordeum jubatum and H. caespitosum), prickly lettuce
_(Lactuca pulchella), pine-apple weed (Matricaria suaveolens) and
prickly poppy (Argemone platyceras). In the Rocky mountain re-
gion, especially Colorado, many of the more recent introductions
are from Europe. Among these are the sweet clovers (Melilotus
alba and M. officinalis), black medick (Medicago denticulata),
purslane (Portulaca oleracea), dodder (Cuscuta arvensis and C.

2: b
Fig. 551A I Fig. 551A IL

G @
oy 92

Fig. 551A IIL : Fig. 551A IV

Fic. 551-A. Seeds scattered with agricultural seeds... I. Barnyard Grass
(Echinochloa crusgalli). 11. Medicago denticulata, common in alfalfa
seed. II. Horehound (Marrubium vulgare), a weed commonly scattered
with alfalfa seed. Common in the Great Basin country. IV. Wild Buck-
wheat or Bindweed (Polygonum convolvulus), commonly scattered with
grain seed.

(All after Hillman.)

epithymum), foxtail (Setaria viridis), storksbill (Erodiwm cicu-
tarium), Russian thistle (Salsola kali var. tenuifolia), vegetable
oyster (Tragopogon porrifolius), goat’s beard (T. pratensis) and
lamb’s quarters (Chenopodium album). A large number of native
plants have become weedy, such as marsh elder (Iva xanthifolia),

730 WEED FLORA OF IOWA

(Franseria discolor), the two annual sunflowers (Helianthus an-
nuus, H. petiolaris), small ragweed (Ambrosia artemisiaefolia),
buffalo bur (Solanum rostratum), Rocky Mountain bee plant
(Cleome serrulata), gumweed (Grindelia squarrosa) and squirrel-
tail grass (Hordewm jubatum).

Fig. 551B IIT Fig. 551B IV

Fic. 551-B. Seeds of immigrant weeds. I. Squirreltail (Hordeum jubatum) ;
widely scattered with hay and stock trains from the western plains. II.
Spinage (Spinacia oleracea) ; a common weed of the Great Basin country.
Seattered from cultivated plants. III. Russian Thistle (Salsola kali var.
tenuifolia) ; brought to Dakota with flax seed and grain seed; now scat-
tered in Iowa with alfalfa seed. IV. Winged Pigweed (Cycloma atri-
plicifolium).

(II, drawing, L. R. Collins; the others after Hillman.)

Cosmopolitan Weeds.—A great many weeds, originally, had a
very wide distribution, although many of these so-called weeds
were probably introduced by man. In many eases it is almost
impossible to tell how and whence they came to the places in
which they occur. . ;

Who can trace the immigration of such weeds as common purs-
lane, or charlock, or barnyard grass? In the first: place, these

WEED MIGRATION So tetod

plants immigrated when little was known about the species of
plants. What was said about them by the early botanical writers
was often very indefinite. In the second place, many of the early
writers did not take pains to leave statistics concerning the intro-
duction of the plants. The future records, however, will be more
accurate as the adventive plants are being recorded by a host of
botanical writers the world over. The notes in such floras as
Britton’s Manual, Robinson and Fernald-Gray’s Manual, Bentham
and Hooker’s Handbook of the British Flora, Garcke’s Flora of
Germany, Acloque’s Flora of France, Moore’s Handbook of the
Flora of New South Wales, Arcangeli’s Flora of Italy, Baron Fer-
dinand von Mueller’s Systematic Census of Australian Plants,
Grisebach’s Flora of the British West Indies, Millspaugh’s Flora
of Yucatan, Hemsley’s Botany of Central America, Urban’s papers
on the Flora of the West Indies give more or less detailed infor-
mation on introduced weeds.

Fie. 552. Crabgrass (Digitaria sanguinalis). A cosmopolitan weed.

The following weeds are more or less cosmopolitan: crab grass
(Digitaria sanguinalis), found in North and South America, Eu-
rope, Asia, Africa, Australia and New Zealand; barnyard grass
(Echinochloa crusgallt), in Europe, Asia, Africa, North and South
America and Australia; green foxtail (Setaria viridis), in Europe,

732 WEED FLORA OF IOWA

Fig. 553. Foxtail Grass (Alopecurus geniculatus). Widely distributed. Cos-
mopolitan grass.
(U. S. Dept. of Agr.)

Asia, Africa, Australia, North and South America; pigeon grass
(Setaria glauca), in Europe, Asia, Africa, North and South Amer-
ica; whorled millet (Setaria verticillata), in Europe, Asia, Africa,
North and South America; Johnson grass (Sorghum halepense),
in Europe, Asia, Australia and North America; foxtail grass
(Alopecurus genculatus), im Asia, New Zealand, Australia, North
America; hair grass (Agrostis hyemalis), in Australia, New
Zealand, North America; Bermuda grass (Cynodon dactylon), a
valuable forage plant, but, in cultivated fields, a weed, Europe,
Asia, Africa, Australia, New Zealand, North and South America;
southern spear grass (Hragrostis pilosa), Europe, Asia, Africa,
Australia, New Zealand, North and South America; crowfoot grass

WHED MIGRATION 733

(Eleusine indica), Europe, Asia, Africa, Australia, New Zealand,
North and South America; cheat (Bromus secalinus), Europe,
Asia, North America, a weed; brome grass (Bromus tectorum),
Europe, Asia, Africa, North America; soft chess (Bromus arven-
sis), Europe, Asia, Africa, North America... It is singular that
only one species of Bromus is given by Moore and Ferdinand von
Mueller, the Bromus arenarius. Reed (Phragmites communis),
though not regarded as a weed in the United States, is a cosmo-
politan plant-found in Europe, Asia, Africa, Australia, New
Zealand, Papua, North America (Canada, United States and
Mexico).

Yy
if
\
y
f \\ J
7

Fic. 554. Tumbling Mustard (Sisymbrium altissimum). Introduced with grain
in the Dakctas.
(Dewey, U. S. Dept. Agr.)

Cress (Barbarea vulgaris) occurs in Europe, Asia, Australia,
New Zealand and North America. None of the most common
North American weeds among the remaining members of the mus-

734 WEED FLORA OF IOWA

tard family occur in Australia or New Zealand, although shep-
herd’s purse (Capsella bursa-pastoris), common mustard (Brassica
arvensis), the hedge mustards (Sisymbrium officinale and S. altis-
stmum) and peppergrass (Lepidiwm apetalum) are common in
Europe and Asia.

Of the pulse family the bird’s-foot trefoil (Lotus corniculatus) —
occurs in Europe, Asia, Africa and Australia; the indigo plant
(Indigofera hirsuta) in Africa, Australia, Papua and Asia. The
absence of black medick (Medicago lupulina) and hop clover (Tri-
folium agrartum) from Australia is striking.

Of the geranium family the common European, African and
Asiatic species of storksbill (Hrodium cicutariwm) are absent in
Australia and New Zealand and the little yellow flowered sorrel
(Oxalis cormculata) is the only representative in New Zealand,
Australia and Papua. This species also occurs in Europe, Asia,
Africa and America. The only malvaceous weeds in Australia
common also to the United States are sida (Sida spinosa) and
butter-print (Abutilon theophrasti), both of tropical origin. The
former occurs in Europe, Asia, Africa, North and South America,
Australia and Papua. The pigweed (Amaranthus retroflexus) of
southern North America is common in Europe but has not reached
Australia. None of our troublesome weedy species of dock, which
are cosmopolitan, occurs in Australia. Of the smartweeds there
are two species, the water pepper (Polygonum hydropiper)
(Europe, Asia, North and South America) and slender smartweed
(P. lapathifolium) of Europe, Asia, North ‘and South America.
Silky cinquefoil (Potentilla anserina), of the rose family, is com-
mon in the west and here and there in northern Iowa; it is found
in Europe, Asia, Africa, Australia, New Zealand and North
America. Feverfew (Agrimonia striata) is found in Europe,
Africa and North America. None of our Oenotheras is cosmo-
politan; however the primrose willow (Jussiaea suffruticosa), a
sub-tropical plant, is widely distributed in Asia, Africa, America
and Papua. Very few of the Umbelliferae are cosmopolitan.
Moore and Mueller record water parsnip (Siwm latefolwm) for
New Zealand and Australia.

The Mexican Ageratum conyzoides of the sunflower family, found
in Africa, Asia, Europe, North and South America, is often weedy.
The Spanish needle (Bidens bipinnata) is found in Asia, Europe,
North and South America. The small number of plants of this
family found in Australia.and New Zealand is remarkable. None

WEED MIGRATION "735

of our plantains is of common occurrence. There is no morning-
glory.

It may be of interest to compare the noxious weeds of Ger-
many with those of the United States. Dr. A. Thaer of the Uni-
versity of Giessen in 1881 published a small book on the agricul-
tural weeds of that country listing the following: (Those printed
in small capitals are also weedy in Iowa.) Corn poppy (Papaver
rhoeas), mustard (BRASSICA ARVENSIS), charlock (RAPHANUS
RAPHANISTRUM), Canada thistle (CiRstUM ARVENSE), corn cockle
(AGROSTEMMA GITHAGO), chickweed (STELLARIA MEDIA), sheep sorrel
(Rumex acetosella), vetch (Vicia hirsuta), colt’s-foot (Tussilago
farfara), corn chamomile (Anthemis arvensis), corn marigold

Fic. 555. Cypress Spurge (Euphorbia cyparissias). Common in Europe and
waste places in Iowa. In many cases started in the vicinity of cemeteries.
(After Strasburger, Noll, Schenck and Karsten.)

(Chrysanthemum segetum), groundsel (Senecio vernalis), corn-
flower (Centaurea cyanus), sow thistle (SoNCHUS OLERACEUS),
small bindweed (CoONVOLVULUS ARVENSIS), clover dodder (CuSCUTA
EPITHYMUM), broom rape (Orobanche ramosa), garden orach

736 WEED FLORA OF IOWA

(Atriplex hortense), cock’s comb (Rhinanthus crista-galli major
and minor), smartweed (PoLYGONUM PERSICARIA), cypress spurge
( EUPHORBIA CYPARISSIAS) , meadow saffron ( Colchicum autumnale),
silky bent-grass (Agrostis spica-ventr), wild oats (AVENA FATUA),
chess (BROMUS SECATINUS), quack grass (AGROPYRON REPENS),
horse-tail (EQUISETUM ARVENSE).

L. Danger in his work on weeds and parasites of Germany, pub-
lished in 1887, divides the weeds of Germany into two classes:
A. Root weeds, B. Seed weeds.

A. Root weeds—Quack grass (Agropyron repens), reed grass
(Phragmites communis), bindweed (Convolvulus arvensis), deadly
nightshade (Atropa belladonna), goatweed (Aegopodium roda-
graria), sheep sorrel (Rumex acetosella), sour dock (R. crispus),
meadow saffron Colchicum autumnale), marsh marigold (Caltha
palustris), mint (Mentha arvensis), thistle (Cirsium arvense, C.
alteraceum, C. acaule, C. heterophyllum, C. palustre, C. lan-
ceolatum), (Carduus crispus, C. lanceolatus, C. natams), (Onopor-
don acanthium), sow thistle (Sonchus arvensis, 8. palustre, S. asper,
S. oleraceus), colt’s-foot (Tussilago farfara, T. hybrida, T. peta-
sites), yarrow (Achillea millefolium), (Leontodon autumnalis)
dandelion (Taraxacum officinale), plantain (Plantago coronopus,
P. arenaria, P. major, P. media, P. maritima, P. lanceolata), horse-
tails (Hquisetum arvense, E. palustre).

B. Seed weeds—Chess (Bromus secalinus), (Alopecurus
agrestis), wild oats (Avena fatua), (Agrostis spica-venti), darnel
(Lolium temulentum), black nightshade (Solanum nigrum), black
henbane (Hyoscyamus niger), Jimson weed (Datura stramonium),
fool’s parsley (Aethusa cynapium), hemlock (Coniwm maculatum),
cowbane (Crcuta virosa), Venus’ comb (Scandia pecten-veneris),
buckwheat (Fagopyrum esculentum), smartweed (Polygonum
persicaria), dooryard knotweed (Polygonum aviculare), corn cockle
(Agrostemma githago), buttercups (Ranunculus septentrionalis,
k. flammula, R. arvensis), nettle (Lamtum), charlock (Raphanus
raphamstrum), foxglove (Digitalis purpurea), mustard (Brassica
arvensis), mayweed (Anthemis arvensis and A. cotula), groundsel
(Senecio vulgaris), horseweed (Erigeron canadensis), field mari-
gold (Chrysanthemum segetum), Frenchweed (Galinsoga parvi-
flora), spurge (Euphorbia cyparissias), orach (Atriplex hortense),
nettles (Urtica wrens, U. dioica).

WHED MIGRATION 737

AMERICAN WEEDS INTRODUCED INTO EUROPE.

Every year more weeds are introduced into Europe from Amer-
ica; however, it is very noticeable that the more abundant of these
are from the warmer regions of America, rather than from the
colder regions. A good many of these are weeds of the open
country of North America. I have looked rather hastily through a
few of the floras of Great Britain, Italy, Austria and Germany, in
addition to a number of recent references on the adventive flora
of Europe, from which these data have been compiled.

Apple of Peru (Nicandra physaloides) Germany (Garcke).

Aster (Aster novi-belau) Italy (Arcangeli), Germany (Garcke),
France (Acloque).

Aster (Aster parviflorus) Germany (Garcke).

Aster (Aster salicifolius) Germany (Garcke).

Bug seed (Corispermum hyssopifolium) Germany (Garcke),
Italy (Arcangeli).

Bur cucumber (Sicyos anglinus) Germany (Garcke), Italy
(Areangell).

Clotbur (Xanthiwm spinosum) Italy (Arecangeli), Germany
(Garcke, Bitter, Kiefer), Austria (Neilreich), France (Acloque).

Collomia (Collomia grandiflora) Germany (Garcke).

Cone flower (Rudbeckia hirta) Germany (Garcke).

Cone flower (Rudbeckia lacimata) Germany (Garcke, Bitter;
Lehmann).

Cone flower (Lepachys pinnata) Germany (Bitter).

Kvening primrose (Oenothera sinuata) Germany (Bitter).

Fleabane (Erigeron annwus) France (Acloque), Italy (Ar-
eangeli).

Fleabane horseweed (Hrigeron canadensis) France (Acloque),
Austria (Neilreich), Germany (Garcke, Lehmann), England
(Hooker), Italy (Areangeli).

Galinsoga (Galinsoga parviflora) Italy (Arcangeli), Germany
(Garcke).

Pigweed (Amaranthus retroflexus) Italy (Arcangeli), Germany
(Garcke, Alpers), France (Acloque), Austria (Neilreich).

Goldenrod (Solidago canadensis) Germany (Garcke, Wegelin),
Austria (Neilreich).

- Goldenrod (Solidago lanceolata) Germany (Gareke), England
(Hooker).
47

738 WEED FLORA OF IOWA

Fic. 556. Goldenrod (Solidago rigida). Common in Iowa.
(Photographed by Gardner.)

Goldenrod (Solidago serotina) Italy (Arcangeli), Germany
(Garcke).

Mexican tea (Chenopodium ambrosioides) Germany (Garcke,
Alpers), Italy (Arcangeli).

Nightshade, buffalo bur (Solanum rostratum) Germany (Garcke,
Alpers).

Nightshade, buffalo bur (Solanum heterodoxum) Germany
(Garcke).

Nightshade, Three-flowered (Solanum triflorum) Germany |
(Garcke, Alpers).

Pellitory (Parietaria pennsylvanica) Germany (Garckane

Peppergrass (Lepidiwm virginicum) Germany (Garcke), France
(Tourlet)..

Phacelia (Phacelia tanacetifolia) Gemede (Garcke).

Pigweed, Tumbleweed (Amaranthus graecizans) Italy (Arean-
geli), Germany (Bitter).

Pigweed (Amaranthus retroflexus) Italy (Arecangeli), eine
(Garcke, Alpers), France (Acloque), Austria (Neilreich).

WEED MIGRATION 739

Fig. 557. Rice Cut Grass (Leersia oryzoides). Common in low grounds, Iowa;
not, however, regarded as a weed. Common in Italy.
(Lamson-Scribner, U. S. Dept. of Agr.)

740 Sat WEED FLORA OF IOWA

Pigweed, winged (Cycloloma platyphyllum) Italy (Arcangeli).

Plantain (Plantago aristata) Germany (Bitter).

Ragweed, small (Ambrosia artemisiifolia) Germany (Garcke,
Laubert).

Rice cut-grass (Leersia oryzoides) Italy (Arcangeli), Germany
(Garcke,. Buchenau), France (Acloque), Austria (Neilreich),
England (Hooker).

Sida (Sida spinosa) Germany (Alpers).

Spanish needle (Bidens bipinnata) Italy (Areangeli), Germany
(Garcke, Boute), France (Acloque).

Spanish needle (Bidens frondosa) Italy (Arcangeli).

Spanish needle (Bidens leucanthus) Germany (Garcke).

Speargerass (Hragrostis pilosa) Italy (Arcangeli), Germany
(Garcke), France (Acloque).

Speedwell (Veronica peregrina) Italy (Arcangeli), Austria
(Neilreich).

Sunflower, artichoke (Helianthus tuberosus) Italy (Areangeli),
Germany (Garcke).

Sunflower, common (Helianthus annuus) Germany (Garcke),
Austria (Neilreich).
_ Tickle grass (Panicum capillare) Germany (Alpers, Care
France, Italy (Arecangeli), Austria (Neilreich).

Tickseed (Coreopsis tinctoria) Germany (Bitter).

Waterweed (Elodea canadensis) Germany (Garcke, Scherer,
Weshoff, Bitter), England (Hooker), France (Acloque).

INDIGENOUS WEEDS COMMON TO THE NORTHERN HEMISPHERE.

In all probability a few of the weeds here listed have been intro-
duced, at any rate their origin is in doubt; some occur in Hurope
and North America only; those found in Asia are marked (As.).

Achillea millefolium (yarrow) (As.).

Alopecurus geniculatus (marsh foxtail).

Anagallis arvensis (pimpernel) (As.).

Anaphalis margaritacea (everlasting).

Atriplex patula var. hastata (orach).

Barbarea vulgaris (yellow rocket).

Bidens cernua (sticktight).

Capsella bursa-pastoris (shepherd’s purse).

Cerastiwm arvense (mouse-ear chickweed).

Convolvulus sepium (morning-glory) (As.).

WEHED MIGRATION 741

Sem

CAN

WP
UNAS

Fic. 558. Yarrow (Achillea millefolium). Common in the northern hemis-
phere.
(Drawing by Charlotte M. King.)

Cyperus esculentus (northern nut grass) (As.).
Epilobium angustifolium (fireweed) (As.).
Erigeron acris (fleabane). ©

Erysimum chewranthoides (treacle mustard).
Galwum trifidum (bedstraw) (As.).

Galium aparine (cleavers) (As.).
Gnaphalium uliginosum (cudweed).
Hierochloe borealis (holy grass)...

Juncus tenuis (wire-grass).

Lepidium apetalum (peppergrass).

Mentha arvensis (mint) (As.).

Myosurus minimus (mouse-tail).

Oxalis corniculata (field sorrel).

742 WEED FLORA OF IOWA

Plantago major (common plantain) (As.).
Polygonum aviculare (dooryard knotweed) (As.).
Polygonum hydropiper (smartweed).

Polygonum lapathifolium (smartweed).

Potentilla anserma (silvery cinquefoil).

Potentilla monspeliensis (five-finger) (As.).

Fic. 559. Holy or Vanilla Grass (Hierochloe borealis). Common in the northern
hemisphere, mountain regions. In northern Iowa.
(Lamson-Scribner, U. S. Dept. Agr.)

Prunella vulgaris (self-heal).

Radicula palustris (marsh cress) (As.).
Ranunculus cymbalaria (erowfoot).
Ranunculus pennsylvanicus (crowfoot) (As.).
Ranunculus repens (crowfoot).

Rhinanthus crista-galli (yellow rattle).

WEED MIGRATION 743

Senecio palustris (ragwort).

Stachys palustris (woundwort) (As.).

Taraxacum officinale (dandelion). This species occurs every-
where in the United States and Europe, even on the highest moun-
tains.

Fic. 560. Dandelion (Taraxacum officinale). Common in the northern hemis-
phere, across the continent.

INTRODUCTION OF SOME WEEDS INTO THE UNITED
STATES AND INTO IOWA. ©

CHENOPODIACEAEH, GOOSEFOOT FAMILY.
Russian Thistle (Salsola kali var. tenwifolia).

This plant has long been known as a troublesome weed. Henfrey,
in his work, “‘The Vegetation of Europe, its Condition and Causes,”’
published in 1852, notes its abundance in Russia, east of the Volga.

744 WEED FLORA OF IOWA

Linnaeus, the Swedish botanist, seems to have known the plant as
it occurred in eastern Europe. Prof. L. H. Dewey has given us a
good account of the introduction of this weed in the United States.*
It seems to have been first observed in Scotland, Bonhomme county,
South Dakota, in 1873 or 1874, the seed having been brought in
with flax seed. In 1877, it was reported from Yankton county;
five years later in the counties to the north and west of Bonhomme.
By 1888 it had infested many of the counties east of Missouri river
and two years later practically all of the counties of South Dakota
and southern North Dakota. About the same time it invaded

Fic. 561. Russian Thistle (Salsola kali var. tenuifolia). Common in eastern
Europe. Introduced into the Dakotas, 1873 or 1874. Now common in
northern United States, particularly in the west.

(Drawing by Charlotte M. King.)

*Bull. Div. of Bot., U. S. Dept. of Agr. 15:12. 1894.

WEED MIGRATION 745

northwestern Iowa, northeastern Nebraska and western Minnesota.
In 1898 it was reported from Colorado, Wisconsin, Illinois and
other western states. In 1894 Pammel gave the following account
of its distribution:

Prof. Dewey’s map indicates that the badly infested area extends
from the east bank of the Missouri river at Bismarck to Jamestown
and Moorehead in North Dakota; south to Sioux City, in Iowa, it
also occurs in many isolated places in Minnesota, Wisconsin, Iowa,
and at Denver, Colorado. The localities at which he found it in
Towa are Rock Rapids, Emmetsburg, Spencer and west to the
Missouri river, Council Bluffs, and on the Missouri river opposite
Nebraska City. To these we must add Edna, Ames, Little Rock
(Ball), Calumet (Louthan), Missouri Valley, Mason City, Hagle
Grove, and in all probability it occurs along our great trunk lines
across the state. Last season Mr. G. W. Carver found a small
specimen of what undoubtedly was Russian thistle along the Chi-
cago & Northwestern railroad; the place was revisited this year,
and an abundance of the weed was found. <A few days” later
Messrs. Robt. Combs and C. B. Weaver found. several localities ;
between Ames and Ontario, and Mr. Sheldon reported it in the
Ames stock yards. As to its probable early appearance in Iowa
we have reliable data. Prof. A. S. Hitchcock, an excellent ob-
server and collector, reported it from Woodbury county in 1888,
and Mr. R. I. Cratty, of Emmetsburg, reported it from Emmet
county in 1890 or 1891. It has also been sent to me from Ellsworth,
in Nobles county, Minnesota, close to the Iowa line. Mr. G. W.
Carver found great quantities of it near Chicago, at Turner Junc-
tion, and J. J. McMahon from Peatone, Illinois.

It occurred as early as 1890 in Wisconsin. The writer, in re-
cently looking over a collection of specimens made in the vicinity
of Prairie Du Chien, in 1890, found a specimen of Russian thistle.
The species was growing in considerable quantity along the sandy
embankment of the river and railroad, not far from the railway
station. It is not unlikely that it spread eastward along the Chi-
cago, Milwaukee and St. Paul railroad for considerable distance.

It now occurs in many Iowa counties, especially along railroads. .
It is one of the most abundant weeds in western Nebraska, Colo-
rado, Utah, Montana and Idaho. It is more or less sporadic in its
appearance ; some years more abundant than others. It was espe-
cially common at many points in Iowa in 1910 and 1911. Its dis-
tribution in Jowa as reported from time to time is as follows: Post-
ville, 1894 (Orr) ; Mason City and Eagle Grove, 1894 (Pammel) ;
Muscatine, 1894 (Reppert); Boone, 1895 (Carver); Ames, 1895
(Rolfs) ; Hawarden, 1895 (Pammel) ; Missouri Valley, 1897 (Pam-
mel) ; Ledges, 1898 (Pammel) ; Armstrong, 1901 (Cratty) ; Ogden,

746 WEED FLORA OF IOWA

1901 (Pammel) ; Slater, 1902 (Fawcett, Tener and Reinbott) ; Mar-
shalltown, 1902 (Pammel) ; Aurelia, 1912 (Summers) ; Sidney, 1912
(Graham).

Winged Pigweed (Cycloloma platyphyllum Moquin.).

Not. indigenous in Iowa. Des Moines, 1887 (A. 8S. Hitchcock) ;
Hamburg (A. S. Hitchcock); Muscatine, 1890; Ontario, 1892
(Burgess); Des Moines, 1894 (Carver); Cedar Rapids, 1895
(Palmer).

City Goosefoot (Chenopodium urbicum L.).

Nevada, 1880 (A. S. Hitchcock) ; lowa City, 1887 (A. S. Hitch-
cock) ; Keokuk, 1887 (A. S. Hitchcock); Muscatine, 1890 (F.
Reppert) ; Ames, 1891 (A. S. Hitchcock) ; Keokuk, 1891 (P. H.
Rolfs).

Oak-leaved Goosefoot (Chenopodium glaucum L.).

Towa City, 1889 (Hitchcock) ; Muscatine (F. Reppert).

Jerusalem Oak (Chenopodium botrys L.).
Ames, 1883; Iowa City, 1887 (A. S. Hitchcock).

Mexican Tea (Chenopodium ambrosioides L.).
Keokuk (J. C. Arthur) ; Muscatine, 1890 (F. Reppert).

Coast Blite (Chenopodium rubrum).
Keokuk, 1891 (P. H. Rolfs).

Orach (Atriplex patula L. var. hastatum Gray).

Towa City, 1887 (A. 8. Hitchcock) ; Keokuk, 1891 (P. H. Rolfs) ;
Ames, 1896, where it has now become well established; Boone, Ft.
Dodge, 1912 (L. H. Pammel) ; Storm Lake, 1912 (L. H. Pammel).
Var. littorale, Towa City, 1887, (A. S. Hitchcock).

Silvery Orach (Atriplex argentewm Nutt.).
Ames, 1895 (G. W. Carver).

Mexican Fireweed (Kochia scoparia (li.) Schrad.).

Mexican fireweed is recorded as an adventive from Europe in the
sixth edition of Gray’s Manual of Botany, 1889, by Watson and

WEED MIGRATION ~ 747

Coulter, with the statement “‘sparingly introduced in Vermont,
Ontario, and Illinois.’’ It is not recorded in the fifth edition of the
same work by Dr. Gray in 1867. In the Britton Manual, 1901,
the distribution is given as Ontario, Vermont, and northern New
York, adventive from Europe, native also of Asia. According to
the Robinson and Fernald Edition of Gray’s Manual (7th. Ed.),
1908, it had become so common becatise of its cultivation and “‘lo-
eally established as a weed’’ that the distribution was not given.
The writer saw it in abundance as a weed in Denver and Ft. Collins,
Colorado, and Salt Lake, in 1902, and in Chicago the same year. It
has been spontaneous as a weed in Ames since the year 1900. It
has been observed in Ames, Council Bluffs (1901), Sioux City
(1902), Cedar Rapids (1905), LaCrosse, Wis. (1904).. The fol-
lowing catalogue of plants lists the species: Rydberg, -Colorado,
at Fort Collins.

COMPOSITAH, SUNFLOWER FAMILY.

Prickly Lettuce (Lactuca scariola).

This species was abundant in Utah in 1898 and was observed in
many parts of California the same year, but was, however, far
less common in the east. It was first observed in central Iowa,
Ames, in 1909 and now occurs in Ft. Dodge, Boone and Des Moines,
and is rapidly spreading. It is common in dry places in the Rocky
mountains and on the Pacific coast. Robinson and Fernald state,
‘*Roadsides, railway ballast, etc., New England to Oregon, N. W.,
and Kentucky, chiefly westward, but even then less common than
the following variety (var. integrata).’’ It is common in northern
and central Ohio, Indiana and Illinois (DeKalb, Fox, Aurora,
Geneva, Chicago and Wheaton).

Prickly Lettuce (Lactuca scartola var. integrata).

Waste grounds, roadsides and fields from the Atlantic to the
Pacific, especially northward. This is the form commonly referred
to by botanists when speaking of the weed in the east. This variety
was first reported by Dr. Gray. Specimens were collected by Mr.
D. Murray in 1863 and 1864; some specimens were collected by
M. S. Bebb at Rockford, Illinois, in 1879, and about the same time
by Mr. Henry Eggert in St. Louis. In 1883 it was common in the
vicinity of Madison but had not reached La Crosse, Wisconsin.
In 1886 a few specimens were reported in the vicinity of Onalaska

748 WEED FLORA OF IOWA

near La Crosse. It was abundant in Jowa in 1886, was reported
from Eagle Grove in 1894 by Cratty, and by the same observer at
lake Okoboji in 1901. The writer observed it abundantly in
various places in Nebraska and eastern Colorado in 1894 and gave
a more definite account of its distribution and spread in a paper
in Proceedings Iowa Academy Sciences. In 1912 it was very
abundant everywhere in Iowa. The seeds are easily scattered by
the wind, which probably accounts for its wide distribution in a
comparatively short time.

Thistle (Cirsium palustre).

This European thistle is recorded as naturalized in woods, East
Andover, New Hampshire, (Holt) by Robinson and Fernald in the
7th edition of Gray’s Manual, 1908, and was reported from Iowa
in 1911 and again in 1912.

Canada Thistle (Cirsium arvense).

This well known weed is common everywhere in Europe and is
perhaps a weed of the open. Linnaeus in his Flora Lapponica
(1837) notes that it is the greatest pest of our fields. It is dis-
tributed from the Atlantic to the Pacific across the northern states
and in Canada. In Iowa it is found more particularly in the
north half of the state. The earliest floras of the state (Arthur,
Bessey, and Parry) note its occurrence in Iowa. It has occurred
in Ames for forty years. In 1889 it was noticed in many counties.
Cratty reports the species from Emmet county in 1892. At this
time it had been reported also from Howard, Adair, Chickasaw,
‘Johnson and Poweshiek counties. In 1899 it was thoroughly es-
tablished in a forest near Steamboat Rock in Hardin county.
Plants from the early introduction seldom produced seed, but seed
from the later introductions is not uncommon; thus it has been
matured in O’Brien county and in Cresco, 1892 (C. V. Johnson).
It is spreading rapidly in northern Iowa, having become much
more widely distributed in 1903 and 1506 with clover seed.

It has been reported from Johnson county, 1874 (O. G. Bab-
cock); Lawler, 1890 (P. H. Rolfs); Greenfield, 1891 (F. C.
Stewart); Corning, 1895 (A. B. Shaw); Taylor, 1895 (J. B.
Matthews) ; Maple River Junction, 1895 (L. Bernholtz) ; Farragut,
1895 (C. Collman); Marcus, 1896 (Willey); Winterset, 1896;
Barnes City, 1896 (J. W. Jones) ; Nevada, 1898 (G. C. White) ;
Steamboat Rock, 1899; Rockwell, 1901 (J.’H. Boom); Badger,

WEED MIGRATION 749

1902 (Myrhe); Audubon, 1905 (M. C. Griffith); Graettinger,
1906 (E. L. George); Clarion, 1909 (Melhus); also in Lorimer
(Lochrie) ; Blairsburg (J. M. Hall); Oelwein (J. Thompson) ;
Muscatine (F. Reppert) ; Reading (Dr. McClanahan) ; Griswold
(R. E. Pierce) ; Randall (C. & G. R. Christianson) ; Hartley (H. R.
Foblenkamp) ; Garrison (J. Grayson); Roland (E. N. Waugh) ;
Kossuth (S. A. Merrill) ; Cedar Falls (C. E. Daily) ; and Wool-
stock (A. P. Reynold).

Woolly Thistle (Cirsiwm canescens).

This plant has been reported from several states north and west
of the Mississippi. In Jowa it occurs chiefly in the northern half
of the state, having been reported by A. S. Hitchcock in 1889, as
erowing near Sioux City. Later it was reported from Sioux City
by Pammel, 1895; Armstrong (Cratty), 1897; Webster City
(McCoy), 1901; Onawa (Fletcher), 1902; Le Mars, 1902 (Wm.
Long) ; Charter Oak, 1903 (C. N. Weed) ; Pisgah (L. H. Raymond),
1903; Rolfe (J. B. Jolliffe), 1908; Lu Verne (W. F. Blumer),

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Fie. 562. Woolly Thistle (Cirsium canescens). Originally along the Missouri

and adjacent territory. Now spreading eastward. 1, head; 5, single flower;

6, achenium; 7, stamens and style; a, stigma enlarged; 8, pollen grain.
(Drawings by Charlotte M. King.)

750 WEED FLORA OF IOWA

1911; Harlan, Shelby county, Buena Vista county, and Clay
county, 1912 (Pammel); Sac county, 1912 (Lee); Storm Lake,
1912 (Rehnstron) ; Dickens, 1912 (Evans) ; Smithland, 1912 (Bar-
ber) ; Cartersville, 1912 (Connor). j

Hawkweed (Hieracium floribundum).

This weed, reported from Cutler, Maine, in 1902, now occurs in
fields from New Brunswick to eastern Maine.

Paint Brush (Hieraciwm aurantiacum).

Paint brush was cultivated as an ornamental plant in Maine in
1875 and became frequent in the New England states and New
York in the early eighties. It is now distributed from eastern
Quebee to Pennsylvania and occasionally in Iowa.

Cat’s-ear (Hypochaeris radicata) .

According to Fernald this appeared in Penzance and Wareham,
Massachusetts, in 1899; since then it has spread to other New
England localities, as New Bedford and Dartsmouth. It had been,
however, a very troublesome weed of lawns of the Pacific north-
west for some time previously. It was abundant in Portland,
-Oregon, in 1906.

Stinking Willie (Senecio jacobaea).

Fernald (1905) states that in the late 70’s a coarse yellow
flowered plant (Senecio jacobaea) appeared as a waif on ballast
at some points along Northumberland Strait in eastern New Bruns-
wick. In 1884, it had begun to spread along the local railroads
and now has reached Portland, Maine. The seventh edition of
Gray’s manual (1908) gives its distribution from Newfoundland
to New Jersey.

Barnaby’s Thistle or Knapweed (Centaurea solstitialis).

This weed was not reported in the sixth edition of Gray’s
manual (1889) nor in Britton’s manual (1901). In the seventh
edition of Gray’s manual, Robinson and Fernald state, ‘*‘ Waste
ground, eastern Massachusetts to Ontario and lowa.’’ It was re-
ported from Iowa as early as 1903, and since, a few times each
year, in alfalfa fields as follows: Paton, 1903 (Lundell) ; Maple-
ton, 1904 (Perrin) ; Moville, 1905 (Morton); Des Moines, 1907

WHED MIGRATION 751

(Wallace). J. Burtt Davy reported it from central California in
the nineties.

Marsh Elder (Iva xanthifolia).

Dr. Gray in the fifth and sixth editions of the manual gave its
distribution, ‘‘Northwest Wisconsin to Minnesota, Kansas and
westward.’’ Originally this must have been a local weed in Wis-
consin and eastern Minnesota. Upham in 1890 mentions it as one
of the most aggressive weeds of Red river, especially in waste
places. Parry includes it in his list of plants collected in the
upper Mississippi valley in 1848. It is not improbable that this
plant was brought to eastern Minnesota and Wisconsin by the early
voyagers, the Indians or the white settlers. It is a weed of the
open and cultivated soil, especially near habitations. The early
settlers in the Red river valley gave to it the name of “‘half breed
weed’’ because so commonly found near the habitations of the
half breeds who lived in that section of Minnesota, Manitoba and
Dakota. There are early records of the weed, however. Hall
mentions its occurrence near Athens, Illinois, in 1863. This was
after Hall had returned from his trip to the Rocky mountains. He
may have thrown away some of the seed, which germinated and
produced plants. It was a common plant in the Rocky mountains,
as reports of such botanists as Parry, Vasey, Hall, Fendler, M. E.
Jones, Suksdorf, Cusick, Kelsey, Brandegee, Havard, Bigelow,
(Camanche Plains, 1853) and others indicate its abundance.
Though reported from Charles City by Arthur in 1871 it has not
made much progress east of the Missouri river basin. Its dis-
tribution and date of appearance.may be seen from the following:
Boone, 1890 (Pammel) ; Keokuk, 1890 (Rolfs) ; Woodbine, Vale,
Eagle Grove, Mason City, and Carroll, 1894 (Pammel) ; Armstrong,
1897 (Cratty) ; Ogden and Slater, 1896; Hanlontown and Ames,
1902 (Pammel) ; Decatur county, 1911 (Anderson). It was a fre-
quent and abundant weed from Sioux City to Council Bluffs and
probably south to Hamburg; reported at Independence, and, in
1876, at Humboldt, by Harvey. It had been reported from Emmet
county as early as 1875, having been introduced with cattle. It
has not spread very rapidly at any of these interior points. It —
was reported in St. Paul in 1861 (T. J. Hale) and it was abundant
along the highway on a bank near La Crescent, Minnesota, in 1884.
It now occurs in Hokah, Brownsville, and other points along the
river (1910). In the early nineties it appeared in Onalaska, Wis-

752 WEED FLORA OF IOWA

Fic. 563. Marsh Elder (Iva xanthiifolia). Common in the Red River Valley,
spreading eastward.

WEED MIGRATION 753

consin (Pammel); Menominee Valley, 1888 (Runge) ; Kewaunee
county, 1889 (Wheeler, Farwell) and in Seneca, New York. It is
abundant throughout the country and common in the northwest to
Washington. It is abundant in western Iowa and is rapidly
spreading eastward, also becoming an aggressive weed from Ames
north to the Minnesota line and westward. It was reported from
Europe (Denmark, Ostenfeld) 1895.

Perennial Sow Thistle (Sonchus arvensis).

This thistle was reported by John Torrey in 1826 in the northern
and middle states. Dr. Gray in 1848 in the first edition of the
manual reported it from Massachusetts, Staten Island, and in New
Jersey ; it did not occur in Pennsylvania, or at least was not men-
tioned by Darlington. The 5th edition of Gray’s manual, 1867,
gives its distribution ‘‘roadsides, etc., New England, New York,
becoming more abundant;’’ the 7th edition (1908) says ‘‘from
Newfoundland to the Rocky mountains northward.’’ Britton
(1901) places it in the same general region and west to Salt Lake, —
Utah. The weed is not common in Iowa nor in the surrounding
states except northward in Minnesota and Dakota. It was re-
ported from Grand Junction, Iowa, in 1898 by Tomson and from
Ogden, Iowa, about 1900; the writer found it in Englewood, II-
linois, in 1886, and in northern Ohio in 1912. It has spread rapidly
in recent years in Canada, North Dakota and Minnesota, as
recorded in the agricultural press of the last two or three years.

Galinsoga or Frenchweed (Galinsoga parviflora).

Danger has given several accounts of the introduction of this
weed into Europe. The term Frenchweed seems to have been
commonly applied to this weed in Germany shortly after the French
soldiers occupied Hanover. One authority states that it was
brought from France with horse feed; it is said to have been in-
troduced into Germany about 1812. One authority states that the
weed was distributed from the Berlin Botanical Garden in the
year 1812, at any rate it was very common in Hanover in the year
1839; and has continued to spread. It may have spread from its
first introduction near Paris to other places of France about the
year 1800, although there is no definite date as to when it made its
appearance in the vicinity of Paris. This plant is native to Peru
where it was discovered by Ruiz and Pavon. about 1794, so

48

754 ' WEED FLORA OF IOWA

it must have been introduced into Europe following their descrip-
tion. In the United States the weed has become quite widely
disseminated in recent years. The writer found it abundant in
the vicinity of green-houses in the Missouri Botanical Garden in
1886, subsequently in 1896 he found it in similar situations in
Ames and about 1898 or 1899 in La Crosse, Wisconsin. The writer
has observed it at other points but always first in the vicinity of
ereen-houses. This would lead to the assumption that it probably
has been disseminated with flower seed.

Horseweed (Hrigeron canadensis).

This widely distributed weed is common everywhere in North
America and is said to have been introduced in the vicinity of
Paris in 1635, although Leunis’ Botany states ‘‘introduced in
Europe in 1500.’’ It is mentioned as one of the most common
weeds of Germany and Switzerland by Ratzeburg (1859). Treatises
by Garcke, Koch, Ratzeburg and Acloque mention it as a common
weed.

Spiny Clotbur (Xanthium spinosum).

According to Kabsch, this weed is said to have been introduced
into Germany with wool brought from Hungary. Though it
originated in ‘tropical America it has become established as far
north as Maine (Robinson and Fernald). Thurber in 1859 gave
its distribution from Massachusetts to Georgia. In 1889, it reached
Leavenworth, Kansas, and in the course of time will be found in
Towa.

Hawkweed (Senecio vernalis).

This weed was first mentioned by Rosenberg as occurring in
Switzerland in 1882. It spread to Silesia; disappeared; was re-
ported in West Prussia in 1824, in Breslau, 1835, Brandenburg,
1850, Stettin in 1860, first as a mere waif, then spread to cultivated
fields generally.

Chicory (Cichorium intybus).

Chicory was introduced into Dorchester, Massachusetts, in 1775.
Torrey records it for the northern and middle states in 1826. Gray
in 1848 stated ‘‘naturalized in the Atlantic States;’’ the 6th edition
of Gray’s Manual stated that it occurs from New England to Iowa
and Minnesota; the 7th edition adds Newfoundland and southward.
It was common in Wisconsin in 1884 and was spreading; it oc-

WEED MIGRATION 755

eurred in Colorado in 1896. Gray reports it for Santa Barbara,
California, in 1880, and since then it has become fairly common in
that state. It was reported from several localities by Crandall and
Rydberg in Colorado in 1906; reported by Webber in Nebraska.
Mr. F.. W. Paige states that this weed has been known in Ft. Dodge
since 1887. In 1906 it was spreading in Pottawattamie, Story, Sac,
Clay, and Kossuth counties, and has been reported from Westgate
(Bruce Fink), 1893; Boone (Geo. W. Carver and Pammel), 1895;
Des Moines, 1895; Corning, 1895 (Ellen Bettomer) ; well estab-
lished in Midway, 1896; Jordan, 1906 (Harriette Kellogg).

Vegetable Oyster (Tragopogon pratensis L.).

This was reported from Ames, in meadow, 1894; Iowa City,
1889; Newton, 1889 (A. 8. Hitchcock).

Fetid Marigold (Dyssodia papposa (Vent.) Hitche.).

Ackley, 1878 (B. E. Canavan); Boone, 1890; Keokuk, 1891
(P. H. Rolfs) ; Muscatine, 1891 (F. Reppert). This striking weed
has been known for some time at Ames, and was said by Hitchcock
to be frequent (Anth. Pteridophyta of Ames, p. 503). It is more
or less sporadic in its appearance, being frequent in some years,
in others not so common. It is, however, always abundant in
western lowa, which leads me to believe that the plant is not in-
digenous to central lowa, but introduced, although now occurring
in timber and along river banks.

Ox-eye Daisy (Chrysanthemum leucanthemum L.).

For a long period of years occasional specimens of this weed
have been found in the vicinity of the college, and it is an occa-
sional introduction in meadows, but except in one place some four
miles from Ames it shows no evidence of being naturalized. It has
also been reported from Muscatine (Reppert); Atlantic (S. O.
Hamill) ; Ames, 1871 (C. E. Bessey) ; Ackley, 1878 (B. E. Cana-
van); Sheldahl, 1885 (L. V. Harpel) ; Ames, 1891 (P. H. Rolfs) ;
still occurs between Ames and Gilbert, 1911, but is not spreading.

Mr. J. H. Lees reports this plant as having been introduced into
the vicinity of Cedar Falls as early as 1890 and as occurring near
LeMars in 1912.

756 WEED FLORA OF IOWA

Gumweed (Grindelia squarrosa Dunal).

Indigenous to western Iowa, rapidly spreading in contiguous
territory, and reported from Boone and Moingona, as abundant
in borders of woods along Chicago & North Western Railway in
1890 and still spreading in 1912; reported from Keokuk, 1891
(P. H. Rolfs) ; Battle Creek, 1895 (E. G. Preston) ; Osgood, 1895
(C. A. Wells); Carbonado, 1895 (John H. Smith); Smithland,
1896 (J. M. Wrapp).

Eclipta (Eclipta alba Hassk.).
Keokuk, 1877 (Geo. E. Ehinger), 1891 (P. H. Rolfs).

Sunflower (Helianthus annuus L.).

Occasional in Ames and other parts of central Iowa, but in
western Iowa indigenous and very abundant, becoming frequent
as far as Carroll (Kelley) 1900; Denison and Boone. It was re-
ported in Boone in 1871 (C. E. Bessey) ; Ames, 1882; Grinnell,
1891 (M. E. Jones) ; Keokuk, 1894 (P. H. Rolfs) ; Muscatine, 1891
(Reppert) ; and Marshalltown, 1891 (F. C. Stewart). It is not
abundant except in a few localities in central Iowa. It is an in-
troduced plant with us.

CONVOLVULACEAE, MORNING-GLORY FAMILY.

Bindweed (Convolvulus arvensis).

This weed is of long standing in the United States. It is men-
tioned by Torrey in his Compendium of ‘‘The Flora of the North-
ern and Middle States’’ in 1826, and Dr. Gray in his first edition
of his manual in 1848 gives the distribution from Massachusetts
to Pennsylvania. Darlington, in 1853, states: ‘‘This foreigner
has gradually extended itself among us—and will probably give
our farmers much trouble if they do not carefully guard against
it.’’ This certainly has been realized in many of the central and
eastern states. The statement in the seventh edition of Gray’s
manual would indicate quite general distribution in the region
embraced in this work. The fifth edition (1867) states, “‘fields
near the coast; likely to become a troublesome weed.’’ Britton
gives its distribution from Nova Scotia to Kansas (1901); South
Dakota, Parker (1903). It was abundant in St. Louis in 1886
and was reported at various times in Iowa as a troublesome weed

WEED MIGRATION 757

before 1889. Since 1887 it has been well established in Ames; it
was reported from Ladora, 1895 (John Hiltbrummer) ; Des Moines,
1896 (C. N. Page) ; Westgate, 1902 (P. H. Hinager) ; Fort Dodge,
1912 (EF. W. Paige); and very likely occurs in other places. It
was first introduced as a cultivated plant. This may become one
of the most pestiferous of our perennial weeds.

EUPHORBIACEAE, SPURGE FAMILY.
Snow-on-the-Mountain (Euphorbia marginata Pursh.).

Indigenous to western Jowa. Little Rock, Sioux City, Onaiwa,
Council Bluffs and Hawarden. Naturalized east. Iowa City, 1887
(A. 8. Hitchcock) ; Hamburg, 1888 (A. S. Hitchcock). Abundant
at Denison, 1894; Woodbine, 1894; Vale, abundant, 1894;. Missouri
Valley, Carroll, 1895, abundant (W. Newell).

GRAMINEAH, GRASS FAMILY.
Squirrel-tail Grass or Wild Barley (Hordewm jubatum L.).

This plant was made known to science by Linnaeus, from speci-
mens found in Canada. Dr. Asa Gray, in his Manual of Botany
of Northern United States in 1856, gives its distribution as
‘“marshes and moist sands of the sea shore and the northern lakes.’’
In 1868, its distribution was not extended, but Watson and Coulter,
who revised the manual (1890), add to the above ‘‘and westward.’’
In the seventh edition of Gray’s manual the distribution is given -
as ‘‘coast Labrador to New Jersey prairie and waste ground,
Ontario to Illinois, Kansas, and westward.’’ It evidently is very
generally distributed throughout the United States. At Ames,
specimens have been received from Wyoming, Colorado, Nevada,
New Mexico, Idaho, Utah, Montana, Yellowstone Park, Illinois, Ne-
braska, the Dakotas, Minnesota, Kansas and from Argentine. It
has also been reported from California, Wisconsin, Arkansas, Mis-
souri, Michigan, Indiana, Ohio, New York, New Jersey, Massa-
chusetts, Maine, Canada (in many parts), Europe (Russia), and
Siberia in Asia. A truly cosmopolitan weed. .

We are without exact data in regard to its early appearance in
Iowa, though it was probably native in portions of western and
northwestern Iowa, especially where the soil was somewhat broken
up. From answers received it would seem that this grass has been
known in parts of Iowa for over fifty years, but it is only during the
last twenty-five years that it has made much headway. Though

758 WEED FLORA OF IOWA

Fic. 564. Wild Barley (Hordeum jubatum). Originally common along the
shores of the Great Lakes, and alkali regions of the west.

possibly native, it is more than probable that this weedy grass has
come into our state from the west as well as the east. It has be-
come so thoroughly at home in many parts of lowa that no one:
would be able to say, except for the records we have, that it has
not always been indigenous.

Forty years ago this weed was mentioned by Dr. Bessey as oc-
curring in Iowa, ‘‘found along railroads, perhaps introduced,’’
being noticed at Ames especially. It undoubtedly occurred in
other parts of the state, but could not have been abundant or its
presence would have been noted. Early in 1876 Dr. J. C. Arthur
listed the plant from Iowa without locality. Prof. Halsted refers
to the weed as common, but not excluding valuable plants. He
considered it an introduced plant. One other botanist, Prof. A. S.
Hitcheock, listed the plant from Ames, and remarks: ‘‘ Waste
places; common.’’ The plant was certainly abundant about Ames
in 1889, when I came here, but it has not spread quite so alarmingly
as prickly lettuce (Lactuca scariola L.). In July, 1895, a circular
was sent out to some correspondents in every county in the state

WEED MIGRATION 759

inclosing a specimen and: requesting information in regard to its
introduction, weedy nature, diseases, etc. Replies were received
from most of the correspondents. From this information it ap-
pears that the plant has been in parts of the state many years,
and several correspondents reported it as indigenous. It has been
in Cedar Rapids for 57 years; in Carroll county, 33 years; Mason
City, 45 years; Hawkeye, 40 years; Hampton, 37 years; Jefferson,
40 years; Mount Pleasant, 36 years; Cresco, 35 years; Newton, 35
years; Unity, 35 years; Iowa City, 30 years; Shenandoah, 35 years;
Neola, over 45 years; Fort Dodge, 50 years; Dedham, 35 years;
Rossville, 45 years. It was not, however, generally distributed in
the state. But it has shown wonderful aggressive powers and now
occurs without doubt in every county in the state.

It is more than likely that in Iowa, at least, the weed has spread
from three sources: (1) Indigenous plants scattered in western
and northwestern counties. (2) From the Great Lakes, where
itis indigenous. (3) From the western plains, where it no doubt
was indigenous.

LABIATAE, MINT FAMILY.

Lance-leaved Sage (Salvia lanceaefolia Poir.).

Indigenous to western Iowa. Council Bluffs, Fremont county,
Missouri Valley, Ames, 1890 (F. A. Sirrine) ; Muscatine, 1890 (F.
Reppert) ; Des Moines, 1895, well established; Harlan, 1912 (Pam-
mel).

LEHGUMINOSAH, PULSE FAMILY.

Sweet Clover (Melilotus officinalis).

Torrey, in 1826, gave the habitat of sweet clover as ‘‘ wet mead-
ows.’’ Gray, in 1848, reports it for the east; it apparently had not
reached Pennsylvania, since it is not recorded by Darlington. This
plant was observed in the vicinity of St. Louis, Missouri, in 1887,
and in Humboldt, Iowa, in 1892. In 1894 it was abundant in
eastern Colorado, Fort Collins, Denver, and other localities, indi-
cating naturalization for a considerable length of time. As yet
it is not common in central Iowa, though it was abundant in Sioux
City and Council Bluffs as early as 1895. It had already been re-
ported from Iowa City by Hitchcock in 1889, and from Muscatine
by Reppert in 1891. L. H. Pammel found it in Dakota City in
1896, and R. I. Cratty reported it from Emmet county in 1903; it
is rather abundant at present in Scott county.

760 WEED FLORA OF IOWA

White Sweet Clover (Melilotus alba Lam.).

This plant is not named by Torrey in 1826, but in 1840 its dis-
tribution was given by Torrey and Gray as ‘‘Rich soils, along rivers,
New York and New England. Introduced.’’ In Flora Cestriea,
Darlington says that it appears in gardens and lots, having been
naturalized from Europe. In 1853 he says that ‘‘this coarse hard
stemmed plant has been partially cultivated by some amateur
farmers; but it is not likely to supersede the herbs now in general
use as food for cattle.’’ In the first edition of Gray’s Manual its
distribution is given as ‘‘adventitious from Europe.’’ The same
distribution is given in the sixth edition. In the seventh edition
we read, ‘‘Roadsides, etc., common. (Nat. from Europe).’’ In
Iowa, while it is found along the roadsides everywhere, the dates
given with the following localities may indicate to some extent how
it has spread: Vicinity of Ames, 1886; Iowa City, 1887 (A. S.
Hitcheock) ; Emmet county, 1888 (Cratty) ; Ames, found frequent-
ly, 1890 (J. F. Rolfs and F. C. Stewart) ; Muscatine, 1891 (Rep-
pert) ; Turin and Onawa, 1894 (L. H. Pammel) ; Webster City and
Postville, 1894; Alden, 1895 (Stevens); abundant in Moingona,
Boone, Slater, Council Bluffs and Sioux City, 1895 (Pammel) ; Da-
kota City, 1896 (Pammel) ; Kossuth county, 1897 (R. I. Cratty) ;
Ogden, 1898; Carroll, 1898; Marshalltown and Des Moines, 1902
(Pammel). It was introduced into the vicinity of La Crosse, Wis-
consin, as a forage plant in 1878 or 1879.

Wild Liquorice (Glycyrrhiza lepidota Nutt.).

This weed was reported from Grand Junction, 1872 (C. E. Bes-
sey), and Harrison county, 1875 (Rev. Burgess); Ontario, 1886
(Hitchcock) ; Ames, 1889 (Hitchcock) ; Greenfield, 1891 (F. C.
Stewart). Spreading near Greenfield, undoubtedly introduced, in-
digenous to western and northwestern Iowa. It was spreading at
Little Rock, 1893 (C. R. Ball) ; Hull, 1895 (W. Newell) ; Logan,
1895; Council Bluffs, LeMars, 1896 (W. J. Newell) ; Lenox, 1896
(Gilby ABI Ne

Stone Clover (Z'rifolium arvense L.).
Collected by Professor Bessey in 1871, has not been found since.
Hop Clover (Trifolium agrarium L.).

Reported by Hitchock from Ames in 1886, has not been found
since.

WEED MIGRATION 761

Low Hop Clover (Trifolium procumbens L.).

Ames, 1882 (Hitchcock) ; Iowa City, 1884 (Hitchcock). It is now
frequent in Ames; also in northeastern Iowa, in Waukon, Decorah
and Dubuque, also in Clayton county.

Dakota Vetch (Hosackia purshiana Benth.).

Indigenous to the loess of Iowa along Missouri river. Sioux City,
naturalized. Boone, 1895 (G. W. Carver).

Black medick (Medicago lupulina).

Reported by Dr. John Torrey in 1826 as occurring in fields, also
by Dr. Gray in 1848 and Dr. Darlington in 1853. In the fifth
edition of Gray’s manual it was said to be ‘‘adventitious from Eu-
rope in waste places.’’ Britton, in 1901, states, ‘‘In fields and
waste places, common only throughout our area.’’ It was found in
Kossuth county, Iowa, in 1898; at Ames, 1871 (C..E. Bessey) ;
1898 (A. F. Sample and E. R. Hodson). Mr. F. W. Paige records
having seen it in Fort Dodge about 1900.

MALVACEAE, MALLOW FAMILY.

Shoo-fly (Hibiscus trionum).

Reported in the first edition of Gray’s manual in 1848. It is
also mentioned by Darlington in 1853 as occurring in gardens and
lots. The fifth edition of Gray’s manual states, ‘‘advanced from
Europe.’’ The seventh edition gives ‘‘a wide distribution, culti- ~

Fig. 565. Shoo-fly (Hibiscus trionum). This weed was widely distributed as
an ornamental plant.
(Drawing by Charlotte M. King.)

762 WEED FLORA OF IOWA

vated and waste ground, rather local.’’ This weed was common in
Texas in 1888 and local in a good many counties in Iowa in 1909.
In Iowa it has been reported as follows: Fayette, 1894 (Bruce
Fink) ; Winterset, 1895 (G. W. Carver); Waterloo, 1904 (B. D.
Roberts).

Indian Mailow or Rutterprint (Abutilon theophrastt).

This weed is not mentioned by Torrey, 1826, nor in the first
edition of Gray’s manual, 1848, but is recorded by Darlington in
1853. This foreign weed is becoming rather troublesome in culti-
vated grounds in Iowa. Jt was more or less common in the vicinity
of LaCrosse in 1883; was abundant in Iowa in 1886.

ONAGRACEAE, EVENING PRIMROSE FAMILY.
Evening Primrose (Oenothera biennis).

This American weed became a settler of Padua, Italy, in 1612.
Since then it has spread to every country of Europe and is recog-
nized as one of the most common weeds of the continent, although
it does not have as good a means of dissemination as many other
weeds, like the dandelion, thistle, bull thistle, ete. The small
seeds of this plant may and perhaps frequently do cling to hoofs
of animals and with mud may be carried by the feet of birds.

PLANTAGINACEAE, PLANTAIN FAMILY.
Buckhorn (Plantago lanceolata).

This weed seems to have been pretty well established in the
eastern states, when the first edition of Gray’s manual was pub-
lished in 1848, as it was reported as common. John Torrey, in a
compendium of the Flora of the Northern and Middle States, pub-
lished in 1826, describes the weed, indicating that it was evidently
pretty well established. Darlington, in his Flora Cestrica, 1853,
states, “‘this weed is extensively naturalized and more abundant
than welcome in upland pastures.’’ In the fifth edition of Gray’s
manual the distribution is given as ‘‘dry fields, common eastward,”’
1867. The seventh edition indicates a wider distribution, and
Britton in 1901 indicates a distribution from New Brunswick to
northwest territory, Florida and Canada. It was observed in the
vicinity of LaCrosse, Wisconsin, in 1892, and as early as 1874 in
Ames (C. E. Peterson). F. W. Paige records it from Fort Dodge

WEED MIGRATION 763

in 1899. It is reported as quite common now in many counties of
the state, being generally distributed with clover seed. It has also
been reported in Ames, 1890 (F. A. Sirrine and L. H. Pammel) ;
1894 (G. W. Carver) ; Hartley, 1905 (W. B. Elliott) ; Audubon,
1906 (A. H. Edwards) ; Ames, 1909 (M. Clapper) ; Fayette (Bruce
Fink) ; Maynard (A. F. Crawford).

PHYTOLACCACEAE, POKEWEED FAMILY.
Pokeweed (Phytolacca decandra L.).

Grinnell, 1889 (A. S. Hitchcock) ; Muscatine, 1891 (F. Reppert) ;
Ames, 1894 (lL. H. Pammel). <A waif; not established.

POLYGONACEHAH, BUCKWHHAT FAMILY.
Patience Dock (Rumex patientia L.).

Boone (G. W. Carver). Established. Escaped from cultivation.

Prince’s Feather (Polygonum orientale L.).

Muscatine, 1890 (F. pee) Onawa, 1894; Clinton, 1897
(Pammel).

PORTULACACEHAH, PURSLANE FAMILY.
Purslane (Portulaca oleracea).

Cultivated in Massachusetts in 1672 and since has spread to
every part of the United States, appearing like an indigenous
plant. It is likewise common in Germany, Holland, England,
France and other European countries and in Australia. <A cos-
mopolitan weed.

764

WEED FLORA OF IOWA

66.

Purslane (Portulaca oleracea). At first cultivated in. the United
States for greens; now appearing like an indigenous plant.
(Vasey, U. S. Dept. Agr.)

WEHED. MIGRATION 765

SOLANACHAH, POTATO FAMILY.
Horse Nettle (Solanum carolinense).

This weed is a most troublesome species in southern Iowa. It
was reported in the southeastern part of the state as early as
1876 and has gradually moved northward until at present it
is well scattered over the state. In Nebraska, Aughey had found
it in 1875, and it was reported in Weeping Water by T. A. Will-
lams in 1889; in Illinois it had been known for half a century near
Peoria (Brendel); Port Byron, 1894 (Pammel); South Chicago
(Higbee and Raddin); Delaware, Neweastle county, 1860 (Tat-
nall) ; Pennsylvania, 1823 (Humphrey Marshall and Beck) ; West-
chester, 1853 (Darlington) ; New Jersey, 1887 (Halsted and Brit-
ton); New York, 1888; Buffalo, 1864 (Clinton); Cincinnati,

Fic. 567. Horse Nettle (Solanum carolinense). Originally a weed of the
southern states; rapidly spreading northward. a, general aspect of plant;
b, flower; d, seeds; ec, seed enlarged. : :
(After Dewey, U. S. Dept. Agr.)

766 WEED FLORA OF IOWA

Ohio, 1889 (James) ; central and southern Ohio, 1860 (Newberry) ;
Grand Rapids, Michigan, 1886 (Crozier); Topeka, Kansas, 1883
(Popenoe) ; Connecticut, Iowa, Illinois and Michigan. Within
fifty years this perennial weed has extended its range northward
in Iowa over 150 miles. This has been possible because of its
deep roots. Darlington, in his Flora Cestrica, states that it was
introduced by the late Humphrey Marshall into his botanical gar-
den at Marshalltown.

It was reported from Nashville, Tennessee, in 1877 by Gattinger ;
St. Louis, 1879, by Eggert, and abundant in western Missouri in
1886 (S. M. Tracy) ; Rhode Island, 1887 (J. L. Bennett) ; Wiscon-
sin, Watertown, 1887 (lL. H. Pammel) ; Indiana, Dune Park, 1890
(Higbee and Raddin, Bolley, Arthur) ; Illinois, 1891 (Brendel).
In Iowa it was reported from Emmet county, 1875 (Cratty) ; south-
eastern Iowa, 1876; Fremont county and Council Bluffs, 1883 (Ar-
thur) ; Ames, 1886 (Halsted) ; Agency, 1888 (Mrs. Richman) ; Car-
roll county, 1890 (T. T. Rutledge) ; Grand Junction, 1890 (Pam-
mel) ; Polk City and Mt. Pleasant, 1891 (L. H. Pammel and J. H.
Mills) ; Fontanelle, 1892; Denison, 1893 (J. Rollins) ; Corning, 1893
(W. L. Abbey) ; Iowa City, 1893 (Fitzpatrick) ; Springdale, 1894;
Plattesville, 1894 (Studley) ; Postville, 1894 (Orr) ; Mt. Ayr, Guth-
rie Center and Story county, 1894 (Sale, Ashton and Pammel) ;
Des Moines, 1895 (Carver); Decatur county and Des Moines
county, 1896 (Fitzpatrick) ; Webster City, 1897 (Garber) ; Shel-
dahl, 1898 (Pammel); Yorkshire, 1899 (Stokes) ; Dallas Center,
1902 (C. B. Royer) ; Mondamin, 1903 (A. Spooner) ; Cooper, 1903
(Squires) ; Afton, 1904 (Geo. Williams) ; Audubon, 1905 (J. N.
Eskech) ; Keota, 1905 (Klein); Lidderdale, 1907 (Mrs. Sander-
son); Reinbeck, 1907 (Fred Wilcox); La Porte, 1908 (R. S.
Meath) ; Algona, 1912 (A. Hutchinson) ; Collins, 1912 (J. Leon-
ard) ; Brandon, 1912 (Roster) ; Whitten, 1912 (Parrish) ; Ontario,
1884 (Fletcher) ; Germany, Mulhausen, 1893 (Scherer Schorler) ;
Denmark, 1895 (Ostenfeld).

Buffalo Bur (Solanum rostratum).

Has been reported frequently to me during the last few years.
The number of specimens sent from Jowa correspondents during
the season 1911 and 1912 was numerous, indicating a rapid spread
in many different parts of the state. It has always been a native
to the plains, finding a congenial home in the buffalo wallows.
It was reported by Hartweg in 1837 as being seen north of the

WEED MIGRATION 767

city of Mexico; by Bexar in Texas in 1828, in Rock Creek by
Fendler in 1847, and in El Paso in 1849; and by Geyer from
Pierre, South Dakota, in 1839. Nearly all of the early collectors,
as Rothrock, Parry, Fendler, Geyer, Hayden, Brandegee, Palmer,
mention this weed. It is generally believed to have become rapidly
diffused in Texas after 1865.

Jimson Weed (Datura stramonium).

Found everywhere in Jowa and in many parts of the United
States from the Atlantic to the Pacific. Common in eastern North
America for more than seventy-five years. It is mentioned by
Darlington, 1847, and Gray, 1848, states that it is a well known
weed. The date of its appearance in Europe is not given by Ratze-
burg, Kabsch notes that the thorn apple was introduced from India
by gypsies. The plant is native to India where its poisonous prop-
erties were long known. The 5th and 6th editions of Gray’s
Manual indicate a wide distribution in eastern North America. It
was common in western Wisconsin in 1881. Cratty states that it
was rare in Emmet county, Iowa, in 1881.

UMBELLIFERAE, CARROT FAMILY.

Wild Carrot (Daucus carota L.).

This was reported by Dr. Torrey as occurring in fields in the
northern and middle states in 1826. Dr. Gray records it as common
in 1848; Darlington, in 1857, states that ‘‘this foreigner is ex-
tensively naturalized and becoming more troublesome from the
culpable negligence of our farmers.’’ In his 5th edition, Dr. Gray,
in 1867, states ‘‘advanced from Europe.’’ In the 7th edition, 1908,
Robinson and Fernald state ‘‘fields and waste places, a pernicious
weed’’ indicating a general distribution. Britton, 1901, states
‘‘common throughout our area’’ and the writer knew this weed in
western Wisconsin, in 1880. In some places it was pretty well
naturalized. Occasional specimens were found by the writer in
1889, in Iowa. It had previously been reported by Halsted and
Arthur. It began to spread quite rapidly in 1904. ¥. W. Paige
reports it from Ft. Dodge in 1909. It is now reported quite fre-
quently from different places in the state. The following are a
few of the localities: Greenfield, 1891 (F. C. Stewart) ; Earlham,
1903 (J. Long) ; Carrolton, 1904 (E. C. Schreiber) ; Zearing, 1904
(E. E. Sparrow) ; Hawarden, 1905 (C. §. McCarty); Hartley,
1905 (W. B. Elliott); Panora, 1906 (L. J. Hooper); Marshall

768 WEED FLORA OF IOWA

~

Fic. 568. Carrot (Daucus carota). Common in the east. Probably first spread
from the cultivated carrot.

county, 1906 (W. R. Moninger) ; Whiting, 1907 (W. S. Whiting) ;
Allerton, 1907 (J. H. Duncan) ; Lamoni, 1907 (T. L. Naftsger) ;
Blackhawk county, 1907 (Pammel) ; Ames, 1909 (J. R. Campbell) ;
Polk county, 1910 (Pammel); Rippey, 1910 (Osborn) ; Dumont,
1910 (Titus); Libertyville, 1911 (Armstrong); Bedford, 1911
(Spacht); Glidden, 1912 (Walters); Kelley and Ledges, 1912
(Pammel).

Poison Hemlock (Coniwm maculatum).

This weed was reported by Dr. John Torrey in 1826 as occurring
on roadsides. It is mentioned by Dr. Gray in 1848 as occurring in
waste places. Britton in 1901 records it from Quebec to Michigan
and Indiana, California, and Mexico. Robinson and Fernald in
the 7th edition of Gray’s Manual indicate ‘‘to Pennsylvania,’’ the
same distribution that Britton gives. It is not, however, common

WEED MIGRATION 769

in the Mississippi valley. It was reported from Pottawattamie
county, Iowa, in 1909 and it was abundant in Salt Lake City,
Utah, in 1908 where it evidently had been naturalized for some
time. It was abundant in places in the Sacramento Valley in 1912
indicating naturalization for some time. Brewer and Watson in
Botany of California (1876) state ‘‘Sparingly naturalized.’’

49

CHAPTER X.

MEDICINAL WEEDS OF IOWA

HARRIETTE S. KELLOGG

CHAPTER xX.

MEDICINAL WEEDS OF IOWA.

In the United States, the raising of drug plants has never re-.
eeived the commercial attention that has been devoted to this
branch of agriculture abroad. As a result, we are importing
regularly for the drug trade thousands of pounds of dried plants
that might be raised in this country. Among them are many
weeds, as, quack grass and mustard that, to us, are pests to be
eradicated as quickly as possible. Not that it would be wise to
devote good agricultural land to raising medicinal weeds but as
by-products these are of value. The word ‘‘weed’’ is used ad-
visedly ; for, while many of our vegetable drugs come from plants
which in this country are not weeds, it is undoubtedly true that
many drug plants are noxious weeds in the country in which they
were first applied medicinally. This is illustrated by such weeds
as quack grass, the mustards, the docks, tansy, and dandelion, all
of which are official in the U. S. P.

As early as the days of Dioscorides the physician was the
herbalist, and his knowledge of the active principles of plants was
his stock in trade. Among semi-civilized and barbarous peoples
the same thing is true today.

While very many of the plants formerly considered medicinal
are at present discredited, a sufficient number remains to make
raising drug plants a profitable industry. ;

The literature of medical botany, if we include the ‘‘Herballs’’
is quite voluminous. In Germany, in 1787, Schoepf published the
‘“Materia medica americana, potissimum regni vegetabilis’’ in
which he listed three hundred and sixty medicinal plants which he
had collected among the American Indians; but he stated that
there were actually over seven hundred in use. Between 1817 and
1821 Jacob Bigelow published three volumes of the ‘‘ American
Medical Botany; being a collection of the native medical plants
of the U. 8.’’ in which he listed fifty plants, each illustrated by
colored plates. William Barton, about the same time, published
““Vegetable materia medica of the U. S.; or medical botany contain-
ing a botanical, general, and medical history of medicinal plants

)

ie]
{

774 WEED FLORA OF IOWA

indigenous to the United States,’’ in which fifty plants were de-
seribed and illustrated. The high price of these books, however,
necessarily limited their distribution.

In Rafinesque’s ‘‘Medical Flora,’’ published in 1828 and 1830,
one hundred and five plants are named as being native North
American plants. Among those listed are such weeds as mayweed,
butterfly weed, wormseed, wild hemlock, cowbane, thorn-apple,
fleabane, boneset, Joe-Pye weed and mullein.

The most complete work of recent years is Millspaugh’s American
Medicinal Plants in which he describes and illustrates with colored
plates 180 medicinal plants native in the United States and recog-
nized by homeopathic physicians as of therapeutic value. He also
adds to each description, the active principles of the plant in ques-
tion, the method of preparation and the physiological action of the
drugs derived therefrom. In addition to the one hundred and
eighty plants fully described, he mentions hundreds of others that
are known to the profession but are not native to the United
States, making in all so satisfactory a treatise that for many years
it must remain our most reliable source of information in this line.
In Dr. Pammel’s Manual of Poisonous Plants, many medicinal
weeds not of a poisonous nature are listed among the economic
plants.

The United States Department of Agriculture has issued a num-
ber of bulletins containing references to medicinal weeds, which
are listed in the bibliography at the end of the volume.

Many plants not listed as official in the United States Phar-
macopceia have, nevertheless, value as commercial products. Such,
fer instance, is true of the wormseed plant which, although not
recognized in our Pharmacopeia, brings from 6 to 8 cents per
pound in the drug market.

Quack grass (Agropyron repens) is the only weed of the grass
family that is official in the U. S. P. A fiuid extract from the
rhizome of this plant sold under the name of dog grass or triticum
is a remedy in kidney and bladder troubles.

The roots of various docks of the Iowa species are official. Bitter
dock (Rumez obtusifolius) and yellow dock (R. crispus) are rated
at 2 to 8 cents per pound and form the basis of various blood
purifiers. The leaves of sheep sorrel (R. acetosella) while not
official, are of market value.

MEDICINAL WEEDS OF IOWA 775

Fie. 569. Quack Grass (Agropyron repens). The root-stock used for bladder
trouble.
(Drawing by Charlotte M. King.)

The entire herb of water pepper (Polygonum hydropiper) when
decanted with alcohol forms a valuable diuretic, but is not recog-
nized in the Pharmacopeia.

The entire leafy part of the American wormseed (Chenopodium
ambrosioides) is valued for its anthelmintic properties. Oil from
the fruit is official and sells for $1.50 per pound.

776 WEED FLORA OF IOWA

Of the Phytolaccaceae, pokeweed (Phytolacca decandra) has long
been considered of medicinal value. The berries, collected when
mature, are rated at 5 cents per pound; the roots at 2 to 5 cents;
although not official they are the basis of remedies for various
diseases of the skin and blood, especially in allaying rheumatism.

In the order Caryophyllaceae is the corn-cockle (Agrostemma
githago), the powdered seeds of which are the basis of a remedy
used to cleanse the blood in certain skin diseases.

Chickweed (Stellarta media) formerly had some reputation as
an alterative but is now used very seldom.

Among the Cruciferae are several weeds that are recognized as
medicinal. The most important are the mustards, the seeds of
which are official and sell at 3 to 6 cents per pound. Both the black
mustard (Brassica nigra) and the white mustard (B. alba) are col-
lected for this purpose and are used principally in making plasters
and poultices but occasionally are administered in cases of dys-
pepsia. They are emetic when given in large doses.

The shepherd’s purse (Capsella bursa-pastoris) is not omen
At one time it was considered of value as a tonic, astringent, and
antiscorbutie but has fallen into disuse except when occasionally
apphed as an astringent in hemorrhages.

Among the Malvaceae is a dooryard weed, common mallow (Malva
rotundifolia), the whole plant of which is sometimes applied locally
as a poultice or internally as a demulcent.

A decoction of the dried plant of the evening primrose (Oenoth-

era biennis), a member of the Onagraceae, is a remedy in eases of
infantile eruptions, spasmodic asthma and bladder trouble.
“An introduced weed of the Leguminosae is noted; the yellow
sweet clover (Melilotus officinalis), the seeds of which boiled with
lard are sometimes made into a salve which is applied to ulcers
and open indolent sores, the remedy proving efficacious.

Among the Umbelliferae are the caraway (Carum carvi), the root
of which is sometimes ground into a poultice and the fruit and
leaves of which are diuretic and stimulant; the poison hemlock
(Conmium maculatum), the root of which is deadly poisonous, al-
though the unripe fruit, dried and preserved, is official, selling at
8 cents per pound, and the leaves, though not official, are sometimes
applied in eases of rheumatism, neuralgia or asthma to sooth the
nerves; and the water hemlock (Cicuta maculata), sometimes sub-
stituted for cowbane.

MEDICINAL WEEDS OF IOWA ie

Two of the Milkweeds (Asclepias incarnata and A. syriaca) are
listed as medicinal, an extract from the root alone being used.
This is a diaphoretic and was formerly applied in acute pulmonary
and bronchial affections and in rheumatism. Although at present
it has fallen somewhat into disrepute, it is sometimes given in cases
of dropsy.

A tincture from the whole plant of bindweed (Convolwulus
arvensis), of the family Convoluulaceae, is sometimes used as a
diuretic or gentle laxative.

The leaves and root of one of the Boraginaceae, hound’s tongue
(Cynoglossum officinale), are both medicinal, the latter being some-
what narcotic. The leaves were at one time used as a styptie.

Of the Verbenaceae we find records of the use of the root and
green parts of vervain (Verbena hastata) which were substituted
occasionally for boneset in fevers and agues. They are emetic and
expectorant.

The Labiate, self-heal (Prunella vulgaris), is an astringent but
by no means is the universal curative agent that its name would
suggest.

Catnip (Nepeta cataria) no longer official, nevertheless is rated
at 2 to 8 cents per pound for leaves and flowering tops, the coarse
stems being rejected. A decoction from these parts is a mild stimu-
lant and tonic, being rather quieting in effect.

Motherwort (Leonurus cardiaca) has similar properties.

The family Solanaceae is very important medicinally, as it fur-
nishes at least twenty drugs to the trade, of which the most im-
portant is belladonna. Of the Iowa weeds Jimson (Datura stra-
monvum) is the best known. The leaves ‘and seeds are official, the
former being rated at 214 to 8 cents and the latter at 3 to 7 cents
per pound. The leaves are applied in cases of asthma and the
seeds in spasmodic diseases affecting the respiratory tract. Datura
tatula is sometimes used in the same manner.

The black nightshade (Solanum nigrum) is especially valuable as
a resolvent but its use is no longer prevalent. In some parts of
Iowa the bruised leaves are considered an unfailing remedy in cases,
of ivy poisoning.

The root leaves and berries of horse nettle (S. carolinense) are.
mentioned by Alice Henkel as being medicinal though not official. |

Of the Scrophulariaceae, the cosmopolitan mullein weed. (Ver-
bascum thapsus) possesses considerable market value although it is
not recognized by the U. 8. P. as official. The dried leaves retail

778 WEED FLORA OF IOWA

at 214 to 5 cents and the flowers at 25 to 75 cents per pound. A
tincture from these is a recognized remedy in coughs and catarrh.
It quiets nervous irritation and relieves inflammation.

The uses of the plantains (Plantago) are various. The fresh
leaves are sometimes applied to wounds or chronic sores. .The
seeds steeped in milk form a remedy used in checking hemorrhages
from mucous surfaces and in dysentery. Almost every part of the
plant at some time has been recorded as medicinal. The fibers from
the leaves were thought to be an unfailing remedy for toothache,
the fiber, however, being placed in the ear on the side of the tooth
affected rather than about the tooth itself. Plantain is also an
antidote to snake bites. A decoction of the root was sometimes ad-
ministered in cases of intermittent fever.

In short it would seem possible for one to have quite a complete
medical dispensary in his own dooryard without care or expense.

The family Compositae undoubtedly contains a larger number of
medicinal genera than any other plant family.

A decoction made from the whole herb of yarrow (Achillea
millefolium) is a bladder medicine and is administered sometimes
in cases of hemorrhage or catarrh. The ragweed (Ambrosia ar-
temrsiaéfolia) is used in similar cases. The mayweed (Anthemis
cotula) furnishes a bitter stimulant and tonic in aid of digestion.
From the leaves may be made a fermentation which relieves pain
and inflammation, sprains and bruises; none of the last three named
is official.

The burdock (Arctium lappa), however, is recognized in the
U.S. P. Its fresh root gathered in autumn retails at 3 to 8 cents
and seeds at 5 to 10 cents per pound. These are both useful in
preparations against blood ‘and skin diseases. The leaves are some-
times applied externally as cooling poultices.

An infusion of the root of chicory (Cichorium intybus) is some-
times offered to increase the appetite and to aid digestion. A decoc-
tion from fireweed (Erechtites hieracifolia) is an alterative and is
applied in cases of dysentery. The oil of horseweed (Erigeron
canadense) is official, the herb being rated at 6 to 8 cents per pound.
The plant has been known locally as ‘‘blood staneh’’ and, as the
name implies, was used in arresting hemorrhages and bleeding from
wounds.

According to Millspaugh this use of the plants is practiced today
among the North American Indians. The oil only is official. The
various local names of Eupatorium perfoliatum, boneset, feverwort,

MEDICINAL WEEDS OF IOWA 779

Fic. 570. Burdock (Arctium lappa). Formerly used as blood purifier.
(Vasey, U. S. Dept. Agr.)

780 WEED FLORA OF IOWA

or agueweed, indicate the uses of the plant. It is tonic, diaphoretic,
emetic, or cathartic according to the size of the dose administered ;
the root of the white snakeroot (H#. urticaefoltwm) is also of com-
mercial importance, being rated at 2 to 8 cents per pound. The
Joe-Pye weed (HE. purpureuwm) has uses somewhat similar to the
preceding but is also a diuretic and is valuable in cases of jaundice,
dropsy, rheumatism or gout.

The leaves and flowering tops of the scaly grindelia (Grindelia
squarrosa) are the basis of a remedy against asthma and are also
sometimes made into a poultice to apply in cases of ivy poisoning.
The sneezeweed (Heleniuwm autwmnale) is a tonic and diaphoretic;
the powdered flowers are sometimes snuffed to relieve affections of
the nasal passages. The wild lettuce (Lactuca canadensis), once
considered a substitute for opium, is an anodyne, a diaphoretie,
and a diuretic, and is applied principally in nervous complaints.
Tansy (Tanacetum vulgare) is official in the U. S. P., the leaves
and flowering tops being rated at 3 to 6 cents per pound. It is a
well known but poisonous vermifuge.

The root of the dandelion (Taraxacum officinale), collected in
autumn, is official, selling at 4 to 6 cents per pound. A decoction
from this is a tonic in cases of dyspepsia and diseases of the liver.
A hair tonic is also made from it.

Undoubtedly this list could be greatly extended were it possible
to obtain information in regard to all cases of home use of native
drug plants. Unfortunately few written records are obtainable
and one is obliged to depend largely on tradition handed down by
word of mouth.

There is undeniably an opening in Jowa for raising and market-
ing medicinal plants and a few words in this line may not be out
of place at this point.

For the profitable marketing of drug plants it is necessary that
the plants be suitably prepared, that is, that they be thoroughly
cleaned and well cured. To be cleaned they must be freed from
all foreign substances, whether dirt, sand, insects, or fragments of
other plants; when cured properly, they have been picked at the
right season, and have been dried so as to retain so far as possible
their characteristic color. If the leafy part is sought for the trade,
the plant should be cut when in flower or before seeds have formed,
then dried in gentle heat (not higher than 125° F.) so as to lose as
little as possible of the volatile principle. In some plants, as cow-
bane, the unripe fruit, well dried and preserved, has value officially,

MEDICINAL WEEDS OF IOWA 781

Lut of mustard on the other hand, ripe seeds, only, are official.
The dried leaves of the catnip have market value but no longer
are recognized as official, The roots of the dandelion collected in
the autumn are listed in the U. S. P.; the rhizome of quack grass
is marketable. In short, if one is to realize any financial profit
from his fields of weeds, he must be able to recognize absolutely the
weed in question, for poisonous herbs sometimes closely resemble
innocuous weeds and a mistake in identification may result. serious-
ly; he must also know what part of each plant is salable, when it
must be collected, whether in the ripe or immature state, and in
what form it is preferred by the trade. It is not an occupation to
be followed by the careless or ignorant worker. Ignorance is no
excuse for offering to the trade a deadly herb in mistake for its
harmless relative. When the life of the patient is sacrificed as a
result of such a mistake the old saying, that ‘‘if it kills it is poi-
sonous, if it cures it is the right herb,’’ will hardly suffice as an
excuse. '

For the careful gardener, however, who is willing to wait for his
herbs to mature one year, two years, or, as with ginseng, seven
years, the occupation of growing drug plants offers many induce-
ments.

CHAPTER XI.

PHENOLOGY OF WEEDS

CHARLOTTE M. KING

CHAPTER XI.

PHENOLOGY OF WEEDS.

Several species of weedy plants bloom very early in the spring,
responding promptly to a comparatively limited amount of light
and warmth; others come to bloom after the growing season is
more advanced; while a number blossom throughout the season, or
from spring until fall.

The time of bloom is, in each species, related to its definite
physiological constant of warmth, sunshine and moisture. Warm,
sunshiny weather in the early part of the season will hasten the
time of bloom, as cold, cloudy weather will retard it. There is a
difference of about two weeks between the blooming date of plants
of northern and southern parts of Iowa.

The season of a plant’s activity is related in part to the hardiness
it has developed, and to the climatic conditions of the geographical
region selected by it, as most favorable to its existence.

It is vigor and tenacity as well as wide seed distribution which
contribute to the troublesome character of the plants which we eall
weeds.

It is indicated by the accompanying table, as known also by com-
mon experience, that the rain, warmth and sunshine received at
the arrival of midsummer produce greatest bloom of weedy plants
for the season in both number and kinds; and since weeds quickly
mature, it is apparent that the harvest of weed seeds steadily in-
ereases from that time until fall.

The crucifers are among our earlier blooming weeds, as the
winter annuals, shepherd’s purse and peppergrass; the legumes
and umbellifers are at their full growth about midsummer; the
plantains begin in May, the polygonums in June; whilst com-
posites are usually blooming throughout the latter part of the
season.

Grasses distribute their blossoming-time throughout the summer
from May until October; vanilla grass and blue grass appear in
May, orchard grass, quack grass, needle grasy and timothy in June,
crab grass, fescue grass, and rye grasses about July, Bouteloua in
August, blue-stem and drop-seed grasses in September.

50

786 WEED FLORA OF IOWA

Many plants, either annual or perennial, which have a recog-
nized weedy character, have a prolonged period of bloom and seed-
ing, thus maintaining a vigorous hold.

Common cosmopolitan weeds, belonging to various orders, have
often remarkable perennation, as in case of the dandelion, shep-
herd’s purse and chickweed; these weeds begin bloom in earliest
spring and are also more resistant to frost than are other weeds.

The period of time required for maturing fruit after blooming
varies in different species; a comparatively short time is needed
in case of most weeds, especially the late blooming ones.

The dormant period required for a seed before germination will
take place differs with varieties, and with individual seeds of the
same variety. In seeds requiring a period of rest, this delay may
be a matter of days, weeks, or years; therefore there is a distribu-
tion for seeds through time as well as through space. Many seeds
germinate immediately if conditions are favorable. Many young
plants must be lost by this autumnal vegetating, in case of seed-
lings overtaken by frost before they can bear seeds or establish
roots; but the hardy habit of the winter annual, the biennial and
perennial, protects for the most part such young plants after fall
germination.

Quack grass has a erop of seedlings of the same season as the
ripening of seed; this is true also of wild carrot, burdock, thistles,
horse nettle and ribgrass, all of which being biennial or perennial
persist throughout the winter.

The freezing and thawing of winter facilitates germination of
weed seeds in the spring; and very early one may note, in the loca-
tion of the parent of last season, as soon as the soil grows warm
enough, many flourishing young colonies of seedlings, such as
spurge, oxalis, pigweed and smartweed crowding each other for
foothold. The culturist is greatly influenced by considerations of
blooming-time, seed-time, and time of seed-germination in his ef-
forts to control and to exterminate weeds.

PHENOLOGY OF WEEDS

BLOOMING PERIOD OF COMMON WEEDS

Stellaria media A. Chickweed. 3... ..05.606- ccc sc es
Capsella bursa-pastoris A. Shepherd’s purse........
Medicago lupulina A. Yellow trefoil...............
Ozalis corniculata A. & P. Lady’s sorrel............
Taraxacum officinale P. Dandelion...............
Nepeta hederacea P. Ground ivy..........0. syaietoletele
Barbarea vulgaris B. Yellow rocket.............0.:
Cynoglossum boreale B. Hound’s tongue...........
Plantago ianceolata P. Buckhorn................+-
Ranunculus abortivus B. Small-flowered buttercup.
Ranunculus septentrionalis P. Buttercup...........
Rumecz altissimus P. Smooth dock................
Taraxacum erythrospermum P. Small-flowered dan-

GCUTO MI I ere retepew elec eel ctl ee aia/ aise wis ak aval shete. abalaversia er ece ge
Allium canadense A. & P. Wild garlic..............
Asclepias speciosa P. Showy milkweed............
Brassica arvensis A. Wild mustard ..............2.
Bromus tectorum A. Downy brome grass..........
COMENRCORUIB = (CALAWAY Cisse so oe clelaleielevanicls cleleinciere
Cerastium viscosum A. & P. Mouse-ear chickweed..
Convolvulus arvensis P. European morning-glory...
Convolvulus sepium P. Wild morning-glory........
Datura tatula A. Purple thorn-apple...............
Huphorbia marginata A. Snow-on-the-mountain.....
Hurphonbia presi A. Spurzse j.csc.scecce ssc ese cee
Glycyrrhiza lepidota P. Wild liquorice............
Hierochloe odorata P. Vanilla grass...........ce20.%
Hordeum pusillum A. Small squirrel-tail grass.....
Lepidium apetalum A. Apetalous peppergrass......
Lepidium virginicum A. Wild peppergrass........
Lithospermum arvense A. Corn gromwell..........
Lolium italicum B. or P. Italian rye-grass.........
Malwa rotundifolia P. Common mallow...........
Oxybaphus nyctagineus P. Wild four-o’clock........
Plantago major P. Door-yard plantain.............
Plantago purshii A. Pursh’s plantain.............-
Potentilla anserina P. Silverweed...........cccceeee
Radicula palustris A. or B. Marsh cress........--
Rhus toxicodendron P. Poison ivy.........scccees
Rudbeckia hirta B. Black-eyed Susan..............
_ Rumez acetosella P. Sheep sorrel..... Sono oGaguDoOo
Sisymbrium officinale A. Hedge mustard..........
Solanum carolinense P. Horse nettle............--
Solanum rostratum A. Buffalo-bur................
Sonchus oleraceus A. Sow thistle...........¢--002
Trifolium procumbens A. Hop clover..............2-
Verbena bracteosa P. Bracted verbena............
Veronica peregrina A. Speedwell......... a Nett
WAGED SOUG IND MGIONS CADE RE SCHOO SBOE O REE oon

A. Annual.
B. Biennial.
P. Perennial.

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788 WEED FLORA OF IOWA

BLOOMING PERIOD OF COMMON WEEDS—CoONTINUED.

Acalypha virginica A. Three-seeded mercury......
Amaranthus graecizans A. Tumbleweed...........
Amaranthus blitoides A. Spreading pigweed.....
Anthemis cotwia A. Mayweed................-+----
Apocynum cannabinum P. Dogbane................
Asclepias syriaca P. Milkweed.....................
Berteroa incanga A. or BP. Berteroa........+-cess+e
: Brassica nigra A, Black mustard........2.c.-+se5-
ETONLUSISCOULIUUS PAE CNEAEMEE EEE ees ool eee

CHEER WOON MONGKAG, 12. Sel ..55560600dccocossoscac
Chenopodium album A. Lamb’s quarter............
icita (maciiatale Cowbane... 445-22 ee ee. eee

Cirsium undulatum B. Wavy-leaved thistle.........
Crotalaria sagittalis A. Rattle-box.................
Cycloloma atriplicifolium A. Winged pigweed......
Datura stramonium A. Jimson weed..............
DOUCUSECOROLAME NVA ACALELOLEE EEE eee eee eee eee

Hrigeron ramosus A. Branched fleabane............
Euphorbia maculata Spotted-leaved spurge
Geummicanadenseca es -AVenst nee eee eee eee

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Hordeum jubatum A. or B. Squirrel-tail............
Hypericum perforatum P. St. John’s-wort..........
Lactuca canadensis A. or B. Wild lettuce..........
Lactuca pulchetla P. Blue lettuce..................
Lappula virginiana A. Beggar’s lice................
Leonurus cardiaca P. Mother-wort................
Lygodesmia juncea P. Lygodesmia................
Melanthium virginicum P. Bunch flower...........
Melilotus alba B. White sweet clover..............
Oenothera biennis B. Evening primrose....... eat
Parietaria pennsylvanica A. Pellitory..............
IROSHOUER STMGG. 1, WAS. 65 56danascccoccocconc
Plantago rugelii P. Rugel’s plantain...............
Polanisia trachysperma A. Polanisia...............
Polygonum aviculare A. Dooryard knotgrags.......
Polygonum hydropiperoides P. Mild water pepper. .
Polygonum lapathifolium A. Slender smartweed....

Hleusine-imdica A. Goose-27rass. ......-.....-++cs..- |

Eragrostis megastachya A. Candy-grass............
LOO CHEK EOMUOKUPOS 12, WORM GChIRBS 4 44 5553.05c50s6d008s55-
Silene antirrhina A. Sleepy catchfly...............
TRVGSDINOLUCTS 6 ASE enniviGless eae eee
Uriica vonacilisvemNetulent er. pee eee eee
Conringia orientalis A. Hare’s-ear mustard.........
Polygonum persicaria A. Lady’s thumb............
Poriuiaca oleracea Ae Pursiane. 24 ce eee See aoe
Radicula armoracia P. Horseradish................
Raphinus sativus A.) or be Radish yess eee
UMeELAChISpUSHe AGT] Cdudocke nett ee ee

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PHHNOLOGY OF WEEDS

BLOOMING PERIOD OF COMMON WEEDS—CONTINUED.

789

Rumesxz obtusifolius P. Bitter dock.................
Saponaria vaccaria A. Cow-herb............02e000:
SUEGISDANOSGPAL EE PIGKys STG cdavciyee ais steleice sfoicheinie © 6 sec
Sisymobrium altissimum A. or B. Tall hedge mustard.
Stachys palustris P. Woundwort...................
Teucrium canadense P. Germander................
LiVOULUSHUCEEESLTUS As CAItRODeaccis cecce oes sees. «
Verbascum thapsus B. Mullein....................
Verbena hastata P. Blue vervain..................
Bromus hordeaceus A. Soft chess.................-
Agrostemma githago A. Corn cockle..............
Verbena stricta P. Hoary vervain................
Atripler patula A. Orach......5..... cece ee eee eee
Acnida tuberculata A. Water hemp.................
ANC GRD, OGTR IND WRG POEs oe Sone Meo emoia Gao Nabene
Ambrosia artemistifolia A. Small ragweed..........
Ambrosia trifida A. Large ragweed................
AGREKIUHTO: UDINE 18%, IBibiroloc ey ses puloiniao ooo obo dodeUs
Bidens cernua A. Sticktight.:.....................
Bidens discoidea A. Sticktight.....................
Bidens frondosa A. Sticktight......................
Chenopodium hybridum A.-Maple-leaved goosefoot. .
Cichorium intybus PB. Chicory.$/.00...............-.
Cirsium discolor B. Field thistle...................
Cirsium ioense B. Iowa Thistle....:.............--
Cirsium lanceolatum B. Bull anise. Bs pe een Gee ee aie
Cleome serrulata A. Stinking clover...........---.

Cuscuta arvensis A. Field dodder...................
Digitaria humifusa A. Smooth crab grass..........
Dyssodia papposa A. Fetid marigold................
Hragrostis pilosa A. Pilose eragrostis..............
Hrechtites hieracifolia A. Fireweed..............
EHupatorium urticwefolium P. White snakeroot.....
Gaurarbiennis Bs; Gaunaes sss aacisss os sclass okies clas

Ipomoea hederacea A. Wild morning- glory As eats mise
Iva xanthifolia A. Poverty weed......5............
Kochia scoparia A. Kochia.....22.8.......-.0000--
ECU WEEE IZ. RATS) FARIS Goon dua oe cdapeenas
Melilotus officinalis A. er B. Yellow sweet clover..
Mentha spicata P Spearmint. .::.5:52.....2.+...<-
Physalis subglabrata P. Smoothish ground cherry. .
Polygonum convolvulus A. Black bindweed........
Polygonum erectum A. Erect knotweed.............
Polygonum hydropiver A. Water pepper...........
Polygonum muhlenbergii P. Tanweed..............

Polygonum pennsylvanicum A. Pennsylvania smart-

WiC metre tate eee ara tater Syacal Li coat ope hares MT ae Toye rap) S76 al ane
Polygonum ramosissimum A. Branching knotweed. .
Potentilla monspeliensis B. or P. Five-finger........
Salsola kali var. tenwifolia A. Russian thistle.....
Scrophuloria marylandica P. Simpson’s honey plant.
Setaria glauca A. Yellow foxtail.:.................

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790 WEED FLORA OF IOWA

BLOOMING PERIOD OF COMMON WEEDS—CoNCLUDED.

Setaria verticillata A. Whorled foxtail............--
Setaria viridis A, Green foxtail.............-ceeee-
Silene noctiflora A. Night-flowering catchfly..... ele
Solanum nigrum A. Night-shade.........cecececcee
Sonchus arvensis P. Field thistle............-.eee.
Saponaria officinalis P. Bouncing Bet.........+e.-
Stipa spartea P. Needle grass...........+..eseeoes
Strophostyies helwola A. Wild pea..........-eeceeee
Symphoricarpos orbiculata P. Indian currant.......
T.ANGCELUN VULG ATS Wes Mam siyievetst-lereielelele ele /cleie isi) <0
Lactuca scariola A. Prickly lettuce................
Hibiscus trionum A. Shoo-fly.................-..-.
Urtica dioica P. Stinging nettle..............ceeee0e

Vernonia fasciculata P. Iron-weed............ceceee

Abutilon theophrasti A. Velvet leaf...........
Amaranthus retroflecus A. Tumbling pigweed

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Aristida dichotoma A. Poverty grasS..........--ee0.
Artemisia biennis B. Wormwood.........-..-+-eeee

Artemisia ludoviciana P. Western mugwort
Aster muttifloris A. Many-flowered aster
Aster sdlicifovius A. Willow-leaved aster
Bidens aristosa A. or B. Sticktight.......
Cenchrus tribuloides A. Sandbur........
Chenopodium ambrosioides A. Mexican tea
Cirsium altissimum B. Tall thistle.......
Cirsium \canescens B. Woolly thistle......
Cyperus esculentus P. Northern nut grass
Dalea alopecuroides A. Foxtail dalea.....

Digitaria sanguinalis A. Crab grass...... ‘Shia euantaval eres

Echinochloa crusgalli A. Barnyard grass

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Helianthus grosseserratus P. Wild prairie sunflower.
Helianthus maximiliam P. Maxmilian’s sunflower. .
Helenium antumnale P. Sneezeweed...........220.

Muhlenbergia mexicana P,. Mexican dropseed

Muhitenbergia racemosa P. Dropseed grass
Solidago canadensis P. Canada goldenrod

Solidago rigida P. Stiff goldenrod.................

Solidago serotina P. Goldenrod...........

Panicum capillare A. Hair grass..............e.e-

Sporobolus neglectus A. Small rush grass.

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Sporobulus vaginiflorus A. Sheathed rush grass....

Xanthium canadense A. Cocklebur...............e-
Aanthium spinosum A. Spined cocklebur

Helianthus tuberosus P. Artichoke......

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CHAPTER XII.

WEED AND SEED LAWS

L. H. PAMMEL

CHAPTER XII.

PURE SEED AND WEED LAWS.

Many states of the United States have weed and seed laws and
similar laws are on the statute books of the principal agricultural
-eountries of the world. Long, who in ‘‘Common Weeds of the
Farm and Garden’’ has summarized the legislation, states, in Ap-
pendix III, that the laws are quite stringent in Australia, and in
‘the South African Colonies; that the only laws requiring the de-
struction of weeds in the British Islands are in Ireland and the
‘Isle of Man; that no laws or regulations are in force in Great
Britain although there is an Adulteration and Seeds Act.

Canada has a good general seed law; Manitoba has a noxious
weed act passed in 1906 which included common wild mustard,
Canada thistle, perennial sow thistle, wild oats, ‘‘stink-weed’’ or
penny cress, and false flax. The law provides that owners and
occupants of land shall be compelled to cut down, or destroy weeds,
to prevent seeding.

In Ontario the law provides that every occupier must cut down
all Canada thistles, ox-eye daisies, wild oats, ragweed, burdock and
‘all other noxious weeds to which the act may be extended by
‘municipal law to prevent the ripening of seed, provided it does
not destroy the growing grain.

The law of the Northwest Territories is similar to that of
‘Manitoba, excepting that inspectors are appointed who have the
power to act in the case of the occupier’s default. It is further
provided that threshing machines shall be cleaned before being re-
moved from one place to another. .

The law of Quebec includes daisies, wild endive, chicory, celan-
dine and wild mustards as weeds.

In Saskatchewan the Noxious Weed Ordinance schedules nine-
teen species including six species of mustard and three of thistles.
‘This province also provides for the appointment of weed inspectors.

The province of Alberta, Act of 1907 amended in 1908, mentions
22 noxious weeds. Inspectors are also appointed. The sale of
-seed containing 5 per 1,000 noxious weed seeds is forbidden and
the germinating power of all weed seed must be destroyed before

794 ee WEED FLORA OF IOWA

cleanings, etc., can be removed from any premises. Threshing ma-
chines must be thoroughly cleaned before being removed to another
place.

WEED LEGISLATION.

Various states have legislated in regard to certain weeds as
follows: Arizona on cockleburs and sunflowers; California on
Canada thistles and any and all weeds that are spread by the
wind; Connecticut on Canada thistle and wild carrot; Delaware,
Canada thistle; Illinois, Canada thistle on highways, cockleburs
and all weeds before maturity; Iowa, Canada thistle, cocklebur,
burdock, curled dock, smooth dock, wild parsnip, quack grass, vel-
vet weed, horse nettle, Russian thistle and shoo-fly; Indiana, Can-
ada thistle; Kansas, on highways, cockleburs, Rocky Mountain sand-
burs, burdocks, sunflower, and such other weeds as may be in-
jurious to the best interests of the farming community ; Kentucky,
Canada thistle; Maryland, Canada thistle; Michigan, to remove
noxious weeds on highways, Canada thistle, milkweed (Asclepias
syriaca) ; Minnesota, weeds, in three groups: first group, wild mus-
tard, wild oats, cocklebur, burdock, tumble mustard, second group,
Canada thistle, ox-eye daisy and quack grass, third group, French
weed; a section prohibits the spread of weeds from empty freight
cars; the following weeds must be destroyed on highways: Russian
thistle, Canada thistle or other thistles, burdock, ox-eye daisy, wild
mustard, snap dragon or toad flax, cocklebur, sow thistle, sour
dock, yellow dock and other noxious weeds; Missouri, Canada
thistle; Nebraska, Canada thistle; New Jersey, Canada thistle;
New York, Canada thistle and other noxious weeds along canals;
North Dakota, Canada thistle, cocklebur, mustard, wild oats,
French weed, Russian thistle; Ohio, brush briers, thistles or other
noxious weeds, Canada thistle, wild parsnip, sweet clover, wild
carrots, teasel, burdock, cockleburs; Oregon, dagger cocklebur,
Canada thistle; Pennsylvania, Canada thistle; South Dakota,
Russian thistle, Canada thistle, and cocklebur; Vermont, all thistles
and noxious weeds; Washington, Canada thistles; in West Virginia,
the county court may offer reasonable bounties or rewards for birds
of prey or weeds; Wisconsin, Canada thistle, burdock, ox-eye
daisy, toad flax, cocklebur, sow thistle, sour dock, and yellow dock,
mustard, wild parsnip, sweet clover, and Russian thistle.

Many states have passed supplementary legislation. Many other
countries besides those mentioned here have rather stringent laws

WEED AND SEED LAWS 795

on the extermination of weeds. There are laws in France and
Germany but most of the European countries appear to have no
legislation on the destruction of weeds.
- Denmark awards prizes to members of societies for weedless
fields. In most countries and most states of the United States the
laws are flagrantly violated. In the Canadian Provinces, where
weed commissioners are appointed, they seem to have remedied
this defect.

A few years ago these laws were compiled by Dewey.* The
present Iowa law is as follows:

IOWA.
SENATE FILE NO. 136.

AN ACT TO PROVIDE FOR THE DESTRUCTION OF NOXIOUS WEEDS AND
OTHER WEEDS UPON LANDS, HIGHWAYS AND OTHER PLACES; PRE-
SCRIBING: PENALTIES FOR THE VIOLATION THEREOF ; ASSESSING THE
COSTS AND EXPENSES OF THE DESTRUCTION OF THE SAME TO THE
LANDS AND OWNERS THEREOF ; AND PROVIDING FUNDS WITH WHICH
TO DESTROY THE SAME, AND REPEALING ALL OF CHAPTER NINETY-
SIx (96) OF THE ACTS OF THE THIRTY-THIRD GENERAL ASSEMBLY
RELATING TO WEEDS UPON LANDS AND HIGHWAYS.

Be tt Enacted by the General Assembly of the State of Iowa:

Section 1. It shall be the duty of each owner, occupant, person,
company or corporation in control of any lands within the state of
Jowa, whether the same shall consist of improved or unimproved
lands, town or city lots, lands used for highways, railway right of
way or depot grounds, lands in which the public has an easement
for road, street or other right of way, or lands used for any other
purpose whatsoever, to cut, burn, or otherwise entirely destroy all
noxious weeds as defined in section two (2) hereof at such times in
each year and in such manner as shall prevent the said weeds from
blooming or coming to maturity, and to keep the said lands free
from such growths of other weeds as shall render the streets or
highways adjoining the same unsafe for public travel or shall in-
terfere in any manner with the proper construction or repair of the
said streets or highways, and shall cause to be cut, near the surface,
all weeds on the Streets or highways adjoining said lands between
the fifteenth day of July and the fifteenth day of August of each
year. But nothing herein shall prevent the land owner from har-
" *Bull. U. S. Dept. Agr. Div. Bot. 17:60.

796 WEED FLORA OF IOWA

vesting the grass grown upon the roads along his land in proper
season.

See. 2. The following weeds are hereby declared to be noxious
weeds; namely, quack grass (Agropyron repens), Canada thistle
(Cirsium arvense), cocklebur (Xanthium canadense), wild mustard
(Brassica arvensis), sour or curled dock (Rumex crispus), smooth
dock (Rumez altissimus), buckhorn or ribbed plantain (Plantago
lanceolata), wild parsnip (Pastinaca sativa), horse nettle (Solanum
carolinense), velvet weed or button weed (Abutilon theophrastt),
burdock (Arctium lappa), shoo-fly (Hibiscus trionwm), wild carrot
(Daucus carota) and Russian thistle (Salsola kali L. var. tenui-
folia).

See. 3. If any such owner, occupant, person, company or corpor-
ation in control of any such land shall fail or neglect to do the
things necessary to prevent the said noxious weeds on any such land
from blooming or coming to maturity, or shall permit weeds thereon
contrary to the provisions of section one (1) hereof, or if it shall
appear that there is danger that any such noxious weeds on any
such land may mature, then upon their own motion or upon com-
plaint made to any member thereof, it shall be the duty of the board
of trustees of the township in which such land lies or to which such
land may be adjacent and within the same county, or of the town
council or board of commissioners if within the limits of an incor-
porated town or city, to make investigation of such condition or
complaint, and if it appears that there is danger that any such nox-
lous weeds may mature or that weeds thereon render or are about
to render the streets or highways adjoining the land unsafe for pub-
le travel or interfere or are about to interfere in any manner with
the proper construction or repair of the said streets or highways,
the said board of trustees, town council or commissioners, as the
case may be, shall make an order fixing the time within which the
weeds shall be prevented from maturing seed or the said weeds
shall be destroyed, prescribing the manner of their destruction, and
shall forthwith give notice in writing of the said order personally
to the owner of the land upon which the same exist if service of
such notice can be made within the township in which such land
is situated, and if it can not be so served, then by mailing said no-
tice by registered mail to the owner at his last known address, and
also by giving a copy of the notice to the person, company or cor-
poration in the apparent control or occupancy of the said land,
whose duty it shall also be to mail said notice to the owner, and

WEED AND SEED LAWS 797

if the order so made is not substantially complied with by the time
fixed in the order and after reasonable notice as herein provided,
then it shall be the duty of the board of trustees, town council or
commissioners, as the case may be, forthwith to cause said order to
be fully performed, and the expense of the same, including the
costs of serving said notice and the special meetings of the board
of trustees, town council or commissioners, if any were required,
shall be advanced out of the township road fund, or town or city
general fund, as the case may be; or if the said fund shall be in-
sufficient therefor, the town council, commissioners, or the board
of trustees may borrow the money necessary to advance the same
by issuing warrants of a like amount upon the road fund, or upon
the town or city general fund, and at any meeting of the board
they shall assess all of the same against the said land and the owner
thereof by a special tax which shall be certified and collected to-
gether with interest and penalty after due in the same manner as
road taxes unpaid and shall be collected by the county treasurer
and when collected shall be paid into the fund upon which said
warrants were drawn. Before making said assessment, ten days’
notice shall be given such owner of the time and place of meeting
of the trustees, council or commissioners, which notice shall also
contain a statement of the work done and the expense thereof with
costs, and shall be given in the same manner as originally given to
owners as hereinbefore provided. At said time and place such
owner may appear with the same rights given by law before boards
of review upon increase in assessments.

See. 4. It shall be the duty of the board of trustees of each town-
ship to consider the conditions of all lands and highways within the
township and outside of incorporated towns and cities as to noxious
weeds, and the town councils and commissions shall have the same
duties with reference to lands within their respective towns or
cities, and on complaint made to them or on their own motion, when-
ever it may appear that any of such lands within their jurisdiction
are infested with noxious weeds or other weeds, whether about to
bloom and mature or not, they shall order their destruction before
a date to be fixed in the said notice and prescribe the manner in
which the destruction shall be accomplished, notice of which order
shall be given as provided in section three (3) hereof, and if the
said order shall not be complied with the board may proceed to
cause the said order to be performed and shall certify the expense
thereof and it shall be paid and assessed to the lands upon which

798 WEED FLORA OF IOWA

the same shall have been destroyed and to the owners or owner
thereof and be collected in the same manner as is provided for the
expense of proceeding under section three (3) hereof.

Sec. 5. It shall be the duty of all officers directly responsible for
the care of public highways to make complaint to the proper town-
ship trustees or town councils or commissions, as the case may be,
whenever it shall appear that the provisions of section one (1)
hereof may not be complied with in time to prevent the blooming
and maturing of noxious weeds or the unlawful growth of weeds,
whether in the streets or highways for which they are responsible
or upon lands adjacent to the same.

Sec. 6. All of the provisions of this section relating to the duty

of the owner of the lands to prevent the blooming and maturing of
noxious weeds thereon and to destroy such growths of other weeds
thereon as may interfere with the use of highways shall apply also
to cities and towns and the proper officers there as to all streets,
highways and lands of any kind within their borders the fee of
which shall rest in the public.
“Sec. 7. It shall be the duty of the township clerk between the
first and fifteenth days of May of each year to post in two conspic-
uous places in each school district of the township a notice calling
attention to the weed law of the state of Iowa and giving a list of
the noxious weeds contained therein and notifying the property
owners to meet the requirements of the law.

Sec. 8. It shall be the duty of the township clerk between the
fifteenth and thirteenth days of October of each year to make a re-
port to the board of supervisors of the county in which this town-
ship is situated as to the presence and location of noxious weeds
that have been reported or found within the township and the steps
taken to bring about the destruction thereof, a copy of which report
shall be forwarded to the board of supervisors to be kept on file
and a copy of same to be forwarded by them to the secretary of the
Iowa department of agriculture not later than the first day of De-
cember following.

Sec. 9. Any township trustee or road officer or other officer
who neglects or fails to perform the duties incumbent upon him
under the provisions of this act shall be guilty of a misdemeanor
and shall be punished by a fine not exceeding one hundred dollars
($100.00). :

Sec. 10. Chapter ninety-six (96) of the acts of the Thirty-third
General Assembly is hereby repealed.

WHED AND SEED LAWS 799

See. 11. This act being deemed of immediate importance shall
take effect and be in full force after its publication in the Register
and Leader and the Des Moines Capital, newspapers published in
Des Moines, Iowa.*

Approved April 23, A. D. 1913, and became effective by publi-
eation May 1, 1913.

The law which was in force until repealed by the above act is as
follows:

Section 1. Land owners or tenants to destroy weeds--when.—
It shall be the duty of every person, firm or corporation owning,
occupying or controlling lands, town and city lots, land used as
right of way, depot grounds or for other purposes to cut, burn or
otherwise entirely. destroy all weeds of the kinds mentioned in .
section two (2) hereof at such times in each year and in such
manner as shall prevent the said weeds from blooming or coming
to maturity.

Section 2. Noxious weeds.——The following weeds are hereby
declared to be noxious weeds, namely, quack grass (Agropyron
repens), Canada thistle (Cirsium arvense), cocklebur (Xanthwm
canadense), wild mustard (Brassica arvensis), sour or curled dock
(Rumex crispus), smooth dock (Rumex altissimus), buckhorn or
ribbed plantain (Plantago lanceolata), and wild parsnip (Pastinaca
sativa), horse nettle (Solanum carolinense), and velvet weed or
button weed (Abutilon theophrasti) and burdock (Arctium lappa).

Section 8. Destruction on highways—neglect or refusal to de-
stroy—tlIt shall be the duty of the township trustees or other
officers responsible for the care of public highways in each town-
ship or county in this state to destroy or cause to be destroyed all
noxious weeds mentioned in section two (2) hereof or unnecessary
brush on the highways in such a manner as to effectually prevent
the production of their seeds or their propagation in any other
manner, to warn out labor or to employ labor for this purpose in
the same manner as for repairs to the highways, and for neglect
or failure to perform this work they shall be subjected to the
penalties in this act. If any occupant of lands adjacent to the
public highways neglect or refuse to destroy the noxious weeds -
upon his land, or shall fail to prevent the said noxious weeds from
blooming or coming to maturity, when such weeds are likely to
be the means of infesting the public highway, or upon complaint
of any land owner to the township trustees that his lands have
been or are likely to be infested by weeds from the lands of an-

800 WEED FLORA OF IOWA

other including railway right of way, the trustees shall make an
investigation of such condition or complaint and if the same ap-
‘pears to be well founded they shall make an order fixing the time
within which the weeds shall be prevented from maturing seed,
and an order that within one year such noxious weeds shall be
permanently destroyed, and prescribing the manner of their de-
struction and shall forthwith give notice to the occupant of the
lands where the noxious weeds exist, and if he shall neglect to
obey such order within the time so ordered the trustees may cause
such noxious weeds to be prevented from maturing seeds or may
cause such noxious weeds to be permanently destroyed and the
cost of the work shall be recovered from the owner by a special
tax to be certified by the township clerk in the same manner as
other road tax not paid.

Section 4. Road funds may be expended—The destruction of
noxious weeds in the public highway and other public places is
hereby made a part of the road work of the township trustees and
the county supervisors and they shall have authority to expend
road funds for the destruction of weeds.

Section 5. Property tax—The law as it appears in section
fifteen hundred and twenty-eight (1528) of the supplement to the
code, 1907, is hereby amended as follows, namely: By inserting
after the comma in the eighth line thereof the following words:
“‘and for the destruction of noxious weeds in public highways and
other public places,’’ and by striking out the word ‘‘four’’ in the
tenth line of said section and inserting the word ‘‘six’’ in lieu
thereof.

Section 6. School of instruction—Between November and the
succeeding April of each year the county supervisors shall eall a
meeting of the township trustees and the road supervisors of the
county to consider the best methods of road work and weed de-
struction, and in the public interest may secure the services of
experts to give instruction in road building and weed destruction.
For such attendance the same compensation shall be allowed to
‘the trustees and road supervisors and the county supervisors as
is allowed by law for other services, to be paid as other expenses.
The expenses of experts herein provided for may be paid from
the county road fund.

Section 7. Cutting of weeds on highways.—lIt shall be the duty
of township trustees and other officers directly responsible for the
eare of public highways to cause to be cut near the surface all

WHED AND SEED LAWS 801

weeds on the public highways in their respective districts at such
times and in such manner as to prevent seeds from maturing:

Section 8. Penalty—Any person, firm or corporation violating
any of the provisions of this.act, or any township trustees, in-
spector or other officer who neglects or fails to perform the duties
incumbent on him under the provisions of this act, shall be guilty
of a misdemeanor and shall be punished by a fine not exceeding
one hundred dollars ($100.00).

Section 9. Repeal.—The law as it appears in sections fifteen
hundred and sixty-two (1562), fifteen hundred sixty-two-a (1562-a)
and fifteen hundred sixty-three (1563) of the supplement to the
eode, 1907, and sections fifteen hundred and sixty-four (1564) and
fifteen hundred and sixty-five (1565) and section five thousand
and twenty-four (5024) of the code are hereby repealed.

Approved April 21, A. D. 1909.

Hon. C. R. Brenton and the writer framed a bill with the aid of
Robert Hunter, an attorney in Des Moines, which would meet all
requirement. This provided for weed inspectors. The bill was in-
troduced into the Senate by Mr. McColl and in the house by Mr.
Brady; however this bill failed to pass. As the subject is so im-
portant and is likely to come up again at a future session of the
Legislature, I insert the bill.

A BILL

FOR AN ACT TO AMEND CHAPTER NINETY-SIX (96) OF THE ACTS OF THE
| THIRTY-THIRD (33) GENERAL ASSEMBLY, AND TO CREATE THE OFFICE
OF COUNTY WEED COMMISSIONER, AND TO PROVIDE FOR HIS APPOINT-

MENT AND DUTIES. .

Be tt Enacted by the General Assembly of the State of Iowa:

That Section One (1) of said chapter be amended by adding
thereto the following:

Section l-a. The office of County Weed Commissioner is hereby
ereated. It shall be the duty of the County Board of Supervisors,
at a regular or special meeting of the Board, not later than the
first day of April in each year, to appoint a County Weed Com-
missioner whose term of office shall be from the first day of May
after his appointment to the first day of November following.

Section 1-b. The County Weed Commissioner shall devote his
entire time to the duties of his office, and shall receive as full com-
pensation for his services a salary not exceeding seventy-five dol-

51

802 WEED FLORA OF IOWA

lars ($75.00) per month and his actual and necessary traveling ex-
penses incurred while performing his official duties, payable in like
manner as the salaries of other county officers.

Section 1-c. The Board shall furnish such weed commissioner
an office at the county seat, and all stationery, blanks and supplies
necessary in the performance of his official duties.

That Section Two (2) of said chapter be amended by changing
the period at the end of said section to a comma, and adding im-
mediately thereafter the following:

And shoo-fly (Hibiscus Trionum), and wild carrot (Daucus
Carota).

That all of Section Three (3) of said chapter following the
words ‘‘in this act,’’ in the ninth line thereof, be stricken out and
the following enacted in lieu thereof:

Section 3-a. It shall be the duty of the County Weed Commis-
sioner during the first thirty (30) days of his term of office, to
post in public places in each township of the county, at least fifteen
(15) notices setting forth therein, in substance, the law of the
State of Iowa in reference to noxious weeds and the destruction
thereof; to inspect all lands, including highways and railway
rights-of-way within the county, for noxious weeds, as defined in
Section Two (2) hereof, and give to the owners or occupants of
said land, and to the officers responsible for the care of the high-
ways on which any such noxious weeds be found, information in
reference to the presence of such weeds and the manner of destruc-
tion thereof.

Section 3-b. If any occupant or owner of land, or any owner
or operator of a railway right-of-way, neglect or refuse to destroy
the noxious weeds upon his land or right-of-way or shall fail to
prevent the said noxious weeds from blooming or coming to ma-
turity, when such weeds are likely to be the means of infesting the
public highways, or the lands of adjoining owners, the County
Weed Commissioner shall cause such noxious weeds to be prevented
from maturing seed, or shall cause such noxious weeds to be per-
manently destroyed and the cost thereof, not exceeding (30) cents
per hour for each man so employed, shall be recovered from the
owner of the land, or owner or operator of such railway right-of-
way by a special tax certified to the county auditor by the County
Weed Commissioner to be paid by the owner or operator of the
land or railway right-of-way as the case might be, and collected
by the county treasurer the same as other taxes.

WEED AND SEED LAWS 803

- Section 3-c. If any township trustee or other officer, or officers,
responsible for the care of the public highways in each township
or county in this state, neglect or refuse to destroy any noxious
weeds upon such highway, or shall fail to prevent the said noxious
weeds from blooming or coming to maturity, when such weeds are
likely to be the means of infesting the land adjoining such high-
ways, the County Weed Commissioner shall forthwith give written
notice to such officer or officers, responsible for the care of such
highways, to destroy such noxious weeds, and if such officer or
officers Shall neglect for ten (10) days after such notice to destroy
such weeds, or to prevent the same from maturing seed, then such
officer, or officers, shall be subject to the penalty provided in Sec-
tion Hight (8) of this chapter.

Section 3-d. The County Weed Commissioner shall make a re-
port of the work of his term to the Board of Supervisors, not later
than the thirtieth (30th) day of October of the year for which he
was appointed, such report to contain a statement in detail on the
presence and location of Canada thistle, horse nettle and quack
grass, and the board shall forward a copy of such statement to the
Secretary of the lowa Department of Agriculture not later than
the first day of December following:

Section 3-e. It shall be the duty of the Secretary of the lowa
Department of Agriculture to furnish to the Board of Supervisors
of each county, the notices described in Section 3-a hereof, as well
as all necessary blanks for reports to be made to said department,
and to keep on file in his office all reports of such noxious weeds
furnished him by County Boards of Supervisors, and include in
his annual report a summary of the report furnished by such
boards.

This act being deemed of immediate importance shall take effect
and be in force from and after its publication in the Register and
Leader and the Des Moines Capital, newspapers published in Des
Moines, Iowa.

ILLINOIS.

In Illinois the criminal code statutes provide a penalty of not
less than $10.00 nor more than $100.00 for bringing Canada thistle
in packing material or in grain, grass or vegetable seed on any
land in this state; nor shall it be permitted to go to seed. The same
law also applies to railroads. This includes other noxious weeds
growing on the right-of-way of other land operated by railways,
but the fine is placed at not less than $50.00 nor more than $200.00.

804 WEED FLORA OF IOWA

An Illinois statute provides for the appointment of a commis-
sioner of Canada thistles by the board of town auditors in counties
under township organization and by the county commissioner in
counties not under township organization for each township or
election precinct and by the city council of any city or by the
president and trustees of any town or village as the case may be,
the former to hold his term of office for three years. Compensation
$2.00 per day. The commissioner shall diligently enquire concern-
ing the introduction and existence of Canada thistles in his town-
ship or precinct. He shall take care that they do not go to seed,
or otherwise spread. The commissioner shall advise with the owner
of the land concerning treatment. The limit of money to be ex-
pended by the commissioner shall not be more than $100 on any
one infested tract. The commissioner shall make out a written re-
port to the supervisor of the town or to the county commissioner.
The report shall be read publicly at the annual town meeting, as
to whether any thistles are growing; if growing, where; it shall
contain a statement as to the treatment of the infested tract and
shall make such other suggestions as may seem proper. He shall
forward a copy to the secretary of the state Board of Agriculture.

A land owner shall not deposit weeds or trash on the public
road. The same chapter provides that the commissioners of high-
ways in their respective towns shall enforce the law with reference
to cocklebur, Canada thistle and Russian thistle.

INDIANA.

The Indiana law makes it a misdemeanor for any person or
corporation, on property belonging to the person or corporation,
to allow Canada thistles to grow until they become the length of
6 inches from the surface of the ground to the tip of the stem.
The law makes it a misdemeanor for persons having charge of high-
ways to allow Canada thistle to grow to the length of 6 inches or
to mature. It makes it the duty of the road supervisor or of the
president of the board of trustees, to notify the occupant of the
land on which Canada thistle grows to cut said thistles below the
surface of the ground within 5 days of notice. Penalty is attached
for not complying with the notice. A penalty is also attached to
non-performance of the duties of the supervisor, township trustee
or mayor.

WEED AND SEED LAWS 805

KANSAS.

The state of Kansas has several statutes in regard to the destruc-
tion of weeds: one on Canada thistle and Russian thistle; another
on Johnson grass. Chapter 17: 923, of the revised statutes, re-
quires cities of the first class to enforce the cutting and destruc-
tion of weeds on vacant lots, pieces of land, streets and alleys.
A five days’ written notice shall be given; if not removed the city
may make a special assessment the same as for sidewalks. Chapter
16 gives cities of the first class the power to pass an ordinance on
the removal of rank grass and weeds. Chapter 41 makes it the
duty of the owner of real estate to cut the weeds along said real
estate before they go to seed. The Canada thistle and Russian
thistle laws make it the duty of every corporation, owner of land,
or the occupier of lands where these weeds occur to remove the
same at such times as the board and county commissioners may
direct. When not removed, notice shall be published in one or
more county papers not less than three weeks before the fixed time
of destruction. The highway overseer of every township or county
shall also cut or destroy all noxious weeds on the highway. The
Johnson grass statute makes it unlawful to introduce into or sell
or offer for sale within the state any seeds or roots of Johnson
grass. It is made the duty of the county commissioner of each
county within the state where Johnson grass occurs to prescribe
the jurisdiction of each road overseer; each township to be in-
eluded within the jurisdiction of some road-overseer. It is made
the duty of the road overseer to prevent its spreading and if he
receives written notice from any person in writing that the grass
is seeding he shall investigate; if found to be the case he shall
give 5 days’ time in which to destroy it, if not destroyed he shall
remove it and tax the costs against the land. If the owner of the
land fails to notify tenant, on execution of lease, the owner shall.
be responsible for any J SUDE ES: ‘‘Wull tassel,’’ as contained in
law, shall mean seed.

MINNESOTA.

In regard to the suppression of noxious weeds in Minnesota the
law is as follows: ‘‘Where the dean of the department of agri-
culture of the university of Minnesota deems it necessary for the
suppression of noxious weeds and for experimental purposes to
sow timothy, clover, red top or other seeds on burned-over state
lands, said department is hereby authorized to do so with seed
purchased under this act.’’

806 WEED FLORA OF IOWA

‘*Any county commissioner who knowingly allows or aids in
allowing to any such applicant under this act any timothy, clover,
red top or other seed, unless such applicant belongs to the class
referred to, who is destitute of needed seeds, shall be guilty of a
misdemeanor.’’

MISSOURI.

The revised statutes of Missouri make it the duty of the owner,
lessee or other occupant of lands and every railroad company or
corporation in the state to destroy Canada thistle and Scotch
thistle, prevent the formation of seed, and prevent said thistles
from spreading. A penalty of ten dollars is attached for every
offence. Notice shall be given to the agent, overseer or other
person having charge of the streets, roads or highways or places
where such thistles occur. Cases of violation may be brought be-
fore any justice of the peace of the county or city. Said fine when
recovered shall be paid into the county school fund. Where such
cutting is done on land by the overseer the cost is charged as a
tax against the property and collected as other taxes. The law
prohibits the throwing away of material with Canada thistle and
Scotch thistle seed and provides for the burning of straw or grass
packing containing thistle.

NEBRASKA.

In the state of Nebraska, there are two statutes concerning the
destruction of weeds, one pertaining to the destroying of weeds
in public roads, the main provisions in the law being as follows:
It is the duty of land owners in the state to mow or otherwise
destroy all weeds to the middle of all public roads running along
their lands, at least once each year, namely, between the fifteenth
day of July and the fifteenth of August. The overseer of roads
has authority to cut the weeds when complaint is made; expenses
connected therewith shall be sent to the county clerk who shall
make an assessment against the land. The usual penalty is also
provided.

In a second statute there is provision for the city of Omaha for
the destruction of weeds and worthless vegetation upon vacant
lots or land in the city of Omaha.

NORTH DAKOTA.

The state of North Dakota has a law which seeks to prevent the
spread of noxious weeds by threshing machines. This act provides
that any owner, or teamster employed in hauling grain, either

WEED AND SEED LAWS 807

threshed or unthreshed, shall upon completing any threshing en-
gagement and before leaving the premises on which said work was
done take all reasonable care to prevent the conveying and carry-
ing away and scattering of noxious weeds which may have ac-
cumulated in or on the machines. The law provides how this shall
‘be done by operating the machine and sweeping. A printed copy
of the law shall be kept posted on every machine operating in the
state. A fine, or imprisonment, or both, is provided for violation
of the law. J am told the law is not enforced.

OHIO.

The state of Ohio has several laws relative to the destruction of
weeds, briers and brush. With reference to the destruction of
these on toll, steam, and electric roads the law provides for the
destruction of brush, briers, burs, Russian, Canada, or common
thistle, wild lettuce, wild mustard, wild parsnip, ragweed, milk-
weed, ironweed, and all other noxious weeds growing within the
limits of any right of way whether in actual operation or not. If
said weeds are not destroyed between the first and twentieth of
June and between the first and twentieth of August and if neces-
sary between the first and twentieth of September of each year,
the trustees of the township through which such road passes shall
cause it to be done and shall have right of action against such
toll, steam, or electric road and one hundred per cent penalty;
costs of action to be recovered before any justice of the peace of
such county. The weed law as applied to the destruction of weeds
* on graveled or improved roads, turnpikes, county township roads,
streets, etc., is essentially the same, putting the enforcement in the
hands of pike superintendents and turnpike directors. The amount
of money which ean be collected is fixed at one dollar and a half
per day to destroy these weeds. A street commissioner shall be
paid for such services by the proper municipal authorities. The
land owner or tenant is allowed to cut the noxious weeds along
the highway abutting the property. The superintendent shall fix
a reasonable compensation for the work.

Another section provides that upon written information that
Canada thistle, Russian thistle, wild lettuce or wild mustard is
growing on land in a township and is about to spread or mature
seeds between the first day of June and the fifteenth day of Oc-
tober, the trustees of the township shall serve written notice upon
the owner, lessee, agent or tenant that such weeds occur and that

808 WEED FLORA OF IOWA

they must be destroyed within five days after the service of such
notice. These laws are not enforced in Ohio.

SOUTH DAKOTA.

The South Dakota law specifies that every person or corporation
shall destroy, on all land which he or it may occupy, all weeds of
the following kinds: Russian thistle, Canada thistle and cockle-
bur. The enforcement of the law is in the hands of the board of
supervisors. If the weeds are not destroyed a notice for three
weeks shall be published in the papers. After such notice the
weeds shall be destroyed. Owners must also destroy weeds on
highways abutting their property. These weed laws are not en-
forced.

WISCONSIN.

The state of Wisconsin has a law requiring that every person
or corporation shall destroy, on land which: he or it shall own,
occupy, or control, all weeds known as Canada thistle (Cirsium
arvense), ox-eye daisy (Chrysanthemum leucanthemum) snap
dragon (Linaria vulgaris), sow thistle (Sonchus arvensis), sour
dock and yellow dock (Rumex crispus), mustard (Brassica ar-
vensis), wild parsnip (Thaspiwm barbinode), burdock (Lappa
officinalis), Russian thistle (Salsola kali) and wild barley (Hor-
deum jubatum), at such times and in such manner as shall ef-
fectually prevent them from bearing seed. The above weeds shall
be destroyed to the middle of the highways by the commissioner of
noxious weeds. The corporation or party shall be given notice -
and if weeds are not removed within 6 days a $5.00 fine is im-
posed every day thereafter during which such neglect shall con-
tinue. The weeds shall be specified; also on what land they occur.
The commissioner or commissioners of weeds shall be appointed
by the chairman of each town board, the president of each village,
or the mayor of each city. The commissioner of weeds shall hold
the office for one year. He shall give notice if the weeds are not
removed. Then the commissioner shall remove the same. The
city of Milwaukee is exempt from these provisions.

SEED LEGISLATION.

Numerous states of the Union and various European countries
as well as Canada and other British countries have legislated on
the subject of seeds and seed adulteration. Two classes of laws
are in vogue in the United States. One requires a guaranty of

WEED AND SEED LAWS 809

the seed sold and may be called the Maine idea. The other gives
standards of purity and vitality and is the Iowa idea. This law
has been passed in many states, among them, Wisconsin, Wash-
ington and Wyoming. The Jowa law is as follows:

Section 1. Every lot in bulk, bag, pail, parcel or package of
concentrated commercial feeding stuffs as defined in section three
(3) of this act; and every parcel, package or lot of agricultural
seeds as defined in section nine (9) of this act, and containing one
pound or more, offered or exposed for sale in the state of Iowa,
for use within this state, shall have affixed thereto, in a conspicuous
place on the outside thereof, distinctly printed in the English
language, in legible type not smaller than eight point heavy
gothic caps, or plainly written, a statement certifying:

In the case of agricultural seeds: .

First. The name of the seed.

Second. Full name and address of the seedsman, importer,
dealer or agent.

Third. A statement of the purity of the seed contained, specify-
ing the kind and percentage of the impurities as defined in sec-
tions eleven (11) and twelve (12) hereof, provided that said seeds
are below the standards fixed in this act.

Fourth. Locality where said seed was grown, when known.

Section 6. The state food and dairy commissioner shall cause
to be made analyses of all agricultural seeds sold or offered for
sale in this state. Said state food and dairy commissioner is here-
by authorized, in person or by deputy, to take for analysis a sam-
ple from any lot or package of agricultural seeds not exceeding
four ounces in weight; but said sample shall be drawn or taken in
the presence of the party or parties in interest, or their repre-
sentative, and shall be taken from a parcel, lot or number of par-
cels which shall not be less than five per cent of the whole lot in-
spected and shall be thoroughly mixed and divided into two sam-
ples and placed in glass or metal vessels carefully sealed and a
label placed on each, stating the name or brand of the agricultural
seeds or material sampled, the name of the party from whose
stock the sample is drawn, and the date and place of taking such
sample, and said label shall be signed by the state food and dairy
commissioner, or his authorized agent; or said sample may be
taken in the presence of two disinterested witnesses; one of said
duplicate samples shall be left on the premises of the party whose
stock was sampled and the other retained by the state food and

810 WEED FLORA OF IOWA

dairy commissioner, for analysis and comparison with the certified
statements required by sections one (1) and four (4) of this act.
The result of the analysis of the sample, together with additional
information shall be published from time to time in bulletins issued
by the state food and dairy commissioner upon approval of the
executive council.

Section 7. Any person purchasing any agricultural seeds in
this state for his own use, may submit fair samples of said seeds
to the state food and dairy commissioner, who, upon receipt of an
analysis fee of fifty cents (50c) for each sample of agricultural
seeds shall cause an analysis of the same to be made.

- Section 8. No person shall sell in ground form, wheat or rye
screenings containing cockle or other poisonous or deleterious sub-
stances.

Section 9. The term, agricultural seeds, as used in this act,
shall include the seeds of the red clover, white clover, alsike clo-
ver, alfalfa, Kentucky blue grass, timothy, brome grass, orchard
grass, red top, meadow fescue, oat grass, rye grass and other
erasses and forage plants, flax, rape and other cereals.

Section 10. No person shall sell, offer, or expose for sale, or
distribution in this state, for the purpose of seeding, any of the
agricultural seeds as defined in section nine (9) of this act, unless
the said seeds are free from the seeds of the following weeds:
Wild mustard, or charlock (Brassica sinapistrum), quack grass
(Agropyron repens), Canada thistle (Cmcus arvensis), wild oats
(Avena fatua), clover and alfalfa dodder (Cuscuta epithymum),
field dodder (Cuscuta arvensis), and corn cockle (Lychnis githago).

Section 11. The seeds of the following weeds shall be consid-
ered as impurities in the agricultural seeds as defined in section
nine (9) of this act, sold, offered, or exposed for sale, within the
state for the purpose of seeding: White cockle (Lychnis vesper-
tina), night-flowering ecatchfly (Silene noctcflora), curled dock
(Rumex crispus), smooth dock (Rumeax altissimus), sheep sorrel
(Rumer acetosella), yellow trefoil (Medicago lupulina), burr clover

(Medicago denticulata), sweet clover (Melilotus alba and officinalis) ,
black mustard (Brassica wigra), plantain, buckhorn (Plantago
lanceolata), bracted plantain (Plantago aristata), bindweed (Con-
volvulus sepium), smooth crab grass (Panicum glabrum), common
chickweed (Stellaria media). When such impurities or any of
them are present in quantity exceeding a total of two per cent of
the weight of said agricultural seeds, the approximate percentage of

WEED AND SEED LAWS 811

each shall be plainly indicated in statement specified in section
one ‘1) of this act.

Section 12. Sand, dirt, chaff and foreign substances and seeds
other than those specified in sections thirteen (13) and fourteen
(14), or broken seed and seed not capable of germinating, shall be
considered impurities when present in agricultural seeds sold, of-
fered, or exposed for sale, in this state, for the purpose of seeding,
and when such impurities, or any of them, are present in quantity
exceeding the standards of purity and viability authorized in sec-
tion sixteen (16) of this act, the name and approximate percentage
of each shall be plainly indicated in the statement specified in
section one (1) of this act.

Section 13. For the purposes of this act, seeds shall be deemed
to be mixed or adulterated :

First. When orchard grass (Dactylis glomerata) seed contains
10 per cent or more by weight of meadow fescue (Festuca elatior
pratensis) seed, or Italian rye grass (Loliwm italicum) seed, or
English rye grass (Lolium perenne) seed.

Second. When blue grass or Kentucky blue grass (Poa pra-
tensis) seed contains 5 per cent or more by weight of Canadian
blue grass (Poa compressa) seed, red top chaff, red top (Agrostis
alba) seed, or any other seed or foreign substance.

Third. When red clover (Trifolium pratense), mammoth red
clover (Trifolium pratense var.), or alfalfa (Medicago sativa),
contains 5 per cent or more by weight of yellow trefoil (Medicago
lupulina), or sweet clover (Melilotus alba and M. officinalis) seed
or bur clover (Medicago denticulata) seed.

Fourth. When rape (Brassica rapa) contains 5 per cent or
more of common mustard (Brassica sinapistrum) or black ee
(B. mgra). 3

Section 14. For the purposes of this act, seed shall be deemed”
to be misbranded:

First. When meadow fescue (Festuca elatior pratensis), Eng-
lish rye grass (Lolium perenne) or Italian rye grass (Loluum
italicum) is labeled or sold under name of orchard grass (Dactylis.
glomerata) seed.

Second. When Canadian blue grass (Poa compressa) seed, red
top (Agrostis alba) seed, or any other seed not blue grasy seed, is
sold under the name of Kentucky blue grass or blue grass (Poa
pratensis) seed. |

Third. When yellow trefoil (Medicago lupulina), bur clover
(Medicago denticulata) or sweet clover (Melilotus alba) is sold

812 WEED FLORA OF IOWA

under the name of clover, June clover, red clover, (Trifolium
pratense), mammoth red clover, medium red clover, small red
clover, sapling clover, peavine clover (7. pratense var.). or alfalfa
(Medicago sativa) seed.

Section 15. The provisions concerning agricultural seeds con-
tained in this act shall not apply to:

First. Any person or persons growing or selling seeds for food
purposes only, or having such seeds in possession for sale for such
purposes.

Second. Any person or persons growing or selling seeds direct

to merchants to be cleaned or graded before being offered for sale
for the purpose of seeding. This shall not, however, exempt the
seller from the restrictions of section ten (10) of this act.

Third. Seed that is held in storage for the purpose of being re-
cleaned, and which has not been offered, exposed or held in pos-
session of or for sale for the purpose of seeding.

Fourth. Seed marked ‘‘not absolutely clean,’’ and held or sold
for export outside the state only.

Fifth. The sale of seed that is grown, sold and delivered by
any farmer on his own premises for seeding by the purchaser him-
self, unless the purchaser of said seeds obtains from the seller at
the time of the sale thereof a certificate that the said seed is sup-
plied to the purchaser subject to the provisions of this act.

Sixth. Mixtures of seeds for lawn or pasture purposes. This
shall not, however, exempt the seller of such mixtures of seeds
from the restrictions of sections ten (10) and eleven (11) of this
act.

Section 16. The following standards of purity (meaning free-
dom from weed seeds or other seeds) and viability are hereby
fixed :

STANDARD OF PURITY AND VIABILITY OF AGRICULTURAL SEEDS.

Name of Seed Per cent of ae

purity eermureple
Alfalfa (Medicago sativa) ...............+0.. 96 80
SHENG Ch alte Ree: Gites 3.0 5,06 Ot ae 8 Sos 98 90
Blue grass, Canadian (Poa compressa)...... 90 45
Blue grass, Kentucky (Poa pratensis)........ 80 45
Brome, awnless (Bromus inermis).......... 90 75
Clover, alsike (Trifolium hybridum)........ 90 75
Buck wheats cccceer een eek Petrone ress «ieee ceva 96 90
Clover, crimson (Trifolium incarnatum)..... 98 85

Clover, red (Trifolium pratense)............ «92 80

WEED AND SEED LAWS 813

STANDARD OF PURITY AND VIABILITY OF AGRICULTURAL
SEEDS—ContTINUED.

Per cent of
Name of Seed Her cee of | ee
Clover, white (Trifolium repens) .......... 90 15
Corn, field® (Zea MAYS). 226s. ccc cece ee sss eee 99 94
COTM IS WCE oor cele tebe eiiettis a cic ae icleve se este ise 99 75
Fescue, meadow (Festuca pratensis)........ 95 85
Flax (Linum usitatissimum) .....--.++-.00- 96 89
Millet, common (NSetaria italica)............ 90 85
Millet, hog (Panicum miliaceum)........... 90 85
Millet, pearl (Pennisetum typhoideum)...... | 99 65
ORS (AWE STUIMG)) saab doooo bobo UObbOGbb ES 98 90
Oat grass, tall (Arrhenatherum avenaceum) . 72 70
Orchard grass (Dactylis glomerata)......... 70 70
IRB. (URFUSRICT THO) cosoaponeoccuec oH odo 99 90
Red top (Agrostis alba) ...........ceeeeees 90 70
le (SGGHIG GEE) Woseaegocuoaudesoeouens 98 90
Rye grass, perennial (Lolium perenne)...... 96 90
Rye grass, Italian (Lolium italicum)........ 95 80
Sorghum (Andropogon sorghum) ........... 96 80
Som=lntion, ioe iWwoylcleir SoogegocaeuooDmoeeooU Or 90 60
Timothy (Phlewm pratense) ....... feta absialee 96 85,
Waheat, 1 CLR UGUCTEIM eriars oleic esos arse ie = o.6j\e sie) Shere lees 98 90

Section 17. It is hereby made the duty of the state food and
dairy commissioner to enforce the provisions of this act. The in-
spectors, assistants and chemists appointed by the state food and
dairy commissioner shall perform the same duties and have the
same authority under this act as are prescribed by chapter one
hundred and sixty-six (166), laws of the thirty-first general as-
sembly, and the said state food and dairy commissioner may ap-
point, with the approval of the executive council, such analysts and
chemists as may be necessary to carry out the provisions of this
act.

Section 18. Whoever sells, offers or exposes for sale any of the
seeds specified in sectiony thirteen (13) and fourteen (14) of this
act which are mixed, adulterated or misbranded, or any agricul-
tural seeds which do not comply with sections ten (10), eleven (11)
and twelve (12) of this act, or who shall counterfeit or use a
counterfeit of any of the tags prescribed by this act; or who shall
prevent or attempt to prevent any inspector in the discharge of
his duty from collecting samples or who shall violate any of the
provisions of this act shall be guilty of a misdemeanor, and upon
conviction, shall be fined not more than one hundred dollars ($100)
and costs of prosecution; provided, that no one shall be convicted

814 WEED FLORA OF IOWA

for violation of the provisions of section ten (10) of this act if
he is able to show that the weed seeds named in section ten (10)
are present in quantities not more than one in ten thousand, and
that due diligence has been used to find and remove said seeds.

Section 19. There is hereby appropriated, for the purpose of
enforcing the provisions of this act, a sum not exceeding three
thousand dollars ($3,000) annually. Such expense shall be paid
by warrant of the state auditor upon bills filed by the state food
and dairy commissioner with the executive council and approved
by them. All fees collected under the provisions of this act shall
be paid into the state treasury.

The Michigan law permits the sale of cereal grasses, clover, and
forage plants containing two per cent of quack grass, charlock,
black mustard, Canada thistles, chicory, toad flax, buckhorn,
Rugel’s plantain, night-flowering catchfly, and pennycress. The
adulteration shall not be more than five per cent of any other
distinguishable seed, sand, crushed rock or any other materials to
be found mixed with agricultural seed. When found to be wilfully
adulterated or not as clean as it is commercially practicable to
make it, the results should be published in a bulletin together with
names of the persons selling the same.

The Canadian act requires that no person shall sell or offer for
sale, seed, cereals, grasses, clovers or forage plants unless they
are free from any seeds of wild mustard, hare’s-ear mustard, bull
mustard, field pennycress, wild oats, bindweed, perennial sow
thistle, ragweed, greater ragweed, purple cockle, cow cockle, orange
hawkweed, and ergot. This law has done much to stimulate the
sale of good seed.

The enforcement of the Wisconsin law is placed in the hands of
the Agricultural Experiment Station.

The Maine law requiring a guaranty of seed sold in that state
is working out well and has greatly improved the quality of seed
sold in that state.

The North Dakota law has the following forbidden weed seeds:
couch or quack grass, Canada thistle, sow thistle, and dodder.
Also the sale of agricultural or garden seeds containing more than
a reasonable trace of the seeds of greater ragweed, cornflower,
marsh elder, Russian pigweed, dandelion, chicory, Russian thistle,
plantain, buck plantain, bracted plantain, white cockle, cow cockle,
curled dock, sorrel, sheep-sorrel, purslane, bindweed, wild buck-
wheat, wild onion, wild oats, pigeon grass, holy grass, chess, mus-

WEED AND SEED LAWS 815

tard, tumbling mustard, hare’s-ear mustard, pennycress, pepper-
grass, shepherd’s purse, false-flax, bird’s-foot, trefoil, yellow. tre-
foil, bur clover, sweet clover, ergot, or of the seeds of any other
noxious weed is unlawful. The inspection of the law is in the
hands of the botanists of the North Dakota Agricultural College.
The law has greatly improved the quality of seeds sold in that
state. The forbidden list of weed seeds is large and probably
difficult to enforce.

The only way to enforce any seed law is to have fields in which
commercial seed is grown inspected’ by some competent botanist.
The seed should not be sold unless the weed seeds can be removed.

CHAPTER XIII.

HISTORY AND BIBLIOGRAPHY

L. H. PAMMEL HARR ETT . KELLOGG
and

CHARLOTTE M. KING

CHAPTER XIII.

HISTORY AND BIBLIOGRAPHY.

Perhaps the best known of the modern German treatises on the
subject of weeds is that of Thaer of the University of Giessen on
the Agricultural Weeds, in which some 27 species are described
with colored figures, methods of extermination being given. Many
of the weeds here described, as the sheep sorrel, corn cockle,
Canada thistle, quack grass, and horse-tail, are common to North
America. This work passed through several editions; the first ap-
pearing in 1881 and the last in 1905.

L. Danger in 1887 published a treatise of 166 pages on the sub-
ject of Weed and Plant Parasites. This work discussed the more
important weeds of Germany, frequently giving methods of ex-
termination, and numerous notes on the origin of weeds, including —
also, under the head of Geographical Botany, a list of weeds found
in different soils. The following soils are characterized: (1) Gra-
velly soils containing 80 per cent of gravel; under this head he
names such weeds as the horse weed (Hrigeron canadensis) and
spurge (Huphorbia peplus). On the whole, however, the list is a
short one. (2) Sandy soils, in which there is 80 per cent of sand
of smaller diameter than in gravel soils. The weeds found here
are awned brome grass (Bromus tectorwm), sheep sorrel (Rkumex
acetosella), common evening primrose ( Oenothera biennis), corn
cockle (Agrostemma githago), horse weed (Hrigeron canadensis),
and spurge (Euphorbia cyparissias). (3) Loamy soils with some
sand, lacking lime. Some of the weeds found here are sow thistle
(Sonchus arvensis), Canada thistle (Cursiwm arvense), shepherd’s
purse (Capsella bursa-pastoris), dandelion, (Taraxacum officinale) ,
wild carrot (Daucus carota) and chess (Bromus secalinus). (4)
Clay soils. This class contains only one of our common weeds,
namely horse-tail (Hquisetum arvense). (5) Marl soils, contain-
ing from 5 to 50 per cent of carbonate of lime. The only weed
given in this list that we have in Iowa is prickly lettuce (Lactuca
scariola). (6) Limy soils, containing more than 50 per cent of
calcium carbonate, are represented by some Cruciferae, and
Leguminosae. (7) Humus soils, the organic matter consisting of

§20 WEED FLORA OF IOWA

about 50 per cent of humus; the humus mentioned must be in the
nature of peat, as the list of plants mentioned all belong to the
peat flora. (8) Alkali soils. The plants mentioned here: are
hardly characteristic in this state, only a few of the species being
reported in old lake beds in northern Iowa. Some of the weeds
mentioned by him are Triglochin maritima and Juncus balticus.
This author also gives more or less extended accounts of the
methods of extermination of these weeds in Germany.

Sorauer and Frank discuss the weeds of Germany. Stebler and
Schroeter discuss, in an extended way, in a work appearing in
1891, the weeds of Switzerland, giving many colored illustrations
and good descriptions. Numerous other papers also have ap-
peared in German technical agricultural journals and in the
transactions of societies.

William Darlington of West-Chester, Pennsylvania, was a
pioneer along the line of writing a special treatise on the subject
of weeds; for in 1847 he wrote a work on agricultural botany, an
enumeration and description of ‘‘useful plants and weeds, which
merit the notice or require the attention of American agricul-
turalists.’? He says in the preface:

The study of Botany, in its widest sense—comprising, as it does,
the entire vegetable creation,—will ever have its select votaries in
those who can appreciate its manifold charms, and find their re-
ward in the pleasures incident to the pursuit; but when regarded
in a more limited and practical point of view, it may fairly chal-
lenge the attention even of the most inveterate Utilitarians.......
In my humble opinion, no education can be deemed sufficient
without some acquaintance with the rudiments, or first principles,
of Botanical Science—some rational knowledge of the vast and
multiform creation around us, known as the Vegetable Kingdom.
As eae If our American youths who are being educated with a
view to Agricultural pursuits, were thoroughly instructed in the
admirable Textbook, above referred to, (Botanical Textbook by
Prof. A. Gray),—and were then required to make themselves
botanically acquainted with that portion of the vegetable king-
dom which annually demands their attention, on the farm,—the
Profession would speedily assume a new and engaging aspect.
The labors of the field would be blended with the contemplation of
facts and phenomena of the deepest interest to inquiring minds,—
and Agriculture—instead of being shunned, as an irksome drudg-
ery—would be justly esteemed as one of the noblest employments
of a free and intellectual people.

In the revised second edition a weed is defined as follows:
In popular language, any homely plant which is not noticeable
for the beauty of its flowers, not entitled to respect by a reputa-

HISTORY AND BIBLIOGRAPHY 821

tion for medicinal or other useful qualities, is designated by the
epithet weed. In an agricultural sense, the term is used with a
more restricted meaning, and is applied to those intrusive and un-
welcome individuals that will persist in growing where they are
not wanted,—in short, the best definition that has yet been given
of a weed is the old one, ‘‘a plant out of place.’’ Most of the
weeds troublesome in our agriculture are immigrants, either from
the Old World, or from the warmer portions of this continent.
The number of plants indigenous to our country, that are entitled
to rank as pernicious weeds, is comparatively small. As the
aborigines disappear with the advance of the whites, so do the
native plants generally yield their possession as cultivation ex-
tends, and the majority of the plants to be met with along the
lanes and streets of villages, and upon farms, are naturalized
strangers, who appear to be quite at home, and are with difficulty
to be persuaded or driven away.

Weeds are introduced upon a farm in a variety of ways. Many
have their seeds sown with those of the crops; this is particularly
the case where the seeds of the weeds and of the grain are so
nearly alike in size that their separation is difficult. Proper care
in procuring and preserving clean seed will often save much
future trouble and vexation. The observing farmer will notice
the means which nature has provided for the scattering of seeds,
and he will find that the most pernicious weeds seem to have been
especially furnished with contrivances to facilitate their dispersion.
The Clot-bur, Beggar’s Lice, and others, have barbs or hooks by
which they adhere to clothing and the coats of animals, and are
widely distributed by this agency. All of the thistles, and many
others of the same family, have a tuft of fine silky hair attached
to the seed, or more properly fruit, by which they are buoyed upon
the air, and wafted from place to place. So numerous are the
ways by which seeds are dispersed, that, however careful a farmer
may be upon his own premises, a slovenly and neglectful neighbor
may cause him infinite annoyance by furnishing his lands with
an abundant supply. In some European countries a farmer may
sue his neighbor for neglecting to destroy the weeds upon his
lands, or may employ people to do it at the delinquent’s expense.

The vitality of seeds, particularly if buried in the earth below
the reach of the influences which cause germination, in some cases,
endures through many years; hence, an old field, after deep plow-
ing, has often a fine crop of weeds from the seeds thus brought
to the surface. Weeds that have been cut or pulled after they
have flowered, should not be thrown into the barnyard or hog-
stye, unless the farmer wishes to have the work to do over again
with their progeny, as the seeds will be thoroughly distributed in
the manuring of the land. In England they dry the pernicious
weeds and burn them, not only destroying root and branch, but
seed also.

822 WEED FLORA OF IOWA

He introduces the subject by giving an account of the structure
of plants. Throughout this admirable treatise, under the head of
observations, Dr. Darlington gives an account of the troublesome
weeds. The book describes such weeds as Indian mallow, bladder
ketmia, common mallow, quack grass, horse nettle, boot jack,
cocklebur, ragweed, dead nettle, smartweeds and European morn-
ing-glory. Strangely enough, however, the common morning-
glory is not mentioned, nor is the field dodder or the clover dodder.
This work passed through another edition revised by Dr. George
Thurber, a botanist of some note who was editor for a time of the
American Agriculturist and died in 1863. The second edition
of the book, under the title of American Weeds and Useful Plants,
appeared in 1859. This work filled a splendid place in American
agricultural literature and did much to stimulate a study of the
weeds which are injurious to agriculture.

Mr. Thomas Shaw in 1893 published a small book in which he
discussed the prevalence of weeds, the evils which arise from the
presence of weeds, the possibility of destroying weeds, the agencies
concerned in the distribution and propagation of noxious weeds,
methods and principles generally applicable in the destruction of
weeds and finally specific modes of eradicating certain trouble-
some weeds, which should generally be adopted to keep a field free
from weeds. He makes many excellent suggestions, among which
are the following:

(1) The persistent and careful study of the habits of growth
of all the various sorts of weeds with which one’s farm is infested,
so as to be able to deal with them in the most rational way possible.

(2) The modification (when necessary) of the scheme of rota-
tion that has been adopted, so that such crops as allow the seeds
of the weeds which infest them to ripen, may for a time, be omitted
from the rotation.

(3) When certain methods of eradication have been fixed upon,
the careful and wise adaptation of these methods to such condi-
tions of soil and climate as are found in the locality concerned.

(4) The exercise of due care when seeds are purchased, to see
that they are perfectly pure, that is, perfectly free from the seeds
of weeds; and also the exercise of due care with respect to such
seeds as are grown at home to see that they, too, are perfectly free
from weed seeds.

(oi) anne \((G)) Gave

(7) The growing of hoed crops upon the farm infested, to the

largest extent that is practicable.

HISTORY AND BIBLIOGRAPHY 823

(8) The growing of clover and lucerne, so far as this can be
done with profit.

(9) The growing of soiling crops, to the extent that may be
found practicable, both because of the fact that they can be cut
almost at any time that is desirable, and also because of their
‘“smothering’’ properties.

(10) The utilizing of sheep for the destruction of weeds in
pastures.

(11) The growing, as far as possible, at home, of the food re-
quired by the live stock of the farm, instead of purchasing it else-
where.

(12) The keeping of the land of the farm constantly at work,
so far as this possibly can be effected.

(13) The stimulation of the soil to a constantly vigorous .
production by means of thorough working and a large use of
manure. — ;

(14) The practice of autumn cultivation to the largest extent
that is possible.

(15) The exercise of the utmost possible precaution that no
weed seeds ripen upon the farm, if by any means whatever their
ripening can be prevented.

(16) The giving of due heed to all the agencies by which weeds
are distributed and propagated, so as always to be able to counter-
act or defeat those agencies.

(17) When once the work of eradication has been undertaken,
the making of it as thorough as possible, and the accomplishment
of it in the shortest possible time.

(18) When once a state of cleanliness has been secured, the
maintenance of it thereafter as perfectly as possible under all
circumstances.

In 1911 Orange Judd & Co. published a book on Weeds of the
Farm and Garden, which was written by L. H. Pammel. This
book contains, in addition to a number of half tone plates, figures
of a great many weeds of North America, discusses their geographi-
eal distribution and the best methods of extermination, and the
most important noxious weeds with their distribution. The table
of contents of the book is as follows:

1. Weeds. Injury to Crops and Nature of. 2. Kinds of Weeds
as to Duration. 3. Dispersal of Weed Seeds. 4. The Farmer’s
Interest in Good Seed, and How to Test Seed. 5. Weed Impurities
in Agricultural Seeds. 6. Some Weed Laws and Seed-Control

824 WEED FLORA OF IOWA

Laws. 7. Weeds of Special Crops. 8. Poisonous Weeds. 9. Table
of Noxious Weeds. 10. Migration of Weeds. 11. Extermination
of Weeds. 12. Treatment for Special Weeds. 13. Morphology of
Weeds. 14. Descriptions of Some Common Weeds. 15. Partial
Bibliography, Consisting of Easily Accessible References, Ar-
ranged by Harriette S. Kellogg. This lists the important papers
on the subject.

A little treatise, ‘‘A Talk on Weeds,’’ an address given before
the County Road School, Clinton County, 1910, gives an account
of a few of the important weeds and notes for the teacher. A
somewhat similar paper especially adapted for schools was pub-
lished by Miss Caroline Forgrave of Dallas county. This little
paper gives suggestions of what school children may do to study
weeds. Both of these were written by Mr. Pammel.

Bulletin 70 of the Iowa Agricultural Experiment Station, by
the same writer, discusses a few of the more important lowa weeds |
with an account of the dissemination of seeds and the pollination of
a few plants; subsequently Mr. Pammel and Miss King published
an extensive bulletin on the treatment of weeds, especially with
iron sulphate.

Prof. H. L. Bolley also published an extensive treatise on ‘‘ Weeds
of North Dakota,’’ particularly with reference to the treatment
with iron sulphate.

Attention may also be called to a little semi-occasional publica-
tion by the American Steel and Wire Company on ‘‘ Weeds,”’ par-
ticularly on treatment with iron sulphate. This little journal is
well illustrated. Many of the nature study works like those of
Hodge, Stevens, Birkett and Hall, Goff and Mayne, such as
‘“Weeds,’’ ‘‘Farm Friends and Farm Foes,’’ as well as the Agri-
cultural botany of John Percival, give short accounts of weeds.

W.S. Blatchley, in the ‘‘Indiana Weed Book,’’ 1912, describes
one hundred and fifty common weedy plants; including an account
of their nature and habits, as well as suggestions for eradication.
Of the weeds considered, it is interesting to note that seventy-
seven are natives of Indiana, while seventy-three are introduced
species. .

Of the more important treatises on weeds the recent bulletin by
J. W. Beal, who was formerly botanist of the Michigan Agricul-
tural College should be mentioned. This book of 167 pages de-
seribes and figures the important weeds of Michigan. This is a
most helpful treatise, and with the excellent figures one will be

HISTORY AND BIBLIOGRAPHY 825

able to recognize any of the common weeds of that state. Another
special bulletin is the Ohio weed manual by Prof. Selby. This
excellent manual describes and gives the distribution of Ohio
weeds as well as hints on extermination of the common weeds of
that state. The discussions on weeds by Crozier, Dewey and other
botanists of the United States Department of Agriculture, are
most helpful as regards the more common weeds of eastern North
America.

The most recent extensive account of weeds in Canada is a
book by Clark and Fletcher. This work describes many families
of weeds, one or more species of each genus being illustrated with
colored figures. In addition many weed seeds are described. Some
of the headings are as follows: Losses Due to Weeds, How Weeds
Spread, Weed Seeds in the Soil, Commercial Seeds and Feeding
Stuffs. This book will enable one to recognize the more or less
common weeds found in Canada. It has passed through two edi-
tions, the first having been published in 1906 and the second in
1909. .

The most recent English publication is a book by H. C. Long
and John Percival, ‘‘Common Weeds of the Farm and Garden.”’
This book of 451 pages contains many half tone illustrations and
figures of weeds that are common to the British Isles, treated under
the following heads: Weeds of Rivers and Ditches also Drives,
Worst Weeds, Weeds and the Improvement of Grass Land, Weeds
of the Arable Land, What Weeds Are and How They Affect our
Crops and Stock, Parasite Plants and Poisonous Plants, Principles
of Seed Testing, besides a Bibliography of 5 pages referring to
the more important papers published in Europe, England and
Canada. In addition to this English publication there have been
published by M. G. Smith ‘‘One Hundred Yorkshire Weeds,’’ and
‘**A Contribution to our Knowledge of the Influence of Manures on
the Botanical Composition of the Herbage of Permanent Grass-
Land.’’

Many weeds have received special attention in the United
States. Of these, perhaps the Russian thistle, some 20 years ago,
received more attention for a few years than any other weed. The
earliest account of this weed was made by J. N. Rose in 1891, fol-
lowed by a more extensive bulletin on the same weed by Dewey in
1893, and another paper by the same author in 1894. Papers were
also published by Bessey of Nebraska, Goff of Wisconsin, Pammel
and Wilson of Iowa, Hays of Minnesota, Bolley of North Dakota,

826 WEED FLORA OF IOWA

Williams of South Dakota, Clinton of Illinois, Selby of Ohio, and
Wooten of New Mexico; in addition press notices on the subject
were published in agricultural journals during the years 1891-
1895. Since then there have been comparatively few accounts, ex-
cepting a few notes in 1911 and 1912 in the agricultural journals.
The chemistry of the weed has also been discussed by G. E. Patrick
of Iowa and by the Colorado Experiment Station. This weed was
considered so important that a number of northern states passed
laws looking for its extermination. A bill was introduced into
Congress by Senator Hansbrough in which congressional aid was
asked to exterminate it.

The Canada thistle has been discussed by numerous writers both
in Europe and in the United States. The spread of this weed is
considered in another connection. We find, however, that mention
of this weed is made by Linnaeus in his Flora Lapponica, by
Ratzeburg in 1859, and by Darlington in 1853. More recently the
weed has received attention from such botanists as H. L. Bolley of
North Dakota, T. J. Burrill of Illinois, E. S. Goff of Wisconsin,
Fletcher and Clark of Canada, L. F. Henderson of Idaho, L. H.
Dewey of Washington, D. C., Prof. Howitt of Canada, and L. H.
Pammel. There have been many press notices in the agricultural
papers, particularly in the northern Mississippi Valley. Attention
may be called to those in Wallace’s Farmer, Iowa Homestead,
Breeders’ Gazette, Farmers’ Review, Prairie Farmer and Success-
ful Farming.

Another weed that attracted much attention a few years ago
was squirrel-tail grass or wild barley. This was discussed by C. S.
Crandall of Colorado, Hillman of Nevada, Nelson of Wyoming,
Wooten of New Mexico and Pammel of Iowa.

Prickly lettuce has been discussed by Arthur of Indiana, Weed
of Ohio, Dewey of Washington, D. C., Morrow of Illinois, Pammel
of lowa, and Fernald of Massachusetts.

Buffalo bur has been discussed by Henry of Wisconsin, Halsted
and Pammel of Iowa, Clinton of Illinois, Harvey of Maine, and in
numerous press notices in the agricultural journals.

Mustards of various kinds have been discussed by Dewey of
Washington, D. C., Clark and Fletcher of Canada, Hitchcock of
Kansas, Howitt of Canada and Pammel of Iowa.

The perennial sow thistle has been discussed by the agricultural
press of Canada and in special treatises by Howitt and Fletcher

HISTORY AND BIBLIOGRAPHY 827

and Clark of the Dominion of Canada and in numerous notices in
the agricultural press of the northern United States.

Broom rape has been discussed by Garman of Kentucky and by
the United States Department of Agriculture.

Much has been published on the subject of weed seeds. The
more important contributions are the following :*

European work.—The importance of this work has long been
recognized in Hurope. The pioneer work in this line was carried
on first in Germany, a station for testing commercial seeds having
been organized in 1867 in connection with an academy located in
Tharandt. Dr. Nobbe was its first director. Early in his work >
he saw the importance of making careful examination for the im-
purities of various grass and clover seeds. In 1876 appeared his
classical book, Handbuch der Samenkunde. In addition to this
work he was the author of many other important papers on via-
bility of seeds and other physiological seed problems.

Among other important contributions along this line, we may
mention the papers and work of Kraft, Luhn, and Harz. The work
of Harz summarizes not only the facts pertaining to the anatomy
of seeds but also to many other important topics; the literature
bearing on the subject of seeds is also given.

The work of Burchard on the adulteration of seed with special
reference to their origin is particularly noteworthy. In his book
he has published statistical records showing the origin of clover
seed and the weed seeds found in the same from Middle Europe,
Eastern Europe, Southern Europe and North and South America.
He sometimes missed the important weed species that are found
in our American clover seed, but on the whole it is true that the
character of the weed seeds found in our clover and other seeds
will enable one to tell where they were grown.

Burchard, in his account published in a contribution from the
Seed Control Station of Hamburg, states that a large number of

seeds investigated by him had impurities. Of two hundred and
— eighty seeds tested, one hundred and sixty-seven belonged to the
pulse family, seventy-nine to the grass family, twenty-three to
forest seeds, and eleven were miscellaneous. He found the mini-
mum purity of the clover seed was 54.2 per cent. The highest
percentage of purity was found in timothy, 99.42. The lowest
germinative energy was found in fescue grass, 0.17 per cent, and

*The more important references here given upon the history of seed investi-
gation are taken from bulletins 88, 99 and 105, issued by the Iowa State Agri-
cultural Experiment Station, which are more completely listed in the bibliography.

828 WEED FLORA OF IOWA

the highest in clover, 97.25 per cent. Of the sixty samples of red
clover examined for dodder, twenty-eight were free. The most
common species was clover dodder, although others were also found.
One lot of alfalfa from South America contained the Chilian
dodder. In this investigation as in others, he emphasizes the im-
portance of determining the kinds of weeds found in the seed,
thus: In Australian orchard grass the hairy brome grass was
common, and in North American seed, orchard grass, timothy, blue
grass and tickle grass.

The work of Settegast treats extensively the subject of agricul-
tural seeds and seed testing, especially with reference to vitality
and seed production.

Vandevelde’s work treats of the morphology and physiology of
germination and includes a splendid bibliography.

Attention should be called to the excellent contributions of
Wollny whose reports of his splendid work on seeds and the care
of agricultural crops often give considerable detail on the ger-
mination and viability of various agricultural seeds.

Kienitz gives a detailed account of the methods to be followed
in the study of germination of seeds.

Fruwirth carried out a study on the color and speeie gravity
of clover seeds. He found that the dark violet seeds were heavier
than the light colored ones of the same head, and perhaps had
greater germinative energy.

Samek carried on an experiment, testing seeds for a period of
eleven years, showing the results of germination after the first and
eleventh years.

Hiltner in a somewhat recent paper discusses the limitations of
seed testing and the importance of obtaining pure seed.

H. von Guttenberg gives the description of five species of
Cuscata and a key for their identification. Von Degen notes the
germination of dodder under varying conditions. Kinzel has made
a study of the effect of freezing seed and its bearing upon agri-
cultural weeds. Pieper discusses the method of testing the ger-
mination of seeds and presents a new method of determining the
germination of grass seed. Dorph-Petersen gives a summary of
seed tests carried on by the Danish Seed Control Station, during
which 9,024 samples of clover, grass, and other seeds were analyzed.
The paper gives a list of weed seeds found and includes notes on
germination and purity. F. G. Stebler, of the Zurich Seed Control
Station, Switzerland, gives the results of tests made of 10,335

HISTORY AND BIBLIOGRAPHY 829

seeds examined in 1908, with reference to adulteration, purity,
vitality, and the presence of Cuscuta. Vilke gives an account of
the presence of weed seeds found in Swedish seeds. J. Paczoski
notes the important weeds found in the Cherson Government.
A. Malzew reports on the more important weeds found in Russia;
black bindweed (Polygonum convolvulus) and corn cockle (Agros-
temma githago) were common in wheat; oats had, in addition, wild
oats (Avena fatua, glabrata), and Neshia panculata. In rye, the
black bindweed (Polygonum convolvulus), lamb’s quarters (Cheno-
podium album), stickweed (EHchinospermum lappula), and Neslia
paniculata were found. Lesage made a study upon the effect of
solutions of common salt and alcohol on the germination of garden
eress. O. Munerati and T. V. Zapparoli of Italy have made a
study of weed seeds with hard coats. F. Johnson and R. Hensman
discuss the source of the alien flora of Ireland through weed im-
purities found in agricultural seed. A. J. Ewart made tests of
various grass and garden seeds with reference to the vitality of
seeds after a sea voyage. In a lengthy report on the prolonged
vitality of seeds it was found that quite a per cent of seeds ger-
minated after half a century. Rees made a study of hard seeds
with reference to the cuticular layer. This layer repelled the water,
and for this reason seeds retained their vitality.

A recent paper by E. Lehmann on the temperature and lght
relations and the germination of seeds, gives both an exhaustive
summary of the subject and a great deal of original matter.

It is difficult to say under what conditions seed will germinate.
Older investigators regarded light as having no definite action on
the germination of seeds. Crocker found that the structure of the
seed coats retarded germination in the case of Xanthium. Shull,
Crocker, and others found that oxygen hastened the process. In
a recent paper by H. Lehmann, attention is called to the action of
light and temperature on the germination of seeds, both of which
influence this action. The seeds of Whitlavia grandtflora indicated
that germination is retarded at higher temperatures but not at
lower. He designates some seeds, such as H'pilobium rosewm, E. hir-
sutum (Lehmann), and Veronica peregrina (Heinricher) as light
germinating seeds. Dark germinating seeds are represented by
Phlox drummondii. Tehmann found that 4 per cent germinate in
light and 31 per cent in darkness. Maturity also influences ger-
mination of seed. When wheat is ripened at a lower temperature,
it requires a longer optimum temperature for germination than seed

830 WEED FLORA OF IOWA

ripened at a higher temperature. The seeds of blue grass when
planted soon after maturity did not germinate in darkness but
under the influence of light 88 per cent germinated. In spring,
however, the germination was equally good in darkness and light.

Cieslar found that light influenced germination. It would seem
from this and other investigations that structure, the oxygen, sub-
stratum moisture, temperature, light, in short, the ecology and
structure as well as physiology play an important part in germin-
ation.

There are many other contributions, but most of these papers
will be found recorded in the literature cited by Vandevelde, Harz
and Nobbe.

American work.—Connecticut.—The pioneer work in this coun-
try was done by Profs. E. H. Jenkins and Warneke, of the Con-
necticut Agricultural Experiment Station.

Miss Mary G. Jagger and E. H. Jenkins report the results of
analyses for 1908-1909-1910-1911, and note the character of the im-
purities of seed found in the Connecticut market.

North Carolina——Gerald McCarthy, of the North Carolina Agri-
cultural Experiment Station, published an elaborate paper on the
subject in which he gave the details of an extensive investigation
carried on in North Carolina on germination of seeds.

Michigan.—Some excellent work was done by Prof. W. J. Beal
who reported results of germination of clover seeds furnished by
seedsmen. From seeds grown on moist paper the results of the
germination showed that large red clover had a germination of
88 per cent, medium red clover 88 per cent, white clover 84 per
cent and alsike clover 64 per cent. Prof. Beal called attention to
the difference in germination of seeds when grown in sand and in
blotting paper. From seeds grown in sand the following results
were obtained: Medium clover had a germination of 76 per cent,
white clover 92 per cent, red clover (two separate lots) 70 and 56
per cent. :

A later report of Prof. Beal gives two tests of twelve years old
clover seeds in both of which the germination was 35.8 per cent.

Subsequent reports on the vitality of clover and other seeds were
also made.

Prof. Beal also reports tests on seeds sent by farmers. Fifty-
eight samples ranged from 25 to 97 per cent, seventeen being above
90 per cent. He early called attention to the presence of rib grass
in clover seed. Recently he has published an exhaustive bulletin
on the seeds of Michigan weeds with excellent figures made by

HISTORY AND BIBLIOGRAPHY 831

F. H. Hillman. Dr. R. Zceuw has published the results on the
comparative viability of seeds, fungi, and bacteria, when subjected
to various chemical agents. Ernest Bessey gives the results of seed
analysis for 1911 and 1912 from which it appears that buckhorn
and plantain were frequent. The paper gives the number of weed
seeds in a pound.

Mr. Parsons in 1893 made some interesting tabulations in a
summary of American seed vitality tests. In the results offered
by him we find the following: Alsike 72.7 per cent, crimson clover
59 per cent, red clover 84.8 per cent, mammoth clover 82.5 per
cent, white clover 72.1 per cent, alfalfa 61.6 per cent.

Pennsylvania.—Prof. Butz studied many hundreds of samples
of seeds, chiefly with respect to their germinative power. In many
cases the percentage of germination was very low. Thus we find
recorded the following: Alfalfa 52 per cent, alsike clover 61 per
cent, Japan clover 69 per cent and seradella 13 per cent.

Ohio.—Mr. Devol early recognized and emphasized the im-
portance of the experiment station in studying the viability of
seeds. In tests conducted by him clover showed a germination of
93 per cent. ;

Later Selby and Hicks made a study of fifty-two samples of
clover and alfalfa seeds sold in Ohio. They found not only that
the seeds had a low vitality but that they contained considerable
impurities.

Nevada.—Several very important papers have been published
by Mr. Hillman on clover seeds and their impurities. One of his
earlier bulletins deals with the descriptions of weed seeds and their
distribution, together with an incidental account of the occurrence
of these seeds in commerce. In a later publication he considers
the weed seeds found as impurities in various types of seeds, in-
cluding alfalfa, red clover, white clover, alsike clover, crimson
clover, Japan clover, Bokhara clover, yellow trefoil and esparcette.
In his investigations a large number of samples was examined.
The paper therefore gives a fair estimate of the impurities gen-
erally found in the various clover seeds offered for sale in this
country. ;

Kansas.—Prof. Roberts and Mr. Freeman carried on an extensive
investigation of alfalfa seed, showing adulteration, substitutes
and impurities; and the methods of detecting the latter. They
found some adulteration in alfalfa seed. The yellow trefoil
(Medicago lupulina) was most frequent though there were occa-

832 WEED FLORA OF IOWA

sional instances in which burr clover (Medicago denticulata) and
sweet clover (Melilotus alba) occurred. The most noxious weed
seeds found were the docks and the English plantain. The average
germination of alfalfa seed was 83 per cent. The subject is also
briefly discussed by Ten Eyck.

Prof. Roberts and Mr. Freeman also made quite an exhaustive
study of the grass seeds commonly sold in Kansas. The dodder
may prove to be a destructive clover parasite in the United States.
Mr. Brown, in a paper on legal and customary weights per bushel
of seeds, has also brought together much important matter on the
subject of the weight of commercial seeds.

Maine.—Prof. Harvey and other members of the staff of the
Maine Experiment Station investigated the vitality and the im-
purity found in the agricultural seeds offered for sale in that
state. The results of Prof. Harvey’s investigations disclosed the
advisability of having a law to regulate the sale of seeds. Such
a law was passed by the state of Maine and the work of carrying
on this law was placed in the hands of the director of the Station.

The results of the tests and regulations concerning the seed
testing for Maine were published by Charles D. Woods, director
of the Station. In a subsequent bulletin he discusses seed inspec-
tion and lists 79 kinds of weed seed. With Hammond the require-
ments of the law are given as well as results of seed testing.

Minnesota.—W. L. Oswald, Bulletin 127 of the Minnesota Station
gives the results of purity and germination tests for 1275 samples
of commercial seed.

North Carolina—McCarthy in an early bulletin of the North
Carolina Station reported on the analyses of seed in 1912. O. I.
Tillman reported on the analyses of commercial seed in accordance
with the North Carolina pure seed act.

Kentucky.—Prof. Garman and others, of the Kentucky Experi-
ment Station, have investigated the impurities in grass and other
forage plants sold in Kentucky. It was found that thirty-six of
the five hundred samples examined were adulterated; among these
were red clover, blue grass, timothy and orchard grass. They con-
cluded that the greatest fraud perpetrated is in the sale of certain
varieties under an assumed name. In several publications Prof.
Garman discussed the impurities and adulterations of grass seed
sold in Kentucky and recommended that no field seeds should be
sold in Kentucky containing more than 5 per cent weed seeds.
He also gave a comprehensive account of seed testing apparatus

HISTORY AND BIBLIOGRAPHY 833

and the conditions under which germination tests are made, with
special reference to work in Kentucky.

Kentucky now has-in consequence of this work an admirable
law forbidding adulteration or misbranding of the clovers and
timothy sold for seed in the state. Its effects have been most
salutary and have been studied with profit by other common-
wealths.

Vermont.—Mr. L. W. Barton, under the direction of Profs.
Jones and Orton of the Vermont Experiment Station, made an
examination of thirty-four samples of clover seed in Vermont. He
reports the total percentage of impurities in red clover as being
from .3 to 5.3, with an average of 1.8 per cent; alfalfa as having
a maximum of 7.1 per cent and a minimum of .6 per cent. Sorrel
was found in 60 per cent of the red clover samples and wild carrot
in a few, the rib plantain occurred in 77 per cent, dodder in 5
per cent, and Canada thistle in 5 per cent. Dodder did not occur
in the alfalfa, but in 8 per cent of the samples Canada thistle
was found.

Massachusetts.—G. E. Stone reports on seed tests made in 1908
and 1910. Smith, Chapman, and Stone describe fourteen weed
seeds most commonly found in grass seed and cattle foods, with a
brief account of the weeds of the state.

Maryland.—E. I. Oswald made a series of experiments to deter-
mine the vitality of seeds when placed in manure under different
conditions. It was found that weed seeds when left for six months
in manure had lost their vitality completely. When left there for
one month under conditions usually followed by dairymen, the
seeds of ribgrass, horse nettle, dock, and a few others were still
firm. Mention of weed seeds is made in the treatise by J. B. S.
Norton on Maryland weeds. The same author gives the result of
seed analysis of various commercial seed.

Nebraska.—E. M. Wilcox in a paper on dodder in alfalfa seed
discusses the frequency of the impurities and means of eradicating
the weed.

New Hampshire.—F.. W. Taylor in reports of seed tests for 1910
and 1911 discusses the New Hampshire law giving results of purity
and germination tests.

New York—F. C. Stewart under the head of alfalfa troubles
discussed dodder in alfalfa seed and subsequently gave a method

of screening dodder out of alfalfa seed. In 1910 G. T. French re-
53

834 WEED FLORA OF IOWA

ported on an examination of several hundred samples of seed with
special reference to the occurrence of dodder, Russian thistle, and
Centaurea repens; an earlier report by the same author reported
on seed tests made at the station. Further discussion is found in
the New York Agricultural Experiment Station Circular 8:1-4,
Dodder in Alfalfa, by F. C. Stewart and G. T. French. Mr. M.
T. Munn in Bulletin 362 gives the seed tests made in 1912, giving
results of examinations made for purity of commercial samples.

North Dakota.—H. L. Bolley discussed the pure seed law of
North Dakota and seed work ending December 31, 1909, with an
account of weed seeds found.

Wisconsin.—A. L. Stone in a circular of information discussed
the seed inspection law of the state, adding some general informa-
tion. With G. T. Moore he also discussed the question of the eradi-
cation of farm weeds which have been introduced by means of im-
pure seed.

Mr. George T. Harrington discussed the worst weeds in connec-
tion with grass and clover seeds. D. L. Beach made a study of
commercial feeds with reference to the germination of weed seeds
found in these feeds. Feed subjected to steaming before feeding
contained no germinable weed seeds.

Texas.—According to O. M. Ball alfalfa seed sold in Texas con-
tains the following chief impurities: Russian thistle, ribgrass,
tumbleweed, pigweed, two kinds of dodder, green foxtail, curled
dock, bur clover, and sweet clover. The vitality varied from 49.5
to 96.5 per cent. A subsequent report also on alfalfa seed was
made.

Arizona.—Prof. Thornber made an examination of alfalfa seed
sold in Arizona. This showed a high percentage of germination.

Iowa.—The Iowa Agricultural Experiment Station has produced
several publications relating to weed seeds. Ball discussed im-
purities in grass seed; Pammel, Buchanan and King have pub-
hshed a bulletin covering impurities of commercial seed. Two
bulletins by I. H. Pammel and Charlotte M. King, ‘‘Results
of seed investigations for 1907’’ and ‘‘Results of seed investiga-
tions for 1908 and 1909,’’ give the results of analyses of seed sent
by farmers to the Station. The results of the 1907 investigation
indicated that the weed seeds were different in many cases from
those reported in a previous publication; dropseed grass was
common, occurring in 3.3 per cent of the samples; Canada thistle
seed was also less frequent. The investigations for 1908-1909 in-

HISTORY AND BIBLIOGRAPHY 835

dicated that the seed sold in the state has improved, field tests of
germination were lower than laboratory tests. A method of deter-
mining the vitality is also given. The subject of delayed germina-
tion is discussed by H. S. Fawcett, who found that a relationship
exists between the hardness of the seed coat and the dormant
period. L. H. Pammel states that different conditions influence
the germination of seeds, such as hard coats and freezing of seeds.
The delayed vitality of weed seeds is discussed by L. H. Pammel
and Charlotte M. King. Weed seeds after freezing germinate
more readily when frozen.

Work of the United States Government.—The National Govern-
ment began a serious investigation of agricultural seeds and their
impurities in 1893. Early articles on the subject appeared under
the head of ‘‘Pure Seed Investigations.’’

Mr. Hicks called attention to the abuses in the seed trade. The
matters that were mentioned by him have evidently not been
remedied since 1894. Since then the work of the Department has
been immeasurably increased, especially by such contributions as
have been made by Mr. Duvel on the vitality of buried seeds and
the storage and germination of wild rice; and the paper by Mr.
Pieters on ‘‘The Farmer’s Interest in Good Seed.’’ Among the
notes on seed testing in 1897, Prof. Hicks and Mr. Sothoron Key
published an account of the germination of several forage plants
and flower garden seeds.

A good table on the percentage of germination sanders re-
quired of seeds will be found in a paper by Mr..Pieters. These
seed standards were also published in the Year Book of 1896. Later
Mr. Pieters discussed the presence of clover dodder and other im-
purities in clover seed. In a circular by Prof. Dewey of the same
division the dodders found in clover were discussed.

The quality of the seed, especially its germinative energy, de-
pends somewhat on the manner in which seeds are kept. Two ar-
ticles on this subject are of special interest in this connection, one
by Pieters, ‘‘Agricultural Seeds, Where Grown and How to
Handle,’’ and an article by Pieters and Brown, ‘‘Kentucky Blue
Grass Seed, Harvesting, Curing and Cleaning.’’

The United States Department of Agriculture has published
rules and described apparatus for seed testing. These were adopted
by the standing committee on seed testing of the Association of
American Agricultural Colleges and Experiment Stations.

836 WEED FLORA OF IOWA

In reports of more recent work, A. F. Woods found dodder seed
frequent in alfalfa and red clover seed. The adulteration and mis-
branding of alfalfa, red clover and grain seeds was discussed by
W. A. Taylor and B. T. Galloway. F. H. Hillman in several papers
on the impurities, adulteration, etc., of clover and forage plant
seeds and vetches, presented admirable figures and good descrip-
tions of weed seeds found as impurities. Westgate, McKee, Evans,
and Vinall gave a brief account of impurities found in alfalfa seed
and sweet clover. The subject of low grade clover seed was con-
sidered by Edgar Brown and Miss Crosby.

In a paper by Brown and Hillman, ‘‘The Seed of Red Clover
and its Impurities,’ the more important impurities found in Eu-
ropean and American grown clover seed are given. Attention is
called to the introduction of bad seeds from Chile. In 1905 two
hundred and seventy-five thousand pounds of Chilean red clover
seeds were imported into the United States, and this clover seed
contained Chilean clover dodder seed.

Canadian work.—In 1892 Prof. J. H. Panton called attention to
the importance of making an investigation of seed purity and of
carrying on a campaign for better and cleaner seed. He thought
a large number of the weeds on the Ontario farms were introduced
in clover seed.

He found the number of weed seeds varied greatly, all the way
from one to four thousand five hundred and forty per half ounce.
Among the weed seeds he reported several that have become trouble-
some in the Mississippi valley; these include ribgrass and chicory.

Saunders in several reports of the Experiment Farms has dis-
cussed the vitality of grass and clover seeds. In 1903 there were
tested one hundred and eighty-six samples of clover. The highest
percentage of germination was low, the lowest 17 and the average
76.3. A large number of grass seeds were also tested. The work
has been continued by Saunders and Grisdale (1910) relative to
determining the climatic conditions favorable to high vitality of
seeds.

Since 1903 the Department of Agriculture of the Dominion of
Canada has created a seed division with Mr. G. H. Clark in charge
of the work in purity and vitality tests.

A very notable publication on the subject of weeds and weed
seeds has been contributed by Clark and Fletcher who have given
colored illustrations of the more important impurities found in
clover and other seeds.

HISTORY AND BIBLIOGRAPHY 837

A. B. McCready of the Ontario Agricultural College gives the
results of germination tests of alfalfa and clover in which the
superiority of bright, clean seed is shown.

Australia.—A. J. Ewart made tests of various grass and garden
seeds with reference to the vitality of seeds after a sea voyage. In
a lengthy report on the prolonged vitality of seeds it was found
that quite a per cent of seeds germinated after half a century.
Rees made a study of hard seeds with reference to the cuticular
layer. This layer repelled the water and for the same reason seeds
retain their vitality.

BIBLIOGRAPHY.
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838 WEED FLORA OF IOWA

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HISTORY AND BIBLIOGRAPHY 839

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Weeds in general ; two newcomers into Pennsylvania [ Allium
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boc. | 1902.

Budd, J. L. The Russian thistle in its natal home. Bull. Ia. Agr.
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Buettner, R. Flora advena mordica. ay Verh. Botan. Ver. Bran-
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Bull, C. P. Weeds in flax fields. Cy. of Am. Agr. 2:299.

Burtt-Davy, Joseph. Dodder in luzerne. Transvaal Agric. Jour.
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Four noxious weeds [Burweed, cocklebur, Mexican poppy,
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Some injurious weeds. Trans. Agr. Jour. 3:291-299. Abs.
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Cates, J. S., and Cox, H. R. The weed factor in the cultivation of
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Clark, G. H., & Fletcher, Jas. Farm weeds of Canada. With il-
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Clinton, G. P. The Russian thistle and some plants that are mis-
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Cockerel, T. D. A. Some western weeds and alien weeds in the
west. Bot. Gaz. 20:503-504. 1895.

Coit, J. E., and Packard, W. E. Imperial Valley settlers’ crop
manual. Bull. Cal. Agr. Exp. Sta. 210:139-253.

840 WEED FLORA OF IOWA

Cotta, H. Forstrath in Tharand—auf der kleinen Zillbach einen
Hennebergschen Forsthause am 30. Oct. 1763. 25 p. Tharand
1844.

Cook, L. C. Questions concerning weed distribution. Bull. Vt.
Bot. Club. 3 :14-15.

Covile, F. V. Noxious weeds. Rept. U. S. Dept. Agr. 1890:
388-392.

Craig, Moses. The farmers’ foes. (Thistles.) Bull. Ore. Agr.
Exp. Sta. 32 :99-115.

Some Oregon weeds and how to destroy them. Bull. 19:21.

Crosby, J. O. Incursion of weeds into our gardens and farms.
Trans. Ia. St. Hort. Soe. 42 :153-154.

Cryer, J): Hawkweeds. Naturalist. 1909: 143-144.

Cusick, Wm. Forest Fires in Oregon. | Refers to introduction of
Epilobium spicatum or ‘‘Elkweed.’’| Bot. Gaz. 8:176.

Darlington, Wm. American weeds and useful plants. Rev. Ed.
460. New York, 1859.

Dewey, L. H. Distribution of prickly lettuce in the United States.
Bot. Gaz. 21 :34-35.
Migration of weeds. Yrbk. U. S. Dept. Agr. 1896: 263-285.
Table of two hundred weeds. Yrbk. 1895 :594-611.
Twenty-five most harmful weeds. Yrbk. 1897 :641-645.

Dodson, W. R. Rice weeds in Louisiana. Bull. La. Agr. Exp. Sta.
77 :394-429. Note in Ex. Sta. Ree. 16:168.

Ehrhart, F. Beitrage zur Naturkunde und den damit verwandten
Wissenschaften, hesonders der Botanik, Chemie, Haus und
Landwirtschaft, Arzneigelehrtheit und Apothekerkunst. 7
pt. 1293. Hannover und Innsbruck, 1787-1792.

Oekonomische Pflanzenhistorie nebst dem Kern der Land-
wirthschaft, Garten-u. Arzneikunst. 12. Ulm and Mem-
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Ewart, A. J., and Tovey, J. R. Californian Stinkweed, or sheep-
weed (Glia squarrosa H. & A.). Jour. Dept. Agr. Victoria.
VI:592.

The Thorn Apple, Ib. 11:672.

Ewart, A. J. The proclaimed plants of Victoria. Jour. Dept.
Agr. Victoria. 5:28, 104, 230, 276, 336, 438, 498, 540, 606,
680, 720. Abs. in Just’s Bot. Jahrb. 22:610.

Fernald, M. L. Some recently introduced weeds. ‘Trans. Mass.
Hort. Soe. 1905: 11-22.

?

HISTORY AND BIBLIOGRAPHY 841

French, C. An introduced weed (Hypericum perforatum). Jour.
Dept. Agr. Victoria. 1903: 65-67.

Garcke, August. Illustrierte Flora von Deutschland. 795. Ber-
lin, 1903.

Gleditsch, J. G. Systematische Einleitung in die neue Forstwissen-
schaft. 544. Berlin, 1775.

Gmelin. J. F. Abhandlungen von dem Arten des Unkrauts auf
den Aeckern in Schwaben. 408. Lubeck, 1779..

Goff, E. S. Noxious weeds. Bull. Wis. Agr. Exp. Sta. 39:38.

Noxious weeds of Wisconsin. Bull. 76:52.
The Russian thistle. Bull. 37:13.
Gray, Asa. Burs in the Borage family. Am. Nat. 10:4.
Pertinacity and predominance of weeds. Am. Jour. Sci.
18 :161-167. Also in Scientific Papers. 2:234-242.

Greene, E. L. Is Rhus glabra in Canada? Ottawa Nat. 22:179-181.

Greif, O. Queckenvertilgung. Mitt. Deutsch. Landw. Ges. 1906:
339. Abs. in Just’s Bot. Jahrb. 9 :482.

Haglund, E. Characteristic weeds on cultivated marsh soils. See
Svenska Mosskultur for Tidskr. 25: 238-245. Note in Exp.
Sta. Ree. 26 :538. ;

Halstead, B. D. American and English weeds compared. PI.
World. 3:171-173.

Our worst weeds. <A scale of points. Proc. Soc. Prom. Agr.
Sci. 10 :43-49. |

Preliminary list of Iowa weeds. Bull. Dept. Bot. Ia. Agr.
Coll. 1888: 36-54. : .

The weeds of New Jersey. Agr. Rept. N. J. Agr. Exp. Sta.
1890: 370-453.

Harper, R. M. Some native weeds and their probable origin.
Bull. Torr. Bot. Club. 35 :347-360. 1908.

Harrison, F. C. Weeds of Ontario. Ont. Dept. Agr. 80. Toronto,
1900. ;

Harrison, F. C., & Lockhead, W. Some common Ontario weeds.
Bull. Ont. Agr. Col. & Exp. Farm. 128:96.

Hartig, Theodor. Vollstaéndige Naturgeschichte der forstlichen
Kulturpfianzen Deutschlands. 584. Berlin, 1851.

Harvey, F. L. Maine weeds. Rept. Me. Agr. Exp. Sta. 1891:
179-181.

Three troublesome weeds. Bull. Me. Agr. Exp. Sta. 32:8.

842 WEED FLORA OF IOWA

. Hays, W. M. The Russian thistle or Russian tumble weed. Bull.
Minn. Agr. Exp. Sta. 33:15.

Weeds in our fields. Bull. 46 :373-382.

Henderson, L. T. Twelve of Idaho’s worst weeds. Bull. Idaho
Agr. Exp. Sta. 14:91-136.

Hill, E. J. Notes on Migratory weeds. Bull. Torrey Bot. Club.
29 :564.

Hillman, F. H. Nevada weeds. Bull. Nev. Agr. Exp. Sta. 21:15;
22 :11.

Nevada weeds; Nevada and other weed seeds. Bull. 38:1381.

Hitchcock, A. 8., & Clothier, G. L. Reports on Kansas weeds.
Bull. Kan. Agr. Exp. Sta. 50:19-54; 52:87-101; 57:64;
66 :19-54; 76:23; 80:113-164.

Horton, H. E. Weeds and farming in the Northwest. Farm Weeds.
1909 (Apr.) 6-10.

Howitt, J. E. The perennial sow thistle and other weed pests of
1908. Bull. Ont. Dept. Agr. 168 :24.

Weeds of Ontario, Bull. 188:144. 206f. 1911.

Hundeshagen, J. G. Lehrbuch der Forst u. landwirthschaftlichen
Naturkunde. 372. Tibingen, 1829.

Jenkins, E. H. Weeds, feeds and seeds. Bull. Conn. Agr. Exp.
Sta. 161 :6.

Jones, L. R., and Morse, W. J. The shrubby cinquefoil as a weed.
Rept. Vt. Agr. Exp. Sta. 1903: 173-190.

Jones, L. R., & Orton, W. A. Notes on certain threatening weeds.
Bull. Vt. Agr. Exp. Sta. 16 :169-173.

Notes on Vermont weeds. Bull. 11:219-228.
Orange Hawkweed, or ‘‘Paint-brush.’’ Bull. Vt. Agr. Exp.
Sta. 56:15. ;

Kabsch, W. Das Pflanzenleben der Erde. 642. Hannover, 1870.

Kalter, Grace M. The weeds of the Miami Valley. Cont. Bot. Lab.
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Knowlton, C. H. Two introduced plants [Brassica hirsuta and
Bromus inermis in southern Massachusetts]. Rhodora 11:
120-121.

Krafft, Guido. Pflanzenbaulehre.

Lamson-Schribner, F., & Newman, C. L. Weeds on the farm.
Bull. Tenn. Agr. Exp. Sta. (v. I) 3:29-52.

Langethal, C. E. Lehrbuch der landwirthschaftlichen Pflanzen-
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HISTORY AND BIBLIOGRAPHY 843

Lazenby, W. R. The weedy plants of Ohio. Proc. Soc. Prom. Agr.
Sei. 7 :42-47.

Long, H. C. Some troublesome weeds. Yrbk. Farm and Home.
1910.

Lloyd, F. EK. A Perea a dodder. Pl. World, 11:40-41; 12 :65-66.

Long, H. C. Weeds and their destruction. Trans. Highland and
Agricultural Soc. Scotland. 5, Ser. 238:45-83. 1911.

Long, H. C., and Percival, J. Common weeds of the farm and
garden. London, 1910. XVIII and 461.

McCready, S. B. Weeds in Ontario in 1908-9. Ann. Rept. ‘On-
tario Agr. Col. & Expt. Farms. 35 :37-40.

Maiden, J. H. Hexham scent. (Melilotus parviflorus) identical
with King Islands Melilot (UM. officinalis) Farmers beware!
Agric. Gaz. N. 8. W. 18 :929-930.

‘*Poison Ivy.’’ Abst. Proc. Roy. Soc. N. S. W. 1908.
Nov. 4.

The weeds of New South Wales. A pigweed, Amaranthus
viridis, Agric. Gaz. N. 8. W. 18:797-798. Ribgrass or Plantain.
19 :573-574.. Tumbleweed. 19:1070.

Malzew, A. On weed seeds in the grains found on the markets of
the province of Tscheljabinsk, Orenburg government, Russia.
Trudy Byuro Prickl. Bot. (Bul. Angew Bot.) 4:231-255; 19 pl.
Abs. in Exp. Sta. Rec. 26 :135. Sh eae

The spread of the important weeds in Russia. (Distribution
of 162 weeds discussed.) Ex. Sta. Rec. 23:40. Trudy eee
Prikl. Bot. 2:251-312, 595-664.

Menault, E., and Rousseau, H. Les plantes misibles en cule
et en horiicaleure 214. Paris, 1902.

Millspaugh, C. F. Descriptive list of the weeds of West Virginia.
Bull. W. Va. Agr. Exp. Sta. 23 :215-310.

Your weeds and your neighbors.. Bull. W. Va. ie Sta.
12 177-212; 19 :121-127.

Moesz, G. On some introduced plants in Hungary. Botanikai
Kozlemenyek 8:136-147. 1909. German Abst. 38-43.. Abst.
Bot. Centrbl. 113:53. 1897.

Mundy, H..G. The spread of injurious weeds... Transvaal Agr.
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Munson, W. M. Dandelions and Hawkweeds. Bull. Me. Agr. Sta.
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Neilreich, August. Flora von Wien. 706. Vienna, 1846. Neate
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844 WEED FLORA OF IOWA

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Nelson, Aven. Squirreltail grass (Foxtail), one of the stock pests
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_ The worst weeds of Wyoming. Bull. Wyo. Agr. Exp. Sta.
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_Norton, J. B.S. Maryland weeds and other harmful plants. Bull.

Md. Agr. Exp. Sta. 155:71. 56f.

Osborne, O. M. Weed pests of Idaho and methods of eradication.
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—Ostenfeld, Hansen C. Nogle ny-indslabte Planter Bot. Tids. 19:
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Denmark.

Oswald, W. L. and Boss, Andrew. Minnesota weeds. Series I. De-
scriptions and identifications by W. L. Oswald and Eradication
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Paczoski, J. Field weeds of the Cherson government. Trudy Byuro
Prikl. Bot. (Bul. Agnew Bot.) 4:71-146. 1911. Abs. in Exp.
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Pammel, L. H. Canada Thistle. Pr. Bull. Ia. Agr. Exp. Sta.
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Horse Nettle as a troublesome weed in Iowa. Bull. Ia. Agr.
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Noxious weeds. Bull. Ia. Agr. Exp. Sta. 28 :199-214.

The problem of weeds in the West. Cont. Bot. Dept. Ia.
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Quack and wheat grasses. Bull. Ia. Agr. Exp. Sta. 83:
397-416.

Some troublesome weeds of the mustard family. Bull. Ja.
Agr. Exp. Sta. 35 :656-686.

Some weeds of Iowa. Bull. Ia. Agr. Exp. Sta. 70 :297-531.

The thistles of Jowa and notes on a few other species. Proce.
Ta. Acad. Sei. 8:26,

Two other troublesome weeds. (European bindweed and
Ground burnut). Bull. la. Agr. Exp. Sta. 42 :187-139.

Two noxious weeds. Bull. Ia. Agr. Exp. Sta. 28:199-214.

Weed pests. Bull. Ia. Agr. Exp. Sta. 13:72-75.

HISTORY AND BIBLIOGRAPHY 845

Weeds of corn fields. Bull. Ia. Agr. Exp. Sta. 39 :27-52.

Weeds of pastures and meadows. Bull. Ia. Geol. Sur. I:
448-463.

Weeds of southwestern Wisconsin and southeastern Minne-
sota. 20. St. Paul, 1887.

Pammel, L. H., and King, C. M. Notes on eradication of weeds
with experiments made in 1907 and 1908. Bull. Ia. Agr. Exp.
Sta. 105 :265-300. :

Parish, E. B. The vegetation of Plymouth 300 yrs. ago. Rhodora.
3:17.

Parish, 8. B. Notes on some introduced plants of southern Cali-
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Pease, A. Certain railroad weeds of northern New Hampshire.
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Petersen, N. F. Flora of Nebraska. 217, Lincoln, Neb., 1912.

Piper, C. V. Pernicious weeds among emigrants. Yrbk. U. S.
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Prentiss, A. M. Weeds (Hawkweed and Beard-tongue). Bull.
Cor. Agr. Exp. Sta. 37:366-371.

Ratzeburg, J. T. C. Die Standortsgewachse und Unkrauten
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und Landwirthschaft und zu andern Fachern. 487. 12 tab.
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Reum, J. A. Grundriss der deutschen Forstbotanik. Ed. 2. 489.
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Romer, F. Zur Flora advena von Polzin in Hinterpommern.
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Zur Flora von Kolberg in Hinterpommern. Verhandl. Bot.
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Sayre, L. E. Loco weed. Trans. Kan. Acad. Sci. 18:141-144.
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Schultz, G. Charlock and white radish. Arb. Deut. Landw. Gesell.

1909: 78 (No. 158). Abs. in Exp. Sta. Ree. 23::732.

Selby, A. D. A first Ohio weed manual. Bull. Ohio Agr. Exp.

Sta. 83 :249-400.

A second Ohio weed manual. Bull. 175 :191-274.

The Russian thistle in Ohio and weeds in general. Bull.
55 :33-69.

Smith, W. G. A hundred Yorkshire weeds. Yorkshire Col. & E.
& W. Ridings Joint Agr. Council. 12.

846 WEED FLORA OF IOWA

Sorauer, P. Unkrauter. See Pflanzenkrankheiten 2 :894-904.

Spillman, W. J. Weeds in timothy and clover meadows. Oy. of
Am. Agric. 2 :447.

Sturtevant, E. L. Geographical distribution of plants. (Mentions
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Thellung, A. Zwei kleine Beitrage zur Adventivflora Deutsch-
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Thorne, C. E. A pestiferous weed (wild lettuce). Bull. Ohio Agr.
Exp. Sta. 44:141-146.

Thornton, R. W. The Khakibush (Aplopappus sp.) another noxious
weed. Agric. Jour. Cape of Good Hope. 30:76-78.

Tolf, R. Weeds on Swedish Moor plantations. Svenska Mosskultur
for Tidskr. 17:428-440. Abs. in Exp. Sta. Rec. 16:61.

Tourlet, E. H. Catalogue des plantes vasculaires du departement
d’Nidre-et-Lorre. 621. 1908.

Vasey, G. W. Weeds of agriculture. Rept. U. S. Dept. Agr.
1886: 84-93.

Voelcker, J. A. Weed seed in fertilizer. See Jour. Roy. Agr.
Soe. 63 :274.

Waddell, C. H. On.some Irish hawkweeds. Irish Nat. 18 :149-150.

Waldron, C. B. The mustard family. Bull. N. D. Agr. Exp. Sta.
IMG) 2119).

Troublesome weeds of the mustard family. Bull. 6:19.

White, P. J. Orange Hawkweed or Paint-brush. Cir. Cor. Agr.
Exp. Sta. 9:10-12.

Whitson, A. R., et al. On weeds of the cranberry marshes. Ann.
Rept. Wis. Agr. Exp. Sta. 1904: 233-237.

Wilson, James. Russian thistle. Bull. la. Agr. Exp. Sta. 26:7.

Wollny, E. Untersuchungen iiber den Einfluss der Unkrauter auf
das Wachstum der Kulturpfianzen. Forsch. auf Gebiete der
Agrikulturphysik. 7:342. 1884.

Wooten, E. O. New Mexico weeds. Bull. N. M. Agr. Exp. Sta.
18 :36.

The Russian thistle. Bull. 16:20.

ERADICATION OF WEEDS.

Adams, G. E. Weeds; their eradication and control. Bull. R. I.
Agr. Exp. Sta. 133 :51-61.

Aderhold, R. An experiment on the eradication of weeds in
meadows. Centrbl. Bakt. u. Par. 2 Abt. 7:662. 1907. Abs.
in Exp. Sta. Ree. 13 :658.

HISTORY AND BIBLIOGRAPHY 847

Alice, G. Control of weeds in rice fields. Abs. in Internat. Inst.
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Anonymous. On eradication of weeds. See Rept. on ri Sta.
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Weed pests; Agr. Bul. Straits and Federated Malay States
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Bailey, L. H. Eradication of weeds by crop rotation. Cy. of Am.
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Weeds and the management of them. Cy. Am. Agr.
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Bamber, M. K. The cultivation of Passiflora foetida and Mikania
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_ Bersch, W. Handbuch der Moorkultur. XII:288; 8 pls., 4/f.
Vienna and Leipsic, 1909 (Contains matter on weed control).

Bessey, C. E. Poisonous weeds. Rept. Neb. Agr. Exp. Sta. 1902:
14-62.

The Russian thistle. Bull. Neb. Agr. Exp. Sta. 31:67-77.

The Weeds of Nebraska. Proc. Soe. Agric. Sci. 14:33-44.

Bolley, H. L. Canada thistle: means of holding it in control.
Pr, Bull. N. D. Agr. Exp. Sta. 28:5.

The destruction of weeds in cereal crops by means of solu-
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Means of eradicating dandelions on parks, lawns, roadsides
and meadows. Pr. Bull. N. D. Agr. Exp. Sta. 26:4.

On eradication of weeds. See Rept. N. D. Agr. Exp. Sta.
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On the use of chemical sprays in destroying mustard, king-

~ head, and other weeds in cereal grain fields. Pr. Bull. N. D.
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Quack grass and how to hold it in ghee. Pre pulleNe Ds
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Weed control by means of chemical sprays. Proc. Am. Soc.
Agron. 1.

Weed control by means of chemical sprays. Bull. N. D.
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Weeds and methods of eradication. Bull. N. D. Agr. Exp.
Sta. 80 :513-540.

848 WEED FLORA OF IOWA t
e

Boss, Andrew L. Minnesota weeds. Eradication. See Bull, Minn.
Agr. Exp. Sta. 129.

Bruce, W. Report on charlock spraying. Edinburgh and east of
Scotland Col. Agr. Bul. 3:10. 1904. Abstract in Ex. Sta. Rec.
16 :884.

Bruckner, W. The extermination of thistles. Ztschr. Landw.
Kammer. Schlesien. 15:750, 751.

Burrill, T. J. Canada thistles and their extermination. Bull. II.
Agr. Exp. Sta. 12 :379-387.

Carruthers, Wm. On eradication of weeds, see, Ann. Rept. Con-
sulting Bot. Roy. Agr. Soc. Eng. 68:222-225; Rep. for 1909;
7:353. Jour. Roy. Agr. Soc. Rep. for 1902, 62:249-256;
63 :279-288.

Cazaux, L. A new method for the destruction of mustard. Prog.
Agr. et Vit. (Ed. L’ Est) 25:556-557. 1904.

Cox, H. R. The eradication of bindweed or wild morning-glory.
Far. Bull. U. S. Dept. Agr. 368 :19.

Crane, P. B. Quack grass eradication. 114. St. Paul, 1910.

Danger, L. Unkrauter und pflanzliche Schmarotzer, Ein Beitrag
zur Erkenntniss und Bekampfung desselben fur Landwirte
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Dewey, L. H. Weeds and how to kill them. Far. Bull. U. 8. Dept.
Agr. 28:32. .

The Russian thistle; its history as a weed in the United
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Eaton, A. J., and Edson, H. A. A practical method of lnlling
witch grass. Bull. Vt. Agr. Exp. Sta. 149 :419-447.

Foultes, P. H. Destruction of thistle. Jour. Roy. Agr. Soc. Eng.
70 :422-423.

Garman, H. The broom rapes. Bull. Ky. Agr. Exp. Sta. 105:32.

Glover, G. H. The poison weed problem in the arid west. Am.
Vet. Rev. 34:493-502.

Gmelin, J. F. Abhandlung yon den Arten des Unkrauts auf den
A. Ackern in Schwaben. 408. Lubeck, 1779.

Greene, M. L. Among school gardens. 388. 24 pl., 81 f. New
York, 1910.

Griffiths, D. A protected range in Arizona. Bull. U. S. Dept.
Agr. Bur. Pl. Ind. 177:28.

Range conditions in Arizona. Bull. U. 8. Dept. Agr. Bur.
Pl. Ind. 67:863. Abs. in Ex. Sta. Rec. 16:863.

HISTORY AND BIBLIOGRAPHY 849

Gussow, H. T. War against weeds. Yrbk. Farmer and Stock-
breeder. 1908.

Haglund, H., and von Teilitzen, H. On the eradication of weeds
by spraying with iron sulphate solution. Svensk. Mosskult.
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Halsted, B. D., and Kelsey, J. A. Experiments with weeds. Ann.
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Hitier, H. The destruction of wild mustard. Jour. Agr. Prat.
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Hogenson, J. C. A weeder harrow for dry farming. Far. Bull.
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Holtz, F. L. Weeds; Nature Study Rev. 1910: 237-245. Abs. in
Exp. Sta. Rec. 24:55.

Johnson, A. G. Canada thistle and its eradication. Cir. Pur. Agr.
Exp. Sta. 32:12.

Jones, L. R. Chemical weed killers or herbicides. Cy. of Am.
Agri. 2:115-118.

Killing weeds with chemicals. Rept. Vt. Agr. Exp. Sta.
12 :182-188.

Jones, L. R.,.and Morse, W. J. The shrubby cinquefoil as a weed.
Rept. Vt. Agr. Exp. Sta. 1903: 173-190.

Jones, L. R., and Orton, W. A. The orange Hawkweed or ‘‘ Paint-
brush.’’ Bull. Vt. Agr. Exp. Sta. 56:15.

Juhlin-Dannfelt, H. Hquisetum palustre and its eradication.
R. Landt. Akad. Handl. Och Tidskr. 42 :335-339. 1903. Abs.
in Ex. Sta. Rec. 16:61.

Kirk, T. W. Celery-Leaved Buttercup. N. Z. Dept. Agr. Leaf.
for Farmers. 46:2.

Sheep’s Burr. Australian ifr (Acaena ovina). N. Z.
Dept. Agr. Leaflet for Farmers. 74:4.

Korsoms, E. The weed problem: Some observations and experi-
ments. Tidskr. Norske. Landbr. 10:247-280; 295-330. Abs.
in Ex. Sta. Ree. 15:683, 34 page. .

Kraus, O. The common toad flax. Arb. Deut. Landw. Gesell.
199 :5-23. (No. 166.)

Larsen, O. H. Report of co-operative variety tests and fertilizer
experiments. Zealand, 1910. (Includes work on eradication
of weeds.) Ber. Landbr. for. Virks. Planteavl. Sjaalend. 1910:
404,

Laubert, R. Ambrosia artemisiaefolia Linne ein interessantes
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54

850 WEED FLORA OF IOWA

Long, H. C. The destruction of weeds by chemical means. Sci.
Amer. Sup. 71. 1911. Nov. 1832. 93, 94.

Weeds and their destruction. Trans. Highland and Agri-
cultural Soc. Scot. 5th ser. 23:45-83. 1911.

M’Alpine, A. N., and Wright, R. P.. Weeds and weeding. Trans.
Highland and Agricultural Soc. of Scotland. 5th ser. 6:1894.

McCready, S. B. On weed introduction and methods of eradica-
tion. Ann. Rept. Ontario Agr. Col. and Expt. Farm. 36 :35-37,
39-42. 1910.

Spraying tests and seed investigations. Ann. Rept. Ont.
Agr. Col. and Expt. Farm. 35 :42-48. 1909.

MeNair, A. D. Obnoxious weeds in Lespedeza and their eradica-

tion. Bull. La. Agr. Exp. Sta. 180 :38-43.

Marre, EK. Experiments in the destruction of wild mustard and
wild radishes. Semaine Agr. 21:358-359. 1901. Abs. in Ex.
Sta. Ree. 13 :658-659.

Millspaugh, C. F. Weeds as fodder for stock. Chemical weed ex-
termination. Bull. W. Va. Agr. Exp. Sta. 22 :177-212.

Moore, R. A., and Stone, A. L. The eradication of farm weeds
with iron sulphate. Bull. Wis. Agr. Exp. Sta. 179 :3-17.
Moore, R. A., Stone, A. L., and Hutton, G. Eradication of farm
weeds. Ann. Rept. Wis. Agr. Exp. Sta. 1907: 411, 412.
Nobbs, H.-A. Dodder Cuscuta and its eradication. Agric. Jour.

Cape of Good Hope. 30:725-781.

Experiments upon the destruction of prickly pear. 1907.
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Nobbe, F., and Simon, J. Concerning the change of hosts of
dodders. Landw. Vers. Stat. 61:313-317. Abs. in Ex. Sta.
Ree. 16 :884.

Olive, E. W. The killing of mustard and other noxious weeds in
grain fields by the use of iron sulphate. Bull. S. D. Agr. Exp.
Sta. 112 :485-498.

Pammel, L. H. The Canada thistle and dandelion. Bull. Ia.
Agr. Exp. Sta. 61:148-153.

Exterminating quack grass. Pr. Bull. Ia. Agr. Exp. Sta.
11 :4.

The methods of exterminating milkweed, horse nettle, drop-
seed grass, cocklebur, foxtail, squirreltail, mustard, butter-
print and morning glory. Pr. Bull. Ia. Agr. Exp. Sta. 13-4.

Squirreltail grass or wild barley. Bull. Ia. Agr. Exp. Sta.
30 :302-321.

HISTORY AND BIBLIOGRAPHY 851

Pammel, L. H., and King, C. M. A few troublesome weeds. Pr.
Bull. Ia. Agr. Exp. Sta. 23:4.

Notes on eradication of weeds with experiments made in
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Unlawful Iowa weeds and their extermination. Cir. Ia.
Agr. Exp. Sta. 5:18.

Pereival, J. ‘‘Couch”’ or ‘‘Twitch.’’ .Jour. Bd. Agr. 16 :279-282.
Also see Bot. Centrbl. 114:480. (Agrostis vulgaris Trin.) 3.
‘““Onion Couch’’ (Arrhenatherum avenacewm, Beauv. v.
bulbosum Lindl.) Popular description. Discusses vegetative
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Weeds and their suppression. Jour. Bd. Agr. 10 :461-467.
1904. Abs. in Ex. Sta. Rec. 16:61.

Rawson, W. B., Dibble, W., Gillanders, F., Drysdale, J., and Earn-
shaw, G. T. On combating noxious weeds. See Ann. Rept.
N. Z. Dept. Agr. 17 :123-132 ; 350-358; 385-434; 442-447. Abs.
in Ex. Sta. Rec. 24:234.

Rhodin, S. On iron sulphate and lime nitrogen for weed eradica-
tion. K. Landtbr. Akad, Hardl, och Tidskr. 50: 433-445. 2 f.
1911. Abs. in Exp. Sta. Rec. 26 :839.

Roussille. The destruction of wild mustard. Bul. Soc. Nat. Agr.
France 64:451-452. Abs. in Ex. Sta. Rec. 16:476.

Rumler-Breslau, Dr: Unkrautvertilgung. 9 Heft der ‘‘Tages-
fragen aus dem modernen Ackerbau.”’

Sandor, C. On eradication of charlock and wild mustard. Kiesérlet
Kozlem 14:720-727. 1911. Note in Exp. Sta. Rec. 27 :536.
Selby, A. D. Noxious weeds along thoroughfares and their destruc-

tion. Bull. Ohio Agr. Exp. Sta. 59:5.
Spraying to kill weeds. Some useful methods. Cir. Ohio
Agr. Exp. Sta. 102:6.

Seton, R. S: Destruction of charlock by spraying. Yorkshire Col.,
Leeds and Yorkshire Council Agr. Ed. 1908: 3. (H. S. R.
16 :883.)

Somerville, Prof. Eradication of charlock in corn crops by spray-
ing. Trans. Highland and Agricultural Soc. Scotland. 138:
10-17.

Shaw, T: Weeds and how to eradicate them. St. Paul. p. 2386.
oat:

Smith, P. H., Chapman, G. H., and Stone, G. E. Notes on seeds,
screenings, and weeds in Massachusetts. Rept. Mass. Agr. Exp.
Sta, 1908 Pt. 1

852 WEED FLORA OF IOWA

Spillman, W. J., and Cates, J. S. Agronomic habits of rootstock
producing weeds. Proc. Soc. Prom. Agr. Sci. 29 :57-66.
Stebler, F. G., & Schroter, C. Die wichtigen Unkrauter der Futter-
wiesen und ihre Bekémpfung. lLandwirtschaftliches Jhrb.

der. Schweiz. 5:141-216. 20 col. pl. 1891.

Stone, A. L. The control of quack grass and Canada thistle. Cir.
Inf. Wis. Agr. Exp. Sta. 19:13.

Stone, G. E. The effects of chemicals and proprietary prepara-
tions on vegetation and weeds. Ann. Rept. Mass. Agr. Ixp.
Sta. 1908, Pt. 1:62-72. .

Tandberg, G. Report of the department of Agriculture of Nor-
way, 1909, contains article on eradication of weeds. <Aarsbher,
offentl. Foranst, Landbr. Fremme. 1909. I. Statsforanst.

Triboulet, Rommatin, and Saint-Quentin. On destruction of wild
mustard. Bull. Soc. Nat. Agr. France 64:461-466. Abs. in
Ex. Sta. Rec. 16:476.

Trubenbach, P. The combating of weeds. (Fihling’s Landw.
Ztg. 53:749-756; 798-805.) Abs. in Exp. Sta. Rec. 16:883.

Voeleker, J. A. Eradication of wild onion. See Woburn Field
Experiment. (Jour. Roy. Soc. Eng. 69:360-361; 72 :404-409.)

Weeds as affected by lime. ib. 350. Abs. in Ex. Sta. Rec.
23 532-533.

Experiments in weed prevention. Jour. Roy. Agr. Soc.
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Waldron, L. R. Weeds. Sp. Bull. N. D. Agr. Exp. Sta. 2:4.

Weed, C. M. Farm friends and farm foes, x1:334. 1910. Chicago.

Wilcox, E. M. Dodder v. alfalfa. Cir. Bur. Insect Pest and Plant
Dis. Neb. Agr. Exp. Sta. Dir. Bot. 3:3.

Wilcox, E. V. Carbon bisulphid for killing weeds. Pr. Bull.
Hawaii Agr. Exp. Sta. 25:4.

Killing weeds with arsenite of soda.. Pr. Bull. Hawaii Agr.
Exp. Sta. 30:15.

Poisonous weeds and their eradication. Cy. Am. Agr. 3:
119-122.

Williams, T. A. Fungi damaging both useful plants and weeds.
Bull. S. D¥Agr. Exp. Sta. 29 :51-52.

Willing, T. N. Noxious weed inspection. Rept. Dept. Agr. N. W.
Ty. 1901: 56-64.

Wilson, A. D. Some common weeds and their eradication. Bull.
Minn, Agr. Exp. Sta. 95:195-237.

HISTORY AND BIBLIOGRAPHY 853

Wilson, F. W. Johnson grass control. Rept. Ariz. Agr. Exp. Sta.
1911: 549-550. o8
Wittrock, V. B. Cuscuta ewropaea and its hosts. Svensk. Bot.

Tidskr. 3:1-17.
Woods, A. F. The wastes of the farm. Yrbk. U. 8S. Dept. Agr.
1908: 195-216 (Weeds 207.).

Woods, C. D., and Bartlett, J. M. On destroying wild mustard and
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Zinger, N. Ueber die im Lein als Unkraut auftretenden Camelina
und Spergula Arten und ihre Abstammung. Travaux Musée
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Centrbl. 119 :298-300.

MEDICINAL PLANTS.

Barton, W. C. Vegetable materta medica of the United States;
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Bigelow, Jacob. American medical botany. A collection of the
native medical plants of the United States. 3 v. 596 p.
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Blankenship, J. W. Native economic plants of Montana. Bull.
Mont. Agr. Exp. Sta. 56:36.

Chesnut, V. K. Plants used by the Indians of Mendocino Co.,
Cal. Cont. U. S. Nat. Herb. 7 :295-408.

Thirty poisonous plants of the United States. Far. Bull.
U.S. Dept. Agr. 86:32.

Duggar, J. F.. Melilotus. Cye. Amer. Agric. 2 :467-468.

Evans, J. R. Medicinal plants of the Cherokees. Proc. Am. Phar.
Assoc. (Abs.) 23 :289-336.

Gattinger, A. The medicinal plants of Tennessee. 128. Nash-
ville, 1894.

Gibbons, W. P. Medicinal plants of California. Proc. Am. Phar.
Assoc. 19 :297-308.

Greenish, H. G. An introduction to the study of Materia Medica,
being a short account of the more important crude drugs of
vegetable and animal origin. 571. London, 1899.

Hayne, F. G. Darstellung und beschreibung der Arzneigewachse
wie auch solcher pflanzen welche mit ihnen verwechselt werden
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Henkel, Alice. American medicinal leaves and herbs. Bull. U. S.
Dept. Agr. Bur. Pl. Ind. 219 :56.

American root drugs. Bull. U. S. Dept. Agr. Bur. Pl. Ind.
107 :80.

854 WEED FLORA OF IOWA

Weeds used in medicine. Far. Bull. U. 8S. Dept. Agr.
188 :45.

Wild medicinal plants of the United States. Bull. Bur.
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Henkel, Alice, & Klugh, G. F. The cultivation and handling of
golden seal. Cir. U. S. Dept. Agr. Bur. Pl. Ind. 6:19.

Golden seal. Bull. U. 8S. Dept. Agr. Bur. Pl. Ind. 51:35-46.

Holm, Theo. Medicinal plants of the U. S. (A series of articles
in Merck’s Report) 1910.

Hyams, C. W. Medicinal plants which have been collected and
used in North Carolina. Bull. N. C. Agr. Exp. Sta. 150:
329-409.

Johnson, L. A manual of the medical botany of North America.
292. New York, 1884.

Kellogg, Harriette S. Folk-lore in medicinal plants. Trans. Ia.
St. Hort. Soc. 39 :143-148.

Klugh, G. F. Tansy. Cy. Am. Agr. 2:465. (Cy. Amer. Hort.)

Kramer, H. A textbook of botany and pharmacognosy. Ed. 4.
888. Philadelphia, 1911.

Millspaugh, C. F.. American medical plants. An illustrated and
descriptive guide to the American plants used as homeopathic
remedies, their history, preparation, BEERS and physiolog-
ical effects. 2 v. 190. 180 pl.

Pammel, L. H. A manual of poisonous plants, chiefly of eastern
North America, with brief notes on economic and medicinal
plants, and numerous illustrations. 977, 17 pl, 458 f. Cedar
Rapids. 1911. (Many articles on medicinal plants are listed
in the bibliography.)

Poisonous and medical plants of Missouri. Bull. Mo. Bd.
of Hort. 14:46. .

Peterson, Maude G. How to know wild fruits. A guide to plants
when not in flower, by means of fruit and leaf. 340. 1905.

Porcher, F. P. Resources of the southern fields and forests,
medical, economical and agricultural, being also a medical
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Rafinesque, C. S. Medical flora: or manual of the medical botany
of the United States of North America. 2 v. 544. 48 pl.

Schoepf, J. D. Materia medica americana, potissimum regni
vegetabilis. 170. 1787.

Special Crops. Contains directions for cultivating such plants as
ginseng, ete. Edited by C. M. Goodspeed. Skaneateles, N. Y.

HISTORY AND BIBLIOGRAPHY 855

True, R. H. Cultivation of drug plants in the United States.
Yrbk. U. 8S. Dept. Agr. 19038: 337-346.
Medicinal, condimental and aromatic plants. Cy. Am. Agr.
2 :458-467.
Progress in drug plant cultivation. Yrbk. U. S. Dept. Agr.
1905: 532-540. (Domestication of wild drug plants, 534-535;
Utilization of weeds, 535-536.)
Weschke, C. The enumeration of the medicinal plants of Minne-
sota. Phar. Rund. 8:155-157.
Young, T. B. American Wormseed (Chenopodium anthelmint-
cum). Cy. Am. Agr. 2:466.

WEED SEEDS.

Ball, C. R. The purity and vitality of grass seed. Bull. Ia. Agr.
Exp. Sta. 54:164-180.
Ball, O. M. Alfalfa seed testing. Bull. Tex. Agr. Exp. Sta. 81:15.
Beach, C. L. The viability of weed seeds in feeding stuffs. Bull.
Vt. Agr. Exp. Sta. 138 :11-20.
Beal, W. J. Seeds of Michigan Weeds. Bull. Mich. Agr. Exp. Sta.
260 :101-182. .
Testing Seeds. Rept. Mich. Bd. Agr. 1877: 377-392.
Vitality and growth of seeds buried in the soil. Proc. Soe.
Prom. Agr. Sci. 10:15-16.
The vitality of seeds. Proc. Soc. Prom. Agr. Sci. 26 :89-93.
The vitality of seeds buried in the soil. Agr. Sci. 8 :284.
Proc. Soc. Prom. Agr. Sci. 6:14-15; 15:283. Rept. Mich. Bd.
Agr. 1884: 332-334.
The vitality of seeds twenty years in the soil. Proc. Soe.
Prom. Agr. Sci. 20 :86-87.
Bessey, E. A. Seed analysis for 1911 and 1912. Bull. Mich. Agr.
Exp. Sta. 270:71-98.
Boynton, M. F. Observations upon the dissemination of seed. Bot.
Gaz. 20 :502-508.
Brown, Edgar. Legal and customary weight per bushel of seeds.
Bull. U. S. Dept. Agr. 51 :27-34.
Brown, E., & Hillman, F. H. Seeds of red clover and its im-
purities. Far. Bull. U. S. Dept. Agr. 169 :24.
Burchard, O. Die Unkrautsamen der Klee-und Grassaaten mit
besonderer Beriicksichtigung ihrer Herkunft. 100, 5 pl. Ber-
lin, 1900.

856 WEED FLORA OF IOWA

On object and methods of seed investigation and establish-
ment of seed control stations. Exp. Sta. Ree. 4:793-801;
882-900.

Ueber die Herkunftsbestimmung amerikanischer Kleesaaten.
Mittheilungen aus dem Bot. Laboratorium mit Samen-Pri-
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Abs. in Beih. zum. Bot. Centbl. 4:397.

Butz, G. C. Germination experiments. Ann. Rept. Penn. St.
Coll. Exp. Sta. 1887: 20-21; 1889: 163-165. Bull. Penn. Agr.
Exp. Sta. 4:8-10.

_Carruthers, W. Dodder seeds in seed mixtures. Jour. Roy. Agr.
Soc. 69:311-313. Weeds in Clover seeds. id. 308-310.

Chapman, G. H. The microscopical examination of cattle foods.
Bull. Mass. Agr. Exp. Sta. 141:71. 52 f.

Cieslar, Untersuchungen iiber den Einfluss des Lichtes auf die Kei-
mung der Samen. Forschungen aus dem Gebiete der Agrikul-
turphysik. 1883. 6:270-295.

Crocker, Wm. Role of seed coats in delayed germination. Bot.
Gaz. 42 :265-291.

De Loach, Gertrude B., Carrier, L., & Hutcheson, T. B. Impurities
of grass and clover seeds sold in Virginia. Bull. Va. Agr.
Exp. Sta. 184:3-18.

Devol, W. S. Vitality tests of seeds. Rept. Ohio Agr. Exp. Sta.
1:113-116 ; 2:149-181; 3 :186-203; 4:136-185; 5:234-258; 6 :283-
285. :

Dewey, L. H. Dodders infesting clover and alfalfa. Cir. U. S.
Dept. Agr. Div. Bot. 14:7.

Dorph-Peterson, K. On some investigations of the appearance and
longevity of weed seeds. Tidskr. Landbr. Planteavl. 17:
584-626.

Duvel, J. W. T. The storage and germination of wild rice seed.
Bull. U. S. Dept. Agr. Bur. Pl. Ind. 90:34.

The vitality and germination of seeds. Bull. 58:96.

Vitality of buried seeds. Bull..83:20; 3 pl.

Ewart, A. J. On the longevity of seeds. Proc. Roy. Soe. Victoria.
n. ser. 1908. 1: Abs. in Exp. Sta. Rec. 20:628.

Fawcett, H. S. The viability of weed seeds under different condi-
tions of treatment, and a study of their dormant periods. Proc.
Ta. Acad. Sei. 15 :25-45.

Fruwirth, C. On color and specific gravity of clover seeds. Landw.
Vers. Stat. 55:439-452. Abs. in Exp. Sta. Rec. 13:656.

HISTORY AND BIBLIOGRAPHY 857

Garman, H. On the adulterants and weed seeds found in Ken-
tucky samples of blue grass, orchard grass, timothy, red clover,
mammoth clover and alfalfa seeds. Bull. Ky. Agr. Exp. Sta.
124 :35.

Garman, H., & Didlake, M. L. The inspection of seeds under the
Kentucky pure seed law. Bull. Ky. Agr. Sta. 127:129-169.

Harrington, G. T. The grass and clover seed trade in Vermont in
1907-1909. Bull. Vt. Agr. Exp. Sta. 146 :205-240.

Harvey, F. L. Examination of seeds for impurities. Rept. Me.
Agr. Exp. Sta. 1891: 186-187.

Germination experiments. Rept. Me. Agr. Exp. Sta.
1887: 149-160; 1888: 136-147; 1889: 150-160; 1890: 107-112.

Vitality of seeds. Note in Bot. Gaz. 12 :253.

Weeds and seeds. Rept. Me. Agr. Exp. Sta. 1896: 113-116.

Harz, C. D. Landwirthschaftliche Samenkunde. 1:552; f. 1-14.

' 2.:503-13862; f. 15-201. Berlin, 1885.
Hicks, G. H. Pure seed investigation. Rept. U. S. Dept. Agr.
1894: 389-408.

Hicks, G. H., & Key, Sothoron. Additional notes on seed testing.
Yrbk. U. S. Dept. Agr. 1897: 441-452.

Hillman, F. H. The adulteration of forage plant seeds. Far. Bull.
US. Dept. Aer. 332223.

Clover seeds and their impurities. Bull. Nev. Agr. Exp. Sta.
47 :88.

Vetch seed and its adulterants. Far. Bull. U. S. Dept. Agr.
515 :23-27.

Jenkins, E. H. Seed tests. Ann. Rept. Conn. Agr. Exp. Sta.
1879: 121; 1880: 96-104; 1882: 93; 1883: 96-107.

Jenkins, E. H., Card, F. W., Lazenby, W. R., Brown, E., & Shamel,
A.B. Rules and’apparatus for seed testing. Adopted by the
standing committee on methods of seed testing of the Associa-
tion of American Agricultural Colleges and Experiment Sta-
tions. Cir. U. S. Dept. Agr. Offi. Exp. Sta. 34:24.

Jenkins, E. H., & Warneke. Seed tests. Ann. Rept. Conn. Bd.
Agr. 1878: 352.

Johnson, T., & Hensman, R. Agricultural seeds and their weed
impurities, a source of Ireland’s alien flora. Sci. Proc. Roy.
Dub. Soe. n. s. 12:446-462. 1910. Abs. in Exp. Sta. Rec.
24 :338.

Jones, L. R., & Orton, W. A. Impurities of Vermont clover seed.
Rept. Vt. Agr. Exp. Sta. 11:229-234,

858 WEED FLORA OF IOWA

Kienitz, M. Ueber Ausfiihrung von Keimproben. Forst. Fl. 6.
Abs. in Bot. Cent. 1:52-53. 1880.

Kinzel, W. Concerning the germination of dodder seed. Naturw.
Ztschr. Han.- u. Forstw. 1903: 104-110.

On the germination of half-ripe dodder seed. Landw. Vers.

Stat. 55:255-256. Abs. in Exp. Sta. Rec. 13 :658.

Kolkwitz, R. Ueber die Athmung ruhenden Samen. Ber. Deutsch.
Bot. Gesells. 19 :285-287. 1901.

Korsmo, E. On the viability of weed seeds after passing through
the digestive tract of farm animals. Tidskr. Norske. handbr.
18 :223-230.

Kuntze, R. E. Germination and vitality of seeds. Torrey Bot.

_ Clubs 2190a.
Lehmann, Ernst. Ueber die Beeinflussung der Keimung lichtemp-

findlicher Samen durch die Temperatur. Zeits. f. Bot. 4:465-
529.

Laschke, W. Hinige vergleichende Untersuchungen iiber den Ein-
fluss des Keimbettes, sowie des Lichtes auf die Keimung ver-
schiedener Saémereien. Landw. Vers. 65 :295.

McCarthy, Gerald. Seed-testing; its uses and methods. Bull.
N. C. Agr. Exp. Sta. 108 :349-415.

Munerati, O., & Zapparoli, T. V. On investigations on the ger-
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Nobbe, F.. Handbuch der Samenkunde. 631: Berlin. 1876. On
viability of seeds, see Landw. Vers. Stat. 13 :233.

Pammel, L. H., Buchanan, R. E., & King, C. M. The vitality,
adulteration and impurities of clover, alfalfa, and timothy
seed in Iowa in 1906. Bull. Ia. Agr. Exp. Sta. 88:69.

Pammel, L. H., and King, C. M. Delayed germination. Proce. Ia.
Acad. Sei. 18 :20-33.

Results of seed investigations for 1907. Bull. Ia. Agr. Exp.
Sta. 99 :71-91.

Results of seed investigation for 1908 and 1909. Bull. Ia.
Agr. Exp. Sta. 115 :156-177.

Pammel, L. H., & Lummis, G. M. The germination of weed seeds.
Proce. Soc. Prom. Agr. Sci. 1908: 89-92.

Panton, J. H. Impurities in clover seed. Bull. Ontario Agr. Coll.
98:3: 20%,

Weeds of Ontario. Rept. Ont. Agr. Coll. & Exp. Farm.
19 :27-32.

HISTORY AND BIBLIOGRAPHY ee)

Parsons, C. L. A summary of American seed tests. Agr. Sci.
7 :541-545.

Pieters, A. J. The farmer’s interest in good seed. Far. Bull. U.S.
Dept. Agr. 111 :24.

Red Clover seed. Cir. U. 8. Dept. Agr. Div. Bot. 24:5.

Seed of red clover and its impurities. Far. Bull. U. S. Dept.
Agr. 260 :24.

Testing seeds at home. Rept. U. S. Dept. Agr. 1895:
175-184.

‘Pieters, A. J.. & Brown, E. Kentucky blue grass seed; harvest-
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Ihave ale)eney

Ridley, H. N: Dispersal of seeds by birds. Nat. Sci. 8:186-199.

Roberts, H. F., & Freeman, G. F. Alfalfa seed; its adulterants,
substitutes and impurities, and their detection. Bull. Kan.
Agr. Exp. Sta. 133 :53-111; 33 pl.

Rolfs, P. H. Preliminary report on the examination of some seeds.
Bull. Ia. Agr. Exp. Sta. 13 :75-84.

Samek, J. On vitality of seeds. See Tirol. Landw. Blatter. 18.
1894: 161-162. Abs. in Exp. Sta. Rec. 6 :429-430.

Settegast. Die landwirthschaftlichen Samereien und der Samen-
bau. Leipsic, 1892.

Selby, A. D., & Hicks, J. F. Clover and alfalfa seeds. Their
purity, palit: and manner of testing. Bull. Ohio baer Exp.
Sta. 142 :111-130; 4 pl.

Smith, P. H., Chapman G. H., and Stone, G. E. Notes on seeds,
screenings, and weeds in Massachusetts. Rept. Mass. Agr.
Expeista, (1908. Pt. 1.

Stewart, F. C. Impurities of clover seed. Bull. Ia. Agr. Exp. Sta.
21 :805-815.

Stewart, F. C., & French, G. T. Dodder in alfalfa seed. Cir. N. Y.
Agr. Exp. Sta. 8:4 (n. s.).

Stewart, F. C., French, G. T., & Wilson. Troubles of alfalfa in
New York. Bull. N. Y. Agr. Exp. Sta. 305 :333-416.

Thornhber, J. J. Practical suggestions for seed testing. Bull. Ariz.
Agr. Exp. Sta. 54 :99-102.

Vandevelde. Die Keimung der zaadplanten Morphologie en
Physiologie. Gent. 1896.

Waldron, L. R. Buried weed seeds. Bull. N. D. Agr. Exp. Sta.
62 :439-446.

Wollny, E. Saat u. Pflege. der lena sarihechafthichen Kultur-
pflanzen. Berlin, 1885.

860 WEED FLORA OF IOWA

Woods, Chas. D. Testing seeds. Bull. Me. Agr. Exp. Sta. 36:8.

WEED LAWS.

Bolley, H. L. The seed control act. Special Seed Bull. N. D. Agr.
Exp. Sta. 1:15.

Burtt-Davy, J. B. Text of law in regard to burweed (Xanthium
spinosum). See Far. Bull. Transvaal Dept. Agr. 54.

Clark, G. H. Weed control and weed legislation. Cy. Am. Agr.
4 :533-536.

Dewey, L. H. Legislation against weeds. Bull. U. S. Dept. Agr.
Div. Bot. 17:60.

Garman, H. and Didlake, M. L. The inspection of seeds under the
‘Kentucky Pure Seed Law. Bull. Ky. Agr. Exp. Sta. 127:
129-169.

Laws of Iowa relating to Agriculture. Jowa Yearbook Agr.
9 :944-958.

Maine law in regard to seeds. An act to regulate the sale of Agri-
cultural Seeds. Rept. Me. Agr. Exp. Sta. 1896: 143-181.
Taylor, F. W. Results of seed tests for 1911. (Includes text of

seed law.) Bull. N. H. Agr. Exp. Sta. 156 :14.

Thistles, illustrated description of, ete., included within the pro.
visions of the Thistle Act of 1890. Victoria Dept. Agr.

Tillman, O. I. Purity and germination of agricultural and vege-
table seeds sold in North Carolina. (Contains seed law.)
Bull. N. C. Agr. Exp. Sta. 32:78; pls. 8. f. 2.

GENERAL.

Anderson, L. Weedy flavors in butter. Ann. Rep. Cal. Agr. Exp.
Sta. 1902-8: 121-126. Exp. Sta. Ree. 15:813.
Bailey, L. H. Some reflections upon weeds. Bull. Cor. Agr. Exp.
Sta. 62 :522-526.
Bowen-Jones, J. Influence of weeds on crops. Jour. Roy. Agr.
Soc. Eng. 66 :122.
Brenchley, W. E. The weeds of arable land in relation to the soil
on which they grow. Ann. Bot. 25:155-165; 26 :95-109.
Weeds in relation to soils. Jour. Bd. Agr. (London)
18 18-24. 1911.
Weeds; their peculiarities and distribution. Sci. Prog.
Twentieth Cent. 1912: 413-437.
Carruthers, W. Determination of weeds. Jour. Roy. Agr. Soe.
Eng. 3:738-742. Jour. Roy. Agr. Soe. 69 :313-315.

HISTORY AND BIBLIOGRAPHY 861

Cates, J. S., & Cox, H. R. The weed factor in the cultivation of
corn. Bull. U. S. Dept. Agr. Bur. Pl. Ind. 257 :35.

Dewey, L. H. ‘‘Caesar Weed’’ useful as a fiber plant. See Cye.
of Amer. Agri. 2 :285.

Weeds in cities and towns. Yrbk. U. 8. Dept. Agr. 1898:
193-200.

Henfrey, Arthur. Outlines of the natural history of Europe. The
vegetation of Europe, its conditions and causes. 387. 4 col. tab.
1852.

Halsted, B. D. Our worst weeds, a scale of points. Proce. Soe.
Prom. Agr. Sci. 10:39-43.

Holtz, F. L.| Weeds. Nat. Study Rev. 6:237-245. 1910.

Pammel, L. H. A talk on weeds. (Address delivered before
County Road School, Clinton County, Iowa, 1910—with ap-
pendix describing a few weeds.) 54. Ames, 1910. |

Weeds of the Farm and Garden. 281, 161 f. Orange Judd
& Co., 1911.

Pammel, L. H., & Fogel, E. D. The underground organs of a few
weeds. Proc. Ja. Acad. Sci. 16 :31-40.

Severance, G. Germination of wheat affected by Russian Thistle
in the soil. See Pop. Bull. Wash. Agr. Exp. Sta. 15. Abs. in
Exp. Sta. Rec. 21:130.

Shull, C. A. The oxygen minimum and the germination of Xan-
thium seeds. Bot. Gaz. 52 :453-477.

Stone, A. L. The weed situation. Rept. State Conserv. Com. Wis.
1911: 60-67.

Teindl, J. C. Die Unkrautpflanzen. Vienna, 1827.

Toumey, J. W. Something about weeds. Bull. Ariz. Agr. Exp.
Sta. 22:32.

Tronmer. Bonitirung des Bodens. 1853.

Vitek, E. Weed studies.. Monatsch. Landw. 3:333-344. 1910.
Abs. in Exp. Sta. Ree. 24:543.

Waldron, L. R. Weed Studies. Bull. N. D. Agr. Exp. Sta.
62 :449-457.

Weaver, A. T. Farm management and weeds. Farm Weeds.

1909 (Nov.): 1.

Williams, T. L. Some plants injurious to stock. Bull. S. D. Agr.
Exp. Sta. 33 :21-44.

Wilson, A. D. Cost of weeds to the farmer. See Farm Weeds.

862 WEED FLORA OF IOWA

GLOSSARY.
BY HARRIETTE S. KELLOGG.

Accumbent. lying against, as when the edges of the cotyledon
lie against the caulicle or radicle.

Achene. A dry, hard, 1-celled, 1-seeded, indehiscent fruit.

Acuminate. Tapering somewhat gradually to a point.

Acute. Ending in a sharp angle, not prolonged.

Aerial roots. Those appearing on the stem above ground; may
_be brace roots as in corn, or clinging roots as in ivy.

Albumen. Nutritive material in seeds accompanying the
embryo.

Aleurone grains. Protein grains replacing albumen in a few oily
seeds, and starch in others.

Aleurone layer. Outer layer of the endosperm next to the peri-
sperm.

Alternate (leaves). One at a node, not opposite; (flowers) parts
of one whorl opposite to intervals of next.

Anatropous. Inverted and straight.

Angiosperms. Higher seed plants.

Angium. Case for pollen grains.

Annual, A plant that performs its life cycle from germination
to matured seed in one season.

Annual (Winter). A plant that germinates in the fall, grows
until frost; but blooms and matures seed the following spring.

Anther. The part of the stamen which contains the pollen.

Apetalous. Without petals.

Apex. Is opposite to point of attachment.

Appressed. Lying flat against.

Arachnoid. Cobwebby; covered with tangled hairs, fewer and
longer than when tomentose.

Arrow-shaped. See Sagittate.

Ascending. Rising obliquely or curving upward.

Auricle. An ear-shaped appendage.

Awn. An appendage composed of bristles.

Axil. The upper angle formed between the leaf and stem.

Axis. The central line of any organ or support of a group of
organs.

Axillary. In the axil.

Barbed. With ridged points or short awns usually reflexed.

HISTORY AND BIBLIOGRAPHY 863

Base. The part of an organ nearest its point of support.

Beard. Awns of grasses; a tuft of hairs, generally stiff and
long.

Biennial. Of two years duration; a plant germinating one
season and maturing seed the next.

Bract. A modified leaf subtending a flower or flower branch.

Bracteate. Furnished with bracts.

Bristle. A short stiff hair.

Bulb. A leaf bud with fleshy scales; usually subterranean.

Bulbiferous. Bulb-bearing.

Callus. A hard protuberance or ecallosity.

Calyx. The outer part of the perianth.

Caneseent. Hoary with gray or white pubescence.

Capillary. Hair-like.

Capitate. With a globose head. Collected in a head or dense
cluster. .

Capsule. Any dry dehiscent fruit composed of more than one
carpel. é

Carpel. A simple pistil or one element of a compound pistil.

Caryopsis. A dry one-seeded indehiscent fruit with a thin, ad-
herent pericarp as in many of the grasses.

Caulicle. The first internode of the stem above the true root.

Cauline. On the stem.

Cellulose. Primary cell wall substance. A carbohydrate having
the general formula (C,H,,0,) n.

Chaff. A small thin seale or bract becoming dry or membranous
as in the glume of grasses or bracts on head of composite.

Chalaza. That part of the ovule where all the parts grow to-
gether. ‘

Chlorophyll. Green coloring matter of plants.

Chromataphore. The color-granule.

Ciliate. ° Having hairs or bristles on margin.

Circumscissile. Dividing by a transverse circular line as in
capsule of purslane.

Clavate. Club-shaped; gradually thickened away from the point
of attachment. ;

Cleft. Having narrow sinuses extending about half-way to
base; as cleft leaf.

Cleistogamous. Fertilized in bud; closed flowers.

Climbing. Rising by laying hold of other objects without
twining. .

864 WEED FLORA OF IOWA ‘

Coma. A tuft of any sort.

Compound. Composed of two or more similar, subordinate
parts united into one whole.

Conduplicate. Folded upon itself lengthwise.

Cordate. Heart-shaped with point upward.

Coriaceous. Leathery.

Corolla. Inner part of the perianth.

Corymb. <A convex, or flat-topped, indefinite inflorescence, lke
a raceme with lower pedicels elongated.

Cosmopolitan. Widely distributed.

Cotyledons. The first leaves of a plant as found in the embryo.

Creeping. Running along above ground or beneath the surface,
and rooting.

Cremocarp. Fruit of Umbellifere.

Crenate. Dentate with rounded teeth.

Crested. Having a ridge or terminal appendage.

Crystalloids. Protein bodies in the form of crystals.

Culm. The stem of grasses.

Cuneate. Wedge-shaped.

Cut. Having divisions deeper than when dentate.

Cyme. <A somewhat flat-topped, determinate inflorescence, re-
sembling a corymb.

Decumbent. Reclining but with end rising.

Dehiscent. Opening in a regular manner by valves or slits to
discharge seeds.

Dentate. Toothed, usually with teeth directed outward.

Denticulate. Finely dentate.

Determinate Inflorescence. Flowers arise from terminal bud
and check growth of axis. :

Diadelphous (stamens). Collected in two sets.

Dicotyledonous. Plants producing two cotyledons.

Diffuse. Spreading loosely and irregularly.

Digitate. Compound with parts radiating from apex of support.

Dioecious. Having stamens and pistils in separate flowers upon
different plants. |

Divided. Having incisions extending to base or midrib.

Dorsal. Pertaining to back or outer surface of organ.

Downy. Having a dense covering of short weak hairs.

Elliptical. Oblong and rounded at ends.

Emarginate. Notched at end.

Embryo. Rudimentary plantlet within the seed.

HISTORY AND BIBLIOGRAPHY 865

Endosperm. Albumen of seed in embryo-sac as distinguished
from perisperm.

Epicarp. Outer layer of pericarp.

Epiderm. External layer of cells in any organ.

Epigynous. Corolla seems to rise from top of ovary.

Erect. Perpendicular, or nearly so, to the surface to which at-
tachment is made.

Exserted. Protruding beyond margin of Ee lvie as stamens
from corolla.

Faleate. Scythe-shaped.

Fertile. Capable of producing fruit.

Fibrovascular Bundle. A bundle of stringlike, woody, fibro-
vascular tissue, containing xylem and phloem.

Fibrous. Composed of fibers.

Filiform. Thread-shaped.

Floccose. Covered with mats or flocks of soft woolly hairs.

Foliate. Leaved, as trifoliate {three-leaved).

Fruit. The mature ovary and its contents with any closely ad-
hering part.

Funicle. The stalk of a seed or ovule.

Fusiform. Enlarged in the middle and tapering fanaa each
end.

Gamopetalous. Having petals more or less united.

Glabrous. Smooth.

Gland. A secreting surface or structure.

Glandular. Bearing glands or glandlike.

Glaucous. Covered with a whitish bloom, as on cabbage.

Globoids. Granules of calcium-magnesium-phosphate found in
grains of aleurone.

Globose. Spherical or nearly so.

Glomerate. Compactly clustered in a head.

Glume. One of the outer floral envelopes of grasses.

Glutinous. Viscid, sticky.

Hairy. Covered with hairs longer and coarser than’ when
pubescent.

Halberd-shaped. See hastate.

Hastate. Describing leaves which have spreading lobes at the
base.

Heart-shaped. See cordate.

Herb. A plant which contains but little wood in the stem and
which dies down to the ground each year.

dO

866 WEED FLORA OF IOWA

Herbaceous. Having the characters of an herb.

Hermaphrodite. Perfect, having both stamens and pistils in the
same flower.

Hilum. The scar of the seed; its place of attachment.

Hirsute. Clothed with rather coarse or stiff hairs.

Hispid. Beset with erect stiff hairs or with bristles.

Hypoderm. Beneath the epiderm.

Hypogynous. With parts under pistil.

Imbricated. Overlapping either vertically or spirally like
shingles of a roof. In aestivation, one piece is wholly external and
one wholly internal.

Imperfect. Applied to a flower lacking either stamens or pistils.

Included. Opposed to exserted; not protruding from the en-
velope.

Incumbent. Applied to cotyledons when the radicle is folded
back against one of them.

Indehiscent. Not opening by valves or slits.

Indeterminate Inflorescence. Flowers arise laterally and suc-
cessively as floral axis elongates.

Indurated. Hardened.

Inflexed. Bent abruptly inward or downward.

Inflorescence. The flowering part of a plant.

Inserted. Attached to or growing out of.

Integuments. Coats of ovule.

Internode. Any part of a stem situated between two nodes.

Interrupted. Applied to surface or series the continuity of
which is broken.

Involucre. A circle or collection of bracts immediately subtend-
ing a flower or inflorescence.

Tsodiametric. Equal in three dimensions.

Joint. A node.

Keel. A ridge somewhat resembling the keel of a boat; applied
especially to the two anterior united petals of a papilionaceous
flower.

Lamella. A thin plate.

Lamina. Blade or expanded part of leaf.

Lanceolate. Lance-shaped; tapering pep toward the base
and gradually toward the apex.

Lenticular. lLentil-shaped; in the shape of a double convex lens.

Ligneous, lignose, lignified. Woody in texture.

Ligulate. Refers to the strap-shaped corolla of composite flow-
ers, as Dandelions.

HISTORY AND BIBLIOGRAPHY 867

Ligule. A. A strap-shaped corolla, as in the ray flowers of
composites, like the sunflower. B. A membranous projection on
inner side of leaf at top of sheath of some grasses.

Linear. Long and narrow with nearly parallel margins.

Lobe. A rounded portion or segment of any organ.

Locule. Cavity within ovule.

Lumen. Internal space or cavity of a cell.

Lyrate. lLyre-shaped.

Membranaceous or membranous. Thin, soft, and generally trans-
lucent.

Malpighian Cells. Palisade cells in which one or more light lines
are present.

Mesocarp. Middle layer of pericarp.

Mesophyll. All of the fundamental tissue within the epidermis.
Micropyle. Opening through which pollen tube passes.
Monadelphous. Stamens united in one set.

Monocotyledon. One cotyledon.

Monoecious. With stamens and pistils in separate flowers on
the same plant.

Mother Cells. Large dense cells in pollen lobes.

Muecronate. Tipped with a short stiff point.

Multiple. Compound.

Murieate. Beset with short and hard or prickly points.

Nerve. Any vein on the floral envelopes of grasses.

Node. The place on a stem where one or more leaves are at-
tached; the joint.

Nueellus. Nucleus of an ovule.

Oblanceolate. Lanceolate with the broadest part toward the
apex.

Oblong. Widely linear.

Obovate. Inverted ovate.

Obtuse. Blunt or rounded at the apex.

Orbicular. Circular.

Osteosclerids. Cells generally accompanying Malpighian Cells
in Leguminose. They vary in shape and length, sometimes marked
by longitudinal canals.

Ovary. Seed case of pistil.

Ovate. Outline like that of an egg, with larger part downward.

Ovule. Unripe seeds in ovary.

‘Palet. Upper bract of the flower in grasses.

Palisade cells. Elongated cells perpendicular to epidermis on
upper side of leaf.

868 WEED FLORA OF IOWA

Palmate. Radiately lobed or divided.

Panicle. Loosely, irregularly branched raceme.

Papilionaceous. Butterfly-shaped, like the corolla of the pea, ete.

Papilla. A soft elongated projection.

Papillate. Having papillae.

Pappillose. Papillate.

Pappus. The modified limb of the calyx in corn, in Composite,
especially, when the summit is developed in a feathery or plumose
manner.

Parenchyma. All tissue composed of cells not having tapering
extremities; soft cellular tissue like that of pith.

- Parted. Cleft nearly or quite to the base.

Pedicel. A branch of inflorescence supporting one or more
flowers.

Peduncle. <A flower-stalk.

Perennial. Living more than two years.

Perfect. Having both pistil and stamens.

Perianth. The floral envelope including calyx and éorolla (or
calyx alone when corolla is absent) whatever their form.

Pericarp. The matured ovary.

Perigynia. The bodies around the pistil.

Perigynous. Parts around pistil.

Persistent. Remaining longer than usual, as calyx upon fruit,
or leaves which die but remain on trees through the winter.

Perisperm. The albumen of a seed.

Petal. A division of the corolla.

Petiole. The stalk of a leaf.

Phloem. Portion of fibrovascular bundle containing the bast
and sieve tissues.

Photosynthesis. Process by which sugar and starch are pro-
duced in a plant by means of the chlorophyll grain.

Pilose. Covered with long soft hairs.

Pinnate leaf. Compound with leaflets arranged on each side of
a common petiole.

Pinnatifid. Pinnately cleft.

Pistil. The central seed-bearing organ of the flower consisting
of ovary, style and stigma.

Pistillate. Provided with pistils; properly, without stamens.

Placenta. The part of the ovary to which the ovules are attached.

Plumose. Like a feather, having fine hairs on each side, as in
the pappus-bristles of thistles.

Pod. Any dry, dehiscent fruit.

HISTORY AND BIBLIOGRAPHY 869

Pollen. The fertilizing powder produced in the anthers.

Pollination. Transferring pollen from anther to stigma.

Polygamous. Plants bearing both perfect flowers and flowers
of either sex, or of both, as in the soft maple.

Pore-canal. Passage through a pit between adjoining cells.

Prickles. Short, stiff, spinelike growths from the epidermis, as
in the rose. .

Procambium. Fibrovascular tissue of an organ formed before
it is differentiated into xylem and phloem.

Prostrate. ying flat on the ground.

Protein. A plant food manufactured in the plant from starch or
sugar by the addition of one of the compounds of nitrogen, phos-
phorus, potassium or other similar substances.

Protogynous or proterogynous. Having pistils ready for fertili-
zation before anthers are matured.

Puberulent. Muinutely pubescent.

Pubescent. Covered with fine, soft; short hairs.

Raceme. A simple indeterminate inflorescence of pediceled flow-
ers arranged along a rather long, common axis.

Rachilla. Axis of spikelet in grasses.

Rachis. The axis of a spike or other body.

Radical. Proceeding from the root or base of stem.

Raphe. The continuation of the seed-stalk along the side of an
anatropous ovule or seed.

Receptacle. Summit of flower-stalk.

Reflexed. Abruptly bent or turned downward.

Repand. Having a slightly undulating margin.

Respiration. Process of absorption of oxygen and giving out of
carbon dioxide.

Reticulated. Net-veined.

Retrose. Directed backward or downward.

Rhizome. Any subterranean stem, usually rooting at the nodes
and rising at the apex.

Rib. A primary or prominent vein in a leaf.

Root. The descending axis of the plant, which supplies it with
nourishment.

Root-stock. See Rhizome.

Runeinate. Sharply toothed, the teeth directed backward.

Runner. A slender stolon that roots and forms new plants at
intervals.

Sagittate (leaves). Arrow-shaped, lobes with acute lobes and
apex.

870 WEED FLORA OF IOWA

Seabrous. Having a rough surface.

Seale. Any thin appendage, morphologically a modified, degen-
erated leaf.

Scape. A peduncle rising from the root, without proper foliage.

Secapose. Resembling a scape.

Searious. Dry and membranous.

Sclerenchyma. Lignified tissue as applied to thick-walled fibers.
- Selerotic. Consisting of sclerenchyma.

Seed. The ripened ovuie, enclosing a rudimentary plant, and
the food necessary for its germination.

Sepal. A division of the calyx.

Serrate. Having sharp teeth pointing forward.

Serrulate. Finely serrate.

Sessile. - Without a stalk; thus a leaf is sessile when the blade is
seated directly upon the See

Sheath. ‘A tubular envelope as the sheath of grasses.

Shrub. A woody perennial smaller than a tree and usually hay-
ing several stems.

Simple. Without subdivisions, opposed to compound; leaves, as
oak, dock, ete.

Sinuate. Having strongly wavy margin.

Sinuous. Wavy, curving back and forth.

Sinus. The cleft between two lobes or divisions.

Spatulate. Shaped like a druggist’s spatula, rounded at the
summit and gradually narrowed downward.

Spicate. Arranged in a spike.

Spike. An inflorescence like a raceme, except that the flowers are
sessile.

Spikelet. The characteristic inflorescence of grasses.

Spindle-shaped. See Fusiform.

Spine. A sharp, rigid process growing from the stem.

Sporangium. Spore ease.

Spore. Pollen grain; reproductive body of flowerless plants.

Spreading. Applied to branches that bend outward at less than
aright angle.

Stamen. A pollen-bearing organ of a flower.

Staminate. Applied to a flower or plant which has stamens, but
no pistils.

Stellate. Star-shaped.

Sterile. Unfruitful, as a flower without a pistil or antherless
stamen.

HISTORY AND BIBLIOGRAPHY 871

Stigma. That part of the pistil which receives the pollen.

Stipules. lLeaf-like appendages arranged in a pair at the base
of the leaf stalk.

Stolon, or stole. A trailing or reclining and rooting shoot.

Stoma. Opening into the epidermis by which air enters and
moisture escapes.

Striate. Marked with parallel lines or ridges.

Style. The slender part of a pistil supporting the stigma.

Sub-. <A prefix meaning somewhat or slightly.

Succulent. Juicy, fleshy.

Suspensor. Filament of cells in ovary.

Tapetal Cells. Cells surrounding mother cells in pollen and con-
taining food material.

Terete. Long and round.

Terminal. Attached to or pertaining to the extremity or apex,
as the terminal bud.

Testa. Outer seed coat. Sometimes both coats are spoken of as
the testa.

Tomentose. Densely pubescent with matted wool.

Tomentum. Matted, woolly hairs.

Toothed. See Dentate.

Trailing. Prostrate on the ground but not rooting.

Transpiration. Process by which leaves lose moisture,

Trichome. A plant hair of any kind.

Truncate. Ending abruptly as if cut off transversely,

Tuber. A short thickened subterranean branch.

Turbinate. Top-shaped.

Turgid. Thickened like a tuber, or distended with a liquid (never
with air).

Umbel. Any indeterminate inflorescence in which the peduncles
or pedicels of a cluster seem to rise from the same point.

Umbellate. Like an umbel.

Undulate. Having a wavy surface.

Urticating. Stinging. A term applied especially to the plant
hairs of members of the Urticaceae, some of which are poisonous.

Utricle. A small inflated membranous 1-seeded fruit.

Valve. 1. One of the parts of a dehiscent fruit. 2. Applied
also to the top of a pitcher in the Sarracenia. 7

Vein. A bundle of threads of fibro-vascular tissue in a leaf or
other organ. i

Verticillate. Whorled.

Villous. Bearing long, soft, straight hairs.

872 WEED FLORA OF IOWA

Viscid. Sticky, glutinous.

Wavy. Margin forms wavy line bending inward and Scere
in succession.

Wedge-shaped. See Cuneate.

Whorl. An arrangement of organs in a circle around a stem.

Wing. 1. Any thin or membranous expansion attached to or
bordering an organ. 2. The lateral petal of a papilionaceous
flower.

Winter annual. ‘See Annual.

Xylem. Woody part of fibrovascular bundle containing larger
continuous air-containing vessels; the water-conducting tissue.

INDEX

ABBREVIATIONS.
f=figure.

m=map.

sp=species,
syn=synonym.

Abbey, W. L. 766
Absinth 307
Abutilon theophrasti (syn. avicennae)
215-218) 718, 790, 796, 799, f. 216,
Dili, ak}
Distribution 734, 762,
Seed 557-558, f. 559
Acacia, False
Distribution 718
Acaena ovina 849
Acalypha virginica 205-207, 788, f. 206
Distribution 718, m. 207
Seed 457, f. 457
Acer saccharinum, Seed f. 634
Achene 862
Achillea millefolium 358-360, 778, 787,
f. 859, 741
Chemical composition 674
pispapation 698, 720, 736,

Seed 491, f. 491
Acidia heraclei 677
Acloque, A. 731, 737, 738, 740, 754, 837
Acnida tamariscina 118
tuberculata 118-119, 789, f. 118
Distribution m. 119
Seed 435, f. 435
tuberculata v. prostrata
Distribution, 716
Adams, G. BF. 846
Adaptation of plants 637
Aderhold, R. 846
Adulterated seed 811-815, 827, 856, 857,
858, 859, 860
Adulteration and Seeds Act 793
Adventive plants 696-697, 707
Aegopodium podagraria
Distribution 736
Aerial roots 862
Aethusa cynapium 663
Distribution 736
Africa, Weeds, 722, 731, 732,
African Colonies, South
Weed laws 793
Agastache scrophulariaefolia
Seed 567, f. 470, 567
geratum conyzoides
Distribution 734
Agoseris cuspidata 502, f. 501
Agrimonia striata
Distribution 734
Agropyron caninum
Distribution 715
repens 53-58, 664, 774, 796, 799, f. 54,
dé

mv. 216

740, m.

733, 734

Chemical composition 57-58
Distribution 715, 736, ™m. 55
Root system 652, f. 643
Seed 421-423, 810, f. 422, 688
smithii 53
Distribution m. 56
Seed 423, f. 423
tenerum
Distribution m. 56
Seed f. 4°2
Se ee ues Fithaee 125-126, 789, 819,
. 125, 70
qi uibation 699, 716, 735, 736, m.
2
Seed 436, 776, 810, 829, f. 436, 688

56

Allium canadense 67,

Agrostis alba 667
Distribution 715
Seed 415, 811, 8138, f. 405
canina 677
hyemalis
Distribution 732
sp. 664
spica-venti
Distribution 736
vulgaris 851
Agueweed 780
Aira caespitosa 667
AIZOACEAE
Distribution 723
Alabama Flora 707-708, 722-723
Alberta weed legislation 793
Albuge candida f. 681
Albumen 862
Alchemilla arvensis 664
Aleurone cells 524, 530, f. 523, 529
“fleck” 553
grains 862
layer 510, 519, ee ee,
Alfalfa 183, 852 as 595
Dodder
Seed 810
Rocket 159
Seed 810, 811, 812, 828. 831, 833, 855
Impurities 712, 833 834, 836, 839,
856, 857, 858, 859
Alfilaria
Distribution 725
Seed 457, f. 447
Alice, G. 847
Alien plants 697-698
Alkali soils, Weeds 820
Alkanet 256
GAS, WSl, io Os

Distribution 67, 68
carinata
Distribution 839
vineale
Distribution 715
Almond 175
Alopecurus agrestis 664, 665
Distribution 736
geniculatus f. 732
Distribution 715, 732-740
pratensis
Distribution 715
Alpers 713, 738, 740
Alsike Clover
Seed 450, 810, 812, 830, f.
Impurities f. 638
Alternate flowers 862
leaves 594, 862
Alyssum, Hoary 147-149, f. 148
Distribution 717, m. 148
Sweet 142
Amaranth
Family 113- 119
Distribution 723
Seed 434-435
Purple 697 :
Rough syn. Rough Pigweed
sp. f. 636
Spiny 697
Distribution 723
Spreading syn. Prostrate Pigweed
Tumbling syn. Tunbling Pigweed

f. 518

451, 638

Hote INDEX

AMARANTHACEAE 3, 113-119, 434-435
Bibliography 582
Distribution 716, 723
Amaranthus blitoides 117-118, 788, f.
117
Distribution 716, m. 117
Seed 434, f. 434
graecizans 115-116, 788, f. 116
Distribution 690, 716, 738
Seed 434, f. 434, 631
hybridus
Distribution 723
paniculatus 697
retroflexus 113-115, 790, f. 116
Chemical composition 115
Distribution 716, 723, 734,
m. 115
Seed 434, f. 435, 676
Trichomes, f. 115
sp. Distribution 705, f. 595
spinosus 697
z Distribution 723
viridis
Distribution 843
Ambrosia artemisiifolia 328-331, 778,
789, 849, f. 830, 331
Distribution 698, 704, 720, 730, 740,
Mm. 331
Seed 482-483, f. 483, 577
bidentata
Seed 483, f. 483
psilostachya 331-332
Distribution 689, f. 332
Root 651
Seed 484, f. 483
trifida 326-327, 691, 789, f. 327, 672
Distribution 691, 720, mm. 827
Seed 484, 574, f. 483
American
Germander 272-273, 469, 470, 789
Gromwell, 467
Weeds 698
Amsinckia
Distribution 725
intermedia
Distribution 844
ANACARDIACEAE 4, 213, 214, 215
Anagallis arvensis
Distribution 719, 740
Anaphalis margaritacea
Distribution 740
Anatropous seed 862
Anderson, J. P. XI, 751
Anderson, L. 860
Andropogon fureatus 688
scoparius 688, f. 689
sorghum technicus 512,
Seed 512-515
sp. Distribution 701
virginicum
Distribution 722
Anemia
Distribution 693
Anemone evlindrica
Seed 439, f. 439
Long-fruited
Seed 439, f. 439
ANGIOSPERMAE 38. 6-587
Angiosperms 6-587, 862
Angium 862
Angle-pod 787
Animals, Seed scattered by 629, f. 633,
635
Annual 647, 650, 691, 862
Brome grass syn. Soft Chess
Meadow Grass 664
Morning Glory 244, 245, 568, 564, 696
Sow Thistle 391-393
Sunflower 730. 756
Winter 647-648, 660, 691, 786, 862
Antennaria margaritacea
Distribution 705
plantaginifolia
Distribution 705

737,

f. 513, 514, 515

Anthemis arvensis
Distribution 735-736
cotula 360-362, 778, 788, f. 361
Distribution 696, 720, 736, m. 361
Seed 491, f. 491
Anther 615, 862, f. 615
Anthoxanthum odoratum
Distribution 693, 714
Apera spicaventi seed f. 639
Apetalous flowers 609, 862
Peppergrass syn. Large Peppergrass
Apex 862
Aphis
Bean 677 -
rumicis 677
Aplopappus sp. 846
APOCYNACEAE 4, 234-237, 701
Distribution 719, 723
Apoecynum androsaemifolium 235
Distribution 719, m. 285
androsaemifolium hypericifolium f.
236
cannabinum 235-237, 788, f. 236
Distribution 719, m. 237
Root 651
Apple 175, 632
Leaf, f. 591
May 618
-of-Peru
Distribution 737
Wild Balsam 573
Seed 574
Arable land, Weeds of 664, 665
Arbutus, Trailing 702
Arcangeli. G. 731, 737, 738, 740, 838
Arctium lappa 370, 371, 778, 789, 796,
(OS eer ls exra le ne)
Distribution 721, 725, m. 871
Root system 644
Seed 493, 576-577, f. 494, 577
sp. 577, 701
Argemone intermedia, 441, f. 440
Distribution 729
mexicana
Distribution 696
platyceras syn. A. intermedia

Argentine, Weeds 757
Aristida dichotoma 28-29, 790, f. 28
Distribution, m. 29
sp. Distribution 701
tuberculosa 29-30, f. 30
Arizona seed investigations 834
Arkansas weeds 757
Armstrong 768
Arnica cordifolia
Distribution 695
Arrhenatherum avenaceum
Seed 813
avenaceum v. bulbosum 851
Artemisia biennis 367-368, 790, f. 867
Distribution 705, 721, m. 368
Seed 492, f. 492
ludoviciana 3866-367, 790, f. 366
Distribution m. 367
Arthur, J. Ch T46e abd 75h 6 Gameton.s
826, 838
Artichoke 307, 346-348, 790, f. 346, 347
Distribution 691, 740, m. 347
Trichomes f. 488
Arum
Distribution 693
ASCLEPIADACEAE 4, 237-241, 634
Bibliography 582
Distribution 719
Seed 462-463, 562-563 ;
Asclepias cornuti syn. A. syriaca
inearnata 777
Seed 462, f. 463
speciosa 237-238, 787, f. 238
Distribution 719, m. 288
syriaca 239-241, 777. 788, f. 2389-240
Distribution 691, 705, 719, 79
240

INDEX 875

Root system 651, f. 646
Seed 462, 562-563, f. 463, 562, 632
tuberosa
Seed 463 f. 463
verticillata
Seed 463, f. 463
Ash 6, 632
Ashton, W. M. 766
Asia, Weeds of 731, 732, 7338, 734
Asparagus 6
Aspens 703
Aster azureus 689
drummondii 481
Trichomes f. 482
laevis 481, 689
Trichomes f. 482
macrophyllus 481
Trichomes f. 482
Many-flowered 317-318, 790, f. 317
Distribution 689, m7. 318
multiflorus 317-318, 790, f. 318
Distribution 690, m2. 318
Trichomes f. 481
novae-angliae, Trichomes f. 481
novi-belgii, Distribution 737
oblongifolius, Trichomes f. 481
panieculatus f. 320
parviflorus ‘
Distribution 737
salicifolius 319-320, 790, f. 320
Distribution 737, mm. 320
Seed 481, f. 481
Trichomes f. 481
sp. 594
tradescanti 320
Trichomes f. 781
White.. See Many-flowered
Willow-leaved 319-320, 790, f. 319
Distribution m. 320
Seed 481, f. 487
Astragalus canadensis 193, f. i194
mexicanus 554
Atriplex hortense
Distribution 736
patula v. hastata 109-110, f. 120
Distribution 716, 740, 789, m. 110
Seed 433, f. 433
Atropa belladonna
Distribution 736
Aughey 765
Auricle 862
Australia, Flora of 696, 731, 732, 73
734, 763
Seed investigations 837
Weed legislation 793
Weeds 839
Australian Burr 849
Avena fatua 40-41. 789, f. 40
Distribution 715. 736, mm. 41
Seed 415-416, 810, 829, f. 416
glabrata
Seed 829
sativa
Seed 813
Avens, Seed 449, 788, f. 449
White sin. Stickseed
Awn 609, 862, f. 609
Awned Brome grdss_ syn.
Brome Grass
Wheat grass 715
Awnless Brome Grass 812
Axil 862
Axillary flowers 610
Placenta f. 679
Axis, Floral, 611

Bakcock, O. G. 748
Bachelor's Rutton
Distribution 727
Bachmann, E. 586
Bailey, E. H. S. 837
Bailey, F. M. &28
Bailey, L. H. 847, 860

(St)

Downy

Baldwin’s Ironweed 309-310, f. 310
Distribution m. 310
Seed 477, f. 477

Ball, ©. R. 745, 760, 8384, 855
Ball, O. M. 834, 855
Ball Mustard 163, 717, 814
Balsam Apple 573, f. 574
Bamber, M. K. 847
Barbarea vulgaris 170, TMG on
Distribution 717, 733, 740, m. 171
Seed 447-448, 544, ff. 447, 542
Barber, C. J. 750
Barberry, 678
Family, Distribution 723
Barley 8
Blight f. 680
Blindness of 677
Grass 667
Little 61-63, f. 62
Chemical composition 61, 63
Distribution 715, m. 62
Seed f. 424
Seed 812 ‘
Transpiration 673
Wild syn. Squirrel-tail Grass

Barnaby’s Thistle syn. Knapweed

Barnet, 664

Barnyard Grass 16, 790, f. 16, 330
Chemical compositicn 17
Distribution 731, m. 16
Seed 411-412, 506, f. 412, 505, 729

Base 862

Bartlett, J. M. 853

Barton, L. W. 833

Barton, W. M. C. 773, 853

Basil 286
Distribution 720

Basswood seed 631, f. 632

Beach, C. L. 855

Beach, D. L. 834

Beal, eee XI, XIII, 24, 824, 830, 838,

Bean 67, 180, 624
Aphis 677
Castor-oil 205

Distribution 696
Coffee 180
Trailing wild

Distribution 718
Transpiration 673
Wild 199-200

Distribution 718, mm. 200

Seed 455, f. 455

Beard Grass 862

Distribution

Beard-tongue 845

Bebb, M. S. 747

Beck 765

Beck, G. 553. 585

Beck, L. C. 838

Bedford) S. -Ae ji

Bedstraw 572. 594. 663. 665, f. 573

Distribution 693, 741

Seed 4764, f. 476

Bee-plant, Rocky Mountain

f. W774, 175

Distribution 729, 739, m. 174

Seed 448, f. 448

Beet 99

Nistribution 712, 725

Root system 648
Sugar 99

Beetle, Colorado 677

Fly 676

Turniv Flea 676

Beggar’s Lice 259-260, 788, f. 259

Distribution 821

Seed 466, f. 467

Beggar-ticks 351-352, 624, 664, 789,

Oey re, Saul
Distribution 697. 720, 740, 1. 352
Root system 645

7

122

173-175,

876

Seed 489, f. 489, 633, 635
Black syn. Beggar-ticks
Small
Distribution 720
Sp. Seed f. 489
Bellis perennis 667
Bennett, J. L. 766
Bent Grass 667
Fine 664, 665
Reed, Distribution 736
Silky, Seed f. 639
Bentham, G. 731, 838
BERBERIDACEAE, Bibliography 582
Distribution 723
Bermuda Grass, Distribution 732
Bergen, J. W.
Bergen and Davis XII
Berlin Botanical Garden, weeds dis-
tributed by, 753
Bernholtz, L. 748
Berry 625
Bersch, W. 847
Berteroa incana 147-149, 788, f. 148
Distribution 700, 713, 717, m. 148
mutabilis
Distribution 700
Bessey, C. HB. 288, 584, 748, 755, 756,
758, 760, 761, 825, 847
Bessey, E. A. XII, 831, 855
Beta 532
vulgaris 725
Bettomer, Ellen 755
Bexar 767
Bibliography
Anatomical
580-587
Chemical composition of weeds 837
Distribution of weeds 837-846
Eradication of weeds 846-853
Medical plants 853-855.
Weed laws 860
Weed seeds 855-860
Bidens 624, 633, 789
aristosa 352-354, 489, 790, f. 353
Distribution m. 354
Trichome f. 490
bipinnata, Distribution 696, 734
Seed 489, f. lie 633
cernua 489,
Distribution 740
Trichome f. 490
discoidea 349-351, 789, f. 350
Distribution 691, 720, m. 350
Seed 489, f. 489, 577
frondosa 351-352, 664, f. 851
Distribution 691, 720, 740, m. 352
Seed 489, f. 489, 633, 6385
leucanthus, Distribution 740
pilosa 697
Biennial Gaura 718
Wormwood 367-368, 790
Biennials 648, 786, 862
Bigelovia nudata, Trichomes f. 482
Bigelow, Jacob 708, lala Wésyils 7c, 335383
Bignonia Family
Distribution 723
BIGNONIACEAD
Distribution 723
Bindweed, Black 97-99, 663, 677, 789,

study of seed coats

f. 98
Distribution 696, 698,

716, 829,
m. 99
Seed 429, 528-531, f. 429, 526, 528, 529,
530, 531

European 248-250, 663, 665, 777, 787,
844, f. 249, 593, 594
Distribution 719, 727, 7385, m. 249
Root system 651, f. 653
Seed 463, 563, f. 464
Hedge 245-248, 848, f. 246
Distribution m. 246

INDEX

Small syn. European
Wild syn. Black
Birch sp. Distribution 673
Birds destroy seeds 629, f. 636
distribute seeds 629, 636, 859, f.
637, 638
Bird’s-foot Trefoil 734
Seed 815
Birkett 824
Birlingmair, R. H. XII, 657
Bisexual flowers 605
Bishop, J. J. 336-337
Bitter, Dr. 707, 713, 737, 738, 740
Bitter apocks 78-79, 428, 595, 726, 774,

Black Beggar-ticks syn. Beggar-ticks
Bindweed 97-99, 429, 526, 528-531,
677, 696, 698, 716, 789, 829

Cherry, Wild 637
Couch Grass syn. Fine Bent Grass
Henbane 277, 709, 736
Knapweed 664, 725
Medic 190-191, 453, 546-549, 688, 718,
125, 728, 729) 734; 760
Mustard 142, 157-159, 445-446, 541-
543, 605, 696, 70d, Tito. fade os
788, 810, 811, 814
Nightshade 281-283, 471-472, 568-
569, 625, 630, 645, 687, 696, 697,
720, 736, 777, 790
Blackberry, California 175, 694, 703
Distribution 693
Black-eyed Susan 339-340, 689, 787, f.
339

Distribution m. 340
Root system 645
Seed 486, f. 486
Bladder Campion 436, 716, f. 436
Ketmia syn. Shoo-fly
Blade 591, 592, 594, f. 593
Blankinship, J. W. 838, 853
Blatchley, W. S. XIII, 824, 838
Blazing-star, Seed 478, f. 479
Bleakley, J. L. IIT
Blite, Coast, Distribution 746
Bloody Dock 716
Blooming time of plants 786-790
Blue Field Morning Glory 243-245
Grass 6, 8, 58, 657, 658, 659
Distribution 695, 785
Seeds 830, 832, 857
Canada 811-812, f. 688-689
Kentucky 418, 715, 810, 811, 812,
f. 689
Texas f. 639
Lettuce 402-403, 404, 633, 788
Sage 277-279, 759
Vervain 263-264, 469, 689, 690, 719,
(ls Th)
Bluebell Family
Distribution 724
Blue-stem 688, 785, f. 689
Blue-weed 256, 719
Blumer, W. F. 749
Bogue, BE. E. 838
Bohmer, G. R. 838
Bolivia, Weeds of 693
Bolley, H. L. XII, XIII, 766, 824, 825,
826, 834, 839, 847, 860

Boneset 778, f. 813
False
Seed 478, a 479
Boom, J. H. 748

Boot-jack Sort. "Begdamtiens
Boot-jack, Tall 349-351, f. 350
Distribution m. 350
Seed 575-576, f. 577
Borage 256, f. 608
Family 256-263
Distribution 723, 841
Seed 466-468, 564-566
sp. 711

INDEX 817

BORAGINACEAE 4, 256-263, 777
Bibliography 582
Distribution 723
Seed 466-468, 564-566

Boss, Andrew 844, 848

Botanical Gazette XII

Botany, Geographical 687

Bouncing Bet 134, 136, 790, f. 135, 136
Distribution 688, 710, 717, 728,

m. 136
Seed 533-534, f. 835
Boute 740
Bouteloua 785 |
eurtipendula 689

Bowen-Jones, J. 860

Bowman, J. G. III

Boyton, M. F. 855

Bracken syn. Brake

Bract 862

Bracted Plantain 305-307, 474,

572, 720, 740, 810, 814
Verbena syn. Bracted Vervain
Vervain 657, 658, 719, 787

Bracts as seed disseminators 681

Brake 5, 667, f. 694
Distribution 693

Brambles, Distribution 693

Brandegee, T. S. 751, 767

Branched Fleabane 788

Branching Knotweed 789

Brandenberg weeds 845

Brassica alba 444, 776, f. 444

arvensis 155-157, 663, 665, 676,
796, 799, 808, f. 156, 701
Chemical composition 157
Distribution 699, 717, 727,
735, 736, m. 159
eee 444, 445, 543, 810, 811, f. 444,
5.
campestris
Distribution 725
Seed 445, f. 446
hirsuta 842
juncea
Seed 446, f. 446
napus 445, f. 445
nigra 157-159, 776, 788, f.

571,

787,

158, 701

Distribution 696, 717, 725, m. 159
Seed 445-446, 541-543, 776, 810,
811, f. 445, 542
rapa

seed 811, 813
Sinapistrum syn. B. arvensis
Brauneria purpurea f. 666
Breeder’s Gazette 288, 826
Bremen, Flora of 707, 713-714
Brenchley, W. EH. 860
Brendel 765, 766
Brenton, C. R. 801
Brewer, W. H. 769
Briers 794-807
Bristle 863
Bristly Foxtail 22-24, 714, 732
Ox-tongue 497, 498
British Isles, Flora 714, 731, 838
Britton, N. L. 731, 747, 756, 762, 765,
767, 768
Briza media 667
Broad-leaved
Dock syn. Bitter Dock
Gum-plant syn. Gumweed
Broken seed 811
Brome Grass
Annual syn. Soft Chess
Awned syn. Downy
Awnless, Seed 812
Downy 50-52, 787, 819, f. 51, 728
Distribution 714, 715, m. 51
Seed 420, f. 420
Field
Distribution 715
Hairy
Seed 828

734, |

Hungarian
Seed 419, f. 420
Impurities in 674
Smooth syn. Hungarian
sp. 728, 810
Bromus arenarius
Distribution 733
arvensis 715
Distribution 733
brizaeformis, Distribution 728
hirsuta 842
hordeaceus 46-48, 789, f. 47
Chemical composition 46, 48
Distribution 715, m. 57
Seed 419, f. 419
inermis 842
Seed 419, 812, f. 420
mollis f. 599
secalinus 48-50, 788, 819, f. 49
Chemical composition 48, 50
Distribution 715, 733, 736, m. 50
Seed 420, 517, f. oe
tectorum 50- Hil ie
Distribution 714, ie. 787; 728, 733,
819, m. 51
Seed 420, f. 420
Broom 667
Corn
Seed 411, 512-517, f. 512, 518, 514, 515
Corn Millet, Seed 506
Rape 665, 827, 848
Distribution 735
Brown, Edgar 832, 835, 836, 855, 857
Brown Knapweed 725
Bruce, W. 848
Bruckner, W. 848
Bruhl, P. 839
Brush on highways 794, 807
Buchanan, F. 740, 839
Buchanan, R. BH. 834, 858
Buckhorn 301, 303, 637, 665, 786, 787,
96, 799, f. 302
Chemical composition 303

Distribution 692, 696, 697, 698,
720, 762, 843, m. 302
Root system: 645, 654, f. 648, 649

Seed 473, 572, 640, 674, 810, 814,
830, 832, 833, 834, 836, f. 475,
571, 688
Buckhout, W. A. 839
Buckthorn Family, Distribution 824
Buckwheat 74
Distribution 736
Seed 531, 812, f. 526
Family 74-99, 633
Seed 425-431, 525-532
Wild 97-99, 674, f. 98
Distribution m. 99
Seed 429, 528-532, 814, f. 429, 526,
828, 529, 530, 531, 636
Budd, J. L. 839
Buds, Adventitious 651
Buenos Ayres, Flora 702
Buettner, R. 839
Buffalo Berry 310
Buffalo Bur 284, 286-288, 787,
286, 287
Distribution 693, 711, 720,
730, 738, 766, 767, m2. 286
Seed 471, 569, f. 472, 568, 635
Bug-seed, Distribution 737
Bugloss 256, f. 603
Viper’s 468, f. 468
Bulb 863
Bulbous Buttercup 717
Oat Grass 664 -
Bull, C. P. 839
Bull Thistle 372-373, 494, 495, 650, 687,
695, 721, 725, 789
Bulliform cell f. 599
Bunch Flower 66, 788
Common 66, f. 66
Distribution 66, 67

826, f.
722,

878 INDEX
Bur Clover 452, 453, 548, 549, 708, 810, Distribution 716
811, 815, go5. 834 White 126-128, 664, f. 127
Cucumber 737 Distribution 716, m. 128
Bur Seed syn. Stinkseed Seed 810, 814, f. 638
Burchard, O. 583, 827, $55 Canada (Canadian)
Burdock 370-371, 631, 644, 667, 778, Blue Grass 638, 639, 811, 812
USO TS TR TR OE WSs: fb Goldenrod 313- 314, 479, 480, 721, 790,
870, 779 Lettuce syn. Wild Lettuce
Distribution 687, 721, 725, 838, m. ‘Seed investigation 836-837
371 Seed laboratory XII

Root system, 645, f. 648
Seed 493, 576, 577, f. 494, 577, 635
Trichomes f. 371
Burgess, Rev. 746, 760
Burned-over land 805
Burnut, Ground syn. Caltrop
Burrill, T. J. 826, 848
Burs 707
Burtt-Davy, J. 687, 695, 696, 725, 751,
839, 860
Burweed 839
Buscalioni, L. 547, 554, 580-581
-Bush Clover 454, 553-
Honeysuckle 307
Bushy Knotweed 85-86, 431
Bussey Institution 107, 138, 389
Butter and Eggs syn. Toadflax
Buttercup, Bulbous 717
Celery-leaved 849
UE syn. Small-flowered Crow-
oot
Creeping syn.
Family 139-142
Distribution 724
Seed 438, 440
Small-flowered 787
sp. 625, 660, 665, 667, 677,
Swamp 140-141, 787, f. Uy
Distribution Tale mr. 141
Tall, Distribution 717
Seed 440, f. 441
Butterfly Weed
Seed 462, f. 463
Petter aE 215- 218, 718, 790,
216

Swamp Buttercup

736, f. 621

799, 850,

Distribution TS, a7 B82, Ge ae)
Seed 567-558, f. 559

Buttonweed syn. Butterprint

Butz, G. C. 831, 856

Cabbage 142
Club root 680
Gall Weevil 676
Root Fly 677
White Rust 677
Cacalia tuberosa 493, f. 493
CACTACEAE, Distribution 724
Cactus Family, Distribution
“Caesar Weed’ 861
Calais, False, Seed 502,
Colamp er eee epigeios,

724

iis Gi
Distribution

69
California Blackberry 693
Flora 845, 853
Weed leg islation 794
Weeds 708, 712, 725, 755, 757
Callus 863
Caltha palustris, Distribution 736
Caltrop 203-205, 789, 844, f. 204
Distribution 697, m. 205
Family 203-205
Calyx 604, 863
As seed disseminator 630
Camelina sativa 149-151, 788, f. 150
Distribution 700, 717, m. 151
Seed 4438, 544, f. 443, 542

sp. 853
CAMPANULACEAR, Distribution 724
Campbell, J. R. 768

Campion, Bladder
Distribution 716
Seed 436, f. 436

Red 605

Seed legislation 808, 814
Saskatchewan 713
Thistle 67, 379-382, 494, 592,
636, 638, 639, 648, 651, 665, 688,
708, 748-749, 788, 793, 794,
803, 804, 805, 806, 807, 808,
814, 819, 826, 833, 834, 844,
848, 852 .
Weeds 693, 733, 753, 757, 762,
825, 839
Canaigre 74 3
Canavan, B. HE. 755
Candy Grass 43- 44, 788, a 44
Distribution 715, mm.
Seed 417, f. 416
Cannabis indica 697
sativa 70-72, f. 71
Distribution 696, 715, m. 71
Seed 425, 524-525, f. 426, 525
Caper Family 171-174
Distribution 724

Seed 448

CAPPARIDACEAR 4, 171-174
Distribution 717, 724
Seed 448

CAPRIFOLIACEAE 307
Distribution 724

Capsella bursa-pastoris 151-153, 604,

176, TS8t, SLO, f Whee taseoee
Distribution 696, 717, 734, 740,
m, 158 ;
Root system 648
Seed 443, 540-541, f. 448, 542
Trichomes f. 153
Capsule 863
Caragana 180
Caraway 224, 226-227, 776, 787, f. 226
Distribution 709, 719, m. 227

Carbon dioxid 599-600
Carbonic acid 600
Cards sh aWeeooik
Carduus crispus
Distribution 736
lanceolatus syn. Cirsium lanceolatum
natans
Distribution 736
Carex
sp. 678, f. 408
vulpinoidea 788, f. 407
Seed 407, f. 407
Carnation 120
Carolina Cranesbill 555, f. 556
Carpel 618. 863
Carpenter Weed 270-271, f. 271
Distribution m. 271

Carpet Guess: Louisiana, Distribution
72, :
Carpet Weed Family, Distribution 723
Carrier, L. 856
Carrot Family 224-234
Distribution 725
Seed 460-462, 561-562
Root System 648
Wild 227-228, 637, 667, 786, 788, 796,
802, 819, f. 227, 768
Distribution 688, 692, 698, (12,
719, 725, 767-768, 794, m. 228

Seed 461, 562, 640, 833, f: 462, 561,
635, 565
Carruthers, Wm. 848, 860
Carum carvi 226-227, 776, 787, f. 226
Distribution 719, m. 227

INDEX 879

ac W. 745, 746, 753, 762, 763,
CARYOPHYLLACEAE 4, 120-134, 776
Bibliography 582
Distribution 716-717, 724
Seed 435-438, 533-535
Caryopsis 516, 863
Cassia chamaecrista
Distribution 718
occidentalis
Distribution 723
tora
Distribution 723
Cassidy, J. 837
Castilleja integra
Distribution 694
sp. 702
Castor-oil Bean 205, 697, f. 697
Distribution 696
Catalpa speciosa, Seed, f. 63%

Catchfly
Eyening I 437, f. 437
IL 437, f. 437

Distribution 692
Forked 128-130, f. 129
Distribution m. 180
Seed 436, f. 487
Night-flowering 130-132, 790, f. 131
Distribution 716, m. 132
Seed 437, 810, 814, f. 437, 638
Sleepy 788
Distribution 716
Slender, Seed 534-535, f. 535
Small-flowered (S. gallica)
Distribution 725
Virginia, Seed 535, f. 435
Cates, J. S. 839, 852, 861
Catkin f. 606
Catnip 268, 273-274, 777
Chemical composition 273
Distribution 719, m. 274
Root system 654
Seed 469, 566-567, f. 470, 567, 638
Cat’s-ear 696
Distribution 725-728
Cattle foods, weed seeds in 833, 855,
856, 858
Caulicle 863
Cauliflower 142
Cauline leaves 592
Cazaux, L. 848
Cedar, Red 6
Celandine 793
Celery 224
Fly 677
Cell
Aleurone 524, 530, f. 523, 529
Bulliform f. 599
Chlorophyll f. 599
Cross 510, 516, 518, 522, 529, 538,
f. 518, 516, 518, 523, 537
Hpidermal 514, 518, i. 516, 518, 541,
565, 599
Guard 597, f. 598
Malpighian 547, 549, 5538, 554, 564,
567, f. 546, 551, 555, 556, 558, 567
Netted 538, f. 537
Palisade 527, 598, f. 542, 556, 557, 577,
578, 598
Parenchyma 527, 536, f.
561, 566, 568, 571, 578
Selerenchyma f. 555
Sclerotic f. 574. 578
Starch 511, 517, 530, f. 513, 529, 542
Tapetal 616, 871, f. 615
Tube 516, 522, f. 513, 523
Cellulose 863
Celosia cristata
Distribution 696
Cenchrus tribuloides 25-26, 790, f. 26
Distribution 714, m. 26
Seed 412, 517, f. 412, 505

536, 557, 558,

Centaurea cyanus
Chemical composition 673, 674
Distribution 699, 725, 727
Seed 496, 735, f. 497, 688
jacea, Distribution 725
melitensis, Distribution 725
nigra 667
Distribution 725
repens, Seed 834
solstitialis 383-384, f. 384
Distribution 712, 713, 725, 750, m.

384
Seed 496, f. 497
Central America, Flora 731
Placenta f. 619
Cerastium arvense, Distribution 740
nutans 122-123, f. 123
Distribution 716, m. 122
viscosum 122, 787
Distribution 124
vulgatum 122, f. 124
Cereal Grasses, Sale 814
Cereals 814
Ceutorhynehus sulcicollis 676
Chaff 863
Chalaza 863
Chalon, J. 585
Chamomile, Corn
Distribution 735
Seentless, Seed f. 638
Wild 664
Distribution 709
Chapman, G. H. 833, 851, 856, 859
Charles, V. K. 583
Charlock 845, 848, 851
English 155-157, 676, f. 156, 159, 701
Chemical composition 157

Distribution 717, 734, 735, m. 157
Seed 444, 543, f. 444, 542

Jointed 153-155, 853, f. 154
Chemical composition 674
Distribution 696, 699, 717, 735,

736, m. 1595
sp. 664, 668
Diseases 678, 680
Seed 814
White syn. Jointed Charlock
Cheat syn. Chess
Cheeses 219-221, f. 220
Distribution 687, (18, 725, m. 221
Seed 558-559, f. 558
Chemical composition 837
Barley, Little 61, 63
Barnyard Grass 17
Catnip 273
Charlock, English 157
Charlock, Jointed 674
Chess 48, 50
Chess, Soft 46, 48
Clover, Sweet 188, 190
Corn-flower 673, 674
Crab Grass 10
Crowfoot Grass 43
Dock, Curled 75
Dropseed Grass 34-35
Foxtail 19
Foxtail, Green 21-22
Lamb’s Quarters 109
Medic, Black 190
Mustard, Hedge 165
Mustard, Wild. 157
Nettle, Stinging 70
Persicaria 674
Pigeon Grass 19
Pigweed 109
Plantain, Common 299
Purslane 138
Quack Grass 57
Sheep Sorrel 82
Sow Thistle 674
Spurrey 674

Squirrel-tail Grass 60-61

880

Vetch 199
Yarrow 674
Wild Radish 674
Wire Grass 43

Chemical sprays 847, 848, 849, 850,
851, 852
CHENOPODIACEAE 3, 99-113, 633

Bibliography 582
Distribution 716, 724, 743, 747
Seed 431-433, 532-533
Chenopodium album 107-109, 664, 676,
697, f. 108, 695
Chemical composition 109
Distribution 691, 696, 716,
195, 829, m. 109
Seed 432; 532, f. 482, 582
ambrosioides 103-104, 775, 790, f. 104
Distribution 696, 738, 746
anthelminticum 103
botrys f. 105
Distribution 716, 746
glaucum, Distribution 746
hybridum 105-107, 789, f. 106
Distribution 716, m. 107
Seed 432, f. 482
murale, Seed f. 432
rubrum, Distribution 746
urbicum, Distribution 746
Cherry, Black, Wild f. 637
Fire 703
Ground 277, 279-280, 657, 789, f. 280
Distribution m. 280
Root 651
Seed 569
Red, Distribution 694, f. 568
SD. 630, 632, f. 612
Winter f. 623
Chesnut, V. K. 853
Chess 48-50, 788, 819, f. 49
Chemical composition 48, 50
Distribution 692, 715, 733,
m. 50
Seed 420, 517, 814, f. 419
Soft 46-48, 789, f. 47
Chemical composition 46, 48
Distribution 715, 733, m. 47
Seed 419, f. 419
Chestnut, Horse f. 597
Water, Distribution 712
Chickweed 121-122, 629, 661, 663, 786,
; UBUy ifs a
Distribution, 696, 708, 716, 725,
139, MH. 122
Seed 435, 810, f. 435. 635, 638
Mouse-ear 122, 787, f. 123
Distribution 716, 740
Larger, Distribution 124
Nodding 122-123, f. 123
Distribution 122
Chicory 384-386, 778, 789, 7938, f. 386
Distribution 688, 692, 708, 721,
727, 754, m. 886
Seed 496, 579, 814, 836, f. 496, 579,
676, 688, 711
Chile, Seeds 836
Weeds 728
Chilean Dodder 464, 465, 828, 836
Chives 66
Chlorophyll 600, 863
cell f. 599
Chloroplast 598
Christianson, C. & G R. 749
Chromatophore 863
Chrysanthemum leucanthemum. v. pin-
natifidum 362-364, f. 368
Distribution 720, 727, 755, 808, m.
868

729,

736,

Root system 654
Seed 452, f. 492

rust 678

segetum
Distribution 735, 736

INDEX

Chufas 63
ere intybus 384-386, 778, 789,
85

Distribution 712, 721, 727, m. 886
Seed 496, 579, 754, f. 496, 579, 688, 711
Cicuta maculata 230-233, 596, 776, 788,
| el a ye sf)
Distribution m. 231
Seed 460, f. 461
virosa
Distribution 736
Cieslar, Ad 830, 856
Cinquefoil 175-176, 592, 596, 614, 632,
789, f. 176, 638
Distribution 742, m. 176
Seed 448, 449, f. 449
Shrubby 842, 849
Silky, Distribution 734
Silvery syn. Silverweed
Cirsium acaule 667
Distribution 736
alteraceum, Distribution
altissimum 790
Seed 494, f. 495
arvense 379-382, 592, 667, 788, 796,
799, 808, 819, f. 880, 881, 592
Distribution! | 72 ie le eee
736, 748-749, m. 881
Root 651
Seed 494, 810, f. 494
canescens 374-476, 790. f. 874, 875, 749
Distribution 721, 749-750. m. 875
discolor 376-377, 789, f. 876, 377
Distribution m. 3877
drummondii, Distribution 694
drummondii v. acaulescens,
bution 694
eriocephalum, Distribution 694
foliosum, Distribution 694
heterophyllum, Distribution 736
joense 377-379, 789, f. 878
Distribution m. 3878
Seed 495, 578, f. 495, 578
lanceolatum 372-373, 667, 789, f. 878
Distribution 695, 721, 725, 727,
UG, We 2053
Root system f. 650
Seed 495, f. 494
palustre 667
Distribution 736, 748
pratense, Distribution 712
sp. 676. 693
undulatum
Root 651
Seed 495, f. 495
City Goosefoot, Distribution 746
Clammy Weed f. 172
Distribution 717
Clapper, M. 763
Clark, G. H. 24, 57, 59, 76, 80} 9%, i414;
126, 130, 132, 138) da 7149s ble
250, 251, 294, 297, 301, 328, 360,
362, 382, 384, 390, 391, 394, 399,
825, 826, 827, 836, 839, 860
Clarke, G. W. IV, V
Claviceps purpurea 678, 680
Clay soils, Weeds of 819
Claypole, E. W. 703, 706, 839
Cleavers syn. Bedstraw
Cleistogamous flowers 629
Cleome serrulata 173-175, 789, f. 174-

175
Distribution 693, 717, 729, 730, 2.
174
Seed 448, f. 448
Climbing Milkweed 241, 242, 243
Clinton 765
Clinton, G. P. 826, 839
Clotbur 625
Spiny 334, f. 336
Distribution 698, 713, 737, 754, 821
Seed 485-486, f.. 485

736

Distri-

INDEX

Clothier, G. L. 842
Clover
Alsike, Seed 450, 810, 812, 8380, f.
451, 638
Impurities 831, f. 638
Bokhara syn. Sweet Clover
Bur, Distribution 708
Seed 452, 549, 810, 811, 815, 832,
834, f. 453, 548
Bush, Seed 454, 552, f. 454
Crimson
Seed 812, 831
Dodder 250-253, f. oe
Distribution 719, 73
Seed 465, 810, 828, 335, f. 465
Fields, Weeds of 637
Hop 787, f. 184
Distribution 734, 760
Low 183; 184, 185, jin, Est
Distribution WUSse ads 65
Seed 451, f. 451
Japan, Seed 831
June, Seed 812
Meadows, Weeds of 846
Mexican, Distribution 723
Peavine, Seed 812
Prairie, Hairy
Seed 550, “S59, foot
Red, Seed 451, 810, 811, 812, 828,
830, 831, 832, 833, 836, 855, 857,
Ff. U5. 638
Impurities in, 78, 130, 149, 175,
360, 674, 692, 698, 705, 712, 830,
831, 835, 836, 855, 856, 857, 858,
859, f. 674; 726
Mammoth, Seed 811, 812
Medium, Seed 811, 830
Small, Seed 812
Sapling, Seed 812
Sour, Seed 526, f. 526
sp. 6, 67, 180, 624, f. 596, 605, 612
Seed 805, 806, 812, 814, 827, 828,
£30, 831, 833, 836
Stinking syn. Rocky Mountain Bee-
Plant
Stone, Distribution 718, 760
Sweet
sp. Seed 794, 815, 834
White 187-190, 788, 794, f. 188
Chemical composition 188-189
Distribution 718, 725, 729, 760,
m. 189
Root system 645, 648, f. 644
Seed 451, 549, 550, 810, 811, 831,
832, f. 452, 548, 726
Yellow 186-187, 776, 789, f. 186
Distribution 713, 718, 725, 729,
759, m. 187
Seed 452, 810, 813, f. 442, 548
White (T. repens)
_ Distribution 718
Seed 830, 831, f. 451, 638
White (T. agrarium) syn. Yellow
Clover
Yellow, Seed 183-184, 450, f. 451
Club-root of Cabbage 680

m. 185

Cluster-cup, Gooseberry-leaf 678
Pine 678
Cnicus arvensis syn. Cirsium arvense
Coast Blite, Distribution 746
Cockerel, T. D. A. 839
Cockle, Corn 125-126, 665, 776, 789,
19, 829, f. 700
pustebacion 692, 6995. 709, 7116;
MN.
Seed 436, 674, 735, 736, 810, 829,
838, f. 436, 688
Cow, Seed 814
Purple, Seed 814
White, Seed 810, 814
Cocklebur 334-337, 631, 637, 681, 790,
794, 795, 799, 808, 822, 839, 850,
Ife $35, 682

881

Distribution 720,
Root System 645
Seed 485, f. 485
Dagger 794
Spined syn. Clotbur
Cockscomb
Distribution 696, 736
(Cfowhe, di, TD, ey)
Colburn, F. EH. XII
Colchicum 66
autumnale 667
Distribution 736
Collman, C. 748 :
Collomia grandiflora, Distribution 737
Colonists, Plant 696
Colorado Beetle 667 . higit
Grasses 837 21 EAN
Weeds 745, 747, 748, 755, 157, 759
Coltsfoot 663, 664, 665
Distribution 735, 736
Coma 629, 631, 864
Combs, Robert 745
Comfrey, Common 256, f. -635
Distribution 719
Wild (Cynoglossum boreale)
Seed 466, f. 466
NE es virginianum) 258-259, f.
Distribution m. 259
Seed 564-565, f. 565
Commerce aids in scattering seeds 687-
688, f. 688
Common alien plants 697-698
Complete flower 604, f. 604
ComEsas 4, 307, 404, 638, 701, 788,
7
Bibliography 582, 583
Distribution 720-721, 724, 747-756
Inflorescence 614, f. 613
Seeds 477-502, 574-580
Composite Family syn.
Family
Cone-flower
Distribution 720, 737
Seed 486, f. 486
Gray- headed, Seed 486-487, f. 487
Purple f. 666
Connecticut Experiment Station XII
Legislation 794
Seed investigations 830
Weeds 766
Conium maculatum 709, 776,

m, $35 .

tyr oOTT

Sunflower

f. 710

Distribution 712, 719, 728, 136,
768-769.
Conringia orientalis 160-162, 592, 788,
f. 161, 162

Distribution m. 162
Seed 446, f. 446
Constantinesco, A. 582
CONVOLVULACEAE 4, 241, 254
Bibliography 583
Distribution 719, 724, 756-757
Seed 463-465, 563-564
Convolvulus arvensis 248-250, 663, 665,
He, NESS freee
Distribution 719, 727, 735, 1736,
756-757, m. 249
Root system 651, f. 658
Seed 463, 563, f. 464, 563
Family 241-254
Seed 463-465, 563-564
sepium 245- 248, 7871, f. 246
Distribution 691, 719, 740, m. 246
Root system 652, f. 651
Seed 464, 564, 810, f. 464, 563
Cook; ln ©: 340
Coral Honeysuckle 307
Coralberry syn. Indian Currant
Cordemoy, J. de.
Coreopsis 307, 489, 689
Distribution 838

882

palmata 689
tinctoria
Distribution 740, 844
Corispermum hyssopifolium 698
Distribution 737
Corn 368, f. 505
Seed 813
Broom 512
Seed 514, f. 513, 516
Chamomile, Distribution 735
Cockle 125-126, 665, 776, 789, 819,
$29, f. 125, 700
Distribution 692, 699, 709, 716, 735,
736, 829, 838, m. 126
Seed 436, 810, f. 436, 688
Crowfoot 663
Fields, Weeds of 692, 845, f. 24, 661,

663
Gromwell 262-263, 787, f. 262
Seed 467, f. 468
Kaffir 8
Marigold, Distribution 735, 736
Mint 665

Poppy 735, f. 618
Speedwell 723
Spurrey, Distribution 813
Sweet, Seed 813
Cornell University 673
Corn-flower 677
Chemical composition 673, 674
Distribution 735
Seed 496, 814, f. 497, 688
Trichomes f. 497
Corolla 604, 864
Corymb 612, 864
Cosmopolitan weeds 695, 736,
777, 786
Cosmos 307
bipinnatus, Distribution 696
Cotta, H. 840
Cotton 213
Thistle 667
Distribution 725
Cotyledons 623, 864
Couch Grass 851
Black 664
Coulter, J. ©. 747, 757
Coverdale, F. 187
Coville, F. V. 840
Cow Cockle 814
Parsnip 234, f. 2384
Seed f. 561, 562
Cowbane 230-233, 683, 776,
282, 233
Distribution 736, m. 2381
Seed 460, f. 461
Spotted 596
Cow-herb 132-134, 789, f. 133
Distribution 692, 696, 697, m. 134
Seed 438, f. 438
Cowpea 180
Cox, H. R. 8389, 848, 861
Crab Grass, Common 8-10,
C905. 75. 8
Chemical composition me
Distribution 714, 731, mm.
. Root system 647
Seed 409, f. 409, 676
Smooth 10-12, f. i
Distribution 714, m. 12
Seed 408-409, 810, Ff. 409
Sprouting 14-15. f. 15
Distribution 691, 714, m. 15
Seed 410, f. 410
Craig, M. 840
Cranberry marshes, Weeds of 846
Crandall, C. S. 755, 826
Crane, O. B. 848
Cranesbill, Carolina 555, f. 556
Wild, Distribution 718

757, 763,

USB, js Col

731, 785,

INDEX

CRASSULACEAE, Distribution 724
Craty, Ra Sr 745, 748, 749, 751, 759,
760, 766, 767
Crawford, A. F. 763
Creeping ‘Buttercup 141
Charley syn. Ground Ivy
Soft Grass 665, 667
Spurge 208, 209, 458
Verbena syn. Prostrate Vervain
Cremocarp 864
Cress, Marsh 167-168, 787, f. 167
Distribution 742, m. 168
Seed 447, f. 47
Seed 441, f. 441
Water 142
Distribution 717
Winter 170, 677, f. 270
Distribution 717, 733, 740, mm. 171
Seed 447-448, f. 47, 542, 544
Crimson Clover 812, 831
Crocker, Wm. 829, 856
Cropping, continuous, Effect of 684
Cross cell, see Cell, Gross 5
Crosby, J. C. 840
Crosby, M. L. 836
Crotalaria sagittalis 182-183, 788, f. 182
Distribution 718, m. 183
Seed 545-546, f. 546
Crowfoot, Distribution 742
Corn 663
Family syn. Buttercup Family
Grass 41-43, f. 42
Chemical composition 43
Distribution 732, m. 42
Seed 416, f. 416
Small-flowered 139, f. 139
Distribution 717, m. 140

Seed 440, 536, f. 449, 586
Crown 654
Crownbeard, Seed 575. f. 577
Crozier, A. A. 766, 825
Crucifer 677, 785, f. 606

CRUCIFERAE 4, 142, 170, 634, 776, 819
Bibliography 583
Distribution 717, 724
Seed 441-448, 539, 544
Crusaders distributed weeds 700
Cryer, J. 840
Cucumber, Bur, Distribution 737.
Wild 573, f. 574
CUCURBITACEAE, Distribution 724
Seed 573
Cudweed. Distribution
Culm 864
Crystalloids 864
Cunningham, J. C. VII, XII, 641
Cup. Plant, Seed 482, f. 488
Curled Dock 74-76, 426-427, 630, 647,
652, 654, 660, 696, 697, 716, 725,
727, 736, 774, 788, 794, 796, 799,
805, 810, 814, 834
Currant f. 612

720, 741

Indian 307, 790, f. 308
Distributien m. 808
Quntiss Ca neve

Cuscuta arvensis 252- 254, 789, f. 28
Distribution 712, 719, 729, m. 252
Seed 810

chilensis, Seed 465, f. 465
epilinum f. 253
epithymum 250-253
Distribution 712, 719,
m. 257

725, 729, 735,

Seed 465, 564, 810, f. 465, 564
euronaea 852
sp. 850
Seed 828, 829
Cusick, Wm. 694, 726, 751, 840

Cutler. Manasseh 708, 711

Cvyclachaena xanthifolia 332

one atriplicifolium 99-101, 788,
. 100

INDEX 883

Distribution 716, 740, m. 100

Seed 431, f. 431, 730
platyphyllum syn. OC. atriplicifolium
Cyme 614, 864

Cynara cardunculus 701
Cynodon dactylon
Distribution 732
Cynoglossum boreale 787
Seed 466, f. 466
officinale 256-257, 777, f. 257
Distribution 719, m. 257
Seed 466, f. 466
virginianum 258-259, f. 259
Distribution m, 259
Seed 564-565, f. 565
sp. f. 635
CYPERACEAE 3, 63, 407-408, 636
Distribution 715, 724
_ Cyperus esculentus 63, 790, f. 64
Distribution 696, 697, 715, m. 64
rotundus 63
Distribution 722, 723
Cypress Spurge 718, f. 735
Distribution 736
Cypripedium acaule 702
Cystopus candidus 677, 678

Dactylis glomerata
Distribution 715
Seed 417, 811, 813, f. 417
Dagger Cocklebur 794
Spanish, Root system 645
Dahmen, Max 580
Daily, C. HB. 749 -
Daisy 362, 665, 667, 677
Fleabane 322-324, 657, 658
Distribution 720
Seed 482, f. 481
Trichomes f. 482
Ox-eye 362-364, 667, 793, 794, f. 363
Distribution 704, 720, 727
Root system 654
Seed 492, f. 492, 638
sp. f. 595
Dakota Vetch 761
Dakota
North, Flora 839
Seed investigation 834
Weed legislation 794, 806-807
Weeds 744, 757
South
Weed legislation 794, 808
Weeds 744, 756, 757, 767
Vetch 761
. _ Weeds 693, 753
‘\Dalea alopecuroides 192-193, 790, f. 192
Distribution 718. 790, m. 793
Seed 453, 550, 552, f. 454, 551
Foxtail syn. Dalea
laxiflora
Seed 454, f. 454
Distribution f. 454
Pink, Seed 454, f. 454
Dandelion 386-389, 592, 604, 629, 633,
657, 659, 664, 676, 773, 780, 786,
787, 814, 819, 843. 850, f. 78, 386,
887, 388, 389, 623, 743
Chemical composition 389 :
Distribution 630, 696, 697,
708, 721, 743, 838, m. 387
Root system 648, 654
Seed 490, 579, f. 498, 580
Dark-seeded syn. of
Red-seeded 390-391, 787, f. 396
Distribution 721
Seed 498, f. 498, 631
Sivall-flowered syn. Red-seeded Dan-
delion
Danger, L. 736, 753, 819, 848
Danish Seed Control Station 828
Dark-seeded Dandelion syn. Red-seeded
Dandelion

704,

Darlington, Wm. 756, 760, 761, 762,
67, 820, 822, 826, 840
Darnel, Distribution 692, 699, 715
Poison 52-53, f. 52
paseo ute 696, 699, 715, 736, m.

5.
Seed 522-524, f. 520, 521, 5238, 524
Datura stramonium 288-291, 777, 788,
f. 290, 709
Distribution 696, 720, 736, 767, m.
290
Seed 471, 569, f. 472, 568, 624
tatula 288-291, 777, 787, f. 289
Distribution 697, 720, m. 289
aacusy cane te 227-228, 788, 796, f. 227,
768

‘
Distribution 698, 712, 719, 725,
767-768, 796, 802, 819, m. 228
Seed 461, 562, f. 462, 561, 635
Davis Weed 218
Day Nettle 664
Dead Nettle 665, 719, 723, 727, 822
Deadly Nightshade 736

Delaware
Weed legislation 794
Weeds 765

De Loach, G. B. 856

Delphinium consolida
Seed 439, f. 459
penardi 142, f. 142
Seed 439, f. 439

' Denmark Weeds 7538, 766, 795, 844

Seed investigations 828
Deschampsia flexuosa
Seed f. 639
Desmodium canescens 690
Des Moines Capital 803
Determinate inflorescence 610-614
Devol, W. S. 831, 856
Dewey, L. H. 396, 708, 744, 745, 795,
825, 826, 840, 848, 856, 860, 861
Diamond-back Moth 677
Dibble, W. 851
DICOTYLEDONEAR 3, 67-404
Dicotyledons 623, 864
Dicots 67-404
Didlake, M. L. 857, 860
Digitalis
Distribution 693
purpurea
Distribution 227, 736
Digitaria humifusa 10-12, 789, f. i1
Distribution 691, 714, m. i2
Seed 408-409, 505, 810, f. 409, 505
saneuinalis 8-10, 790, f. 9, 11, 731
Chemical composition 10
Distribution 691, 714, 731, m. 9
Root system 647
Seed 409, f. 409, 676
Dioecious plants 605
Dioscorides 773
DIPSACEAE
Distribution 724
Dissemination, Burs 256
by woollen mills 2038 /
Dock, Bitter 78-79, 595, 789, f. 79
Distribution m. 79
Seed 427, 726, f. 427
Bloody, Distribution 716
Broad-leaved syn. Bloody Dock *
Curled 74-76, 660, 774, 788, 794, 796,
799, 808, f. 7h, 76, 630, 727
Chemical composition 75
Distribution 652, 696, 697,
725, m. 75, 736
Root system 652, 654, f. 647
Seed 426-427, 810, 814, 834, f. 426,
638
Pale, Distribution 716
Patience, Distribution 763
Peach-leaved syn. Smooth Dock
Red-veined syn. Bitter Dock

716,

884 INDEX
Smooth 76-78, 787, .794, 796, 799, Eclipta alba, Distribution 756
Hfotlits ths Economic plants 853

Root system 654
Distribution m. 77
Seed 427, f. 427
Sour syn. Curled Dock
sp. 592, 630, 649, 660, 665, 667, 676,
678, 687, 734, 773, T74
Seed 832
Tall. See Curled Dock
Yellow. See Curled Dock
aeder 645, 665, 688, 838, 839, 850,
52

Alfalfa 252
Seed 810
Chilean
Seed 465, 828, 836, f. 465
Clover 250-252, f. 251, 252
Distribution 719, 725, 729, m. 251
Seed 465, 564, 810, 828, 835, f.
465, 563, 638, 726
Lesser f. 253
Field 252-254, f. 253
Distribution 719, 729, m. 254
Seed 464, 810, f. 464
- Max fi, od
Perennial 843
sp. 645, 692
Seed 640, 814, 833, 834, 856, 857
Thyme f. 253
Dodson, W. R. 840
Dog Grass 774
Dog Fennel sun. Mayweed
Dogbane Family 234-237
Distribution 723
Spreading 235, 237
Distribution 719, m. 235
Dooryard Knotgrass syn. Knotweed
Bnew era 84-85, 428, 659, 716, 736,
2
Plantain syn. Common Plantain
Dooryard weeds f. 25
Dormant period 786
Dorph-Petersen, K. 828, 856
Doryphora decemlineata 677
Downy Brome Grass 50-52,
715, 728, 819
Dragon Root f. 596
Drains clogged by weeds 682
Dropseed Grass 785, 790, 850
Seed 834, f. 676
Mexican 32-34, 660, f. 33
Chemical composition 34-35
Distribution 715, m. 33
Seed 413-414, f. 414
Drug plants 853
Preparing for market 780-781
Raising 773, 780-781, 854, 855
Drugs, Root 853
Drysdale, J. 851
Duggar, J. F. 853
Dunean, J. H. 768
Duvel, J. W. T. 835, 856
Dyer’s Green Weed 667
Distribution 718
Dyssodia chrysanthemoides syn. of
papposa 356-358, 789. f. 357, 358
Distribution 705, 720, 755, m. 3857
Seed 490-491, f. 497
@richomes f. 491

Earnshaw, G. T. 851

Haton, A. J. 848

Echinochloa crusgalli 16-17, 790, f. 16
Chemical composition 17
Distribution 714, 731, m. 16
Seed 411-412, 506. f. 411, 505, 729

Hehinocystis lobata, Seed f. 57%

Echinospermum lappula syn. Lappula

echinata

Echium vulgare 468, f. 468

Distribution 719

420, 714,

Edson, H. A. 848
Edwards, A. H. 763
EKelworm,
Egg, 620, f. 621
Eegg-case 617
BHegert, Henry 747, 766
Ehinger, G. E. 756
Bhrhart, F. 840
Bichornia crassipes, Distrintiont 712
EXLATINACEAE

Distribution 724
Eleagnus f. 602

Elder, Marsh 332-334, f. 833, 752
Distribution 70, "739, 751-753, m.
333
Seed 482, 814
Elecampane

Distribution 709, 720 .

Bieochars palustris, Seed 407-408, f.

#

Eleusine indica 41-43, 788, f. 42
Chemical composition 43
Distribution 696, 698, 715, 733
Seed 416, f. 416

Elliott, W. B. 763, 767

Elkweed
Distribution 694, 840

Ellisia, Common 255-256, f. 250

nyctelea 255-256, f. 255
Distribution 719, m. 256

Elm 69
Distribution 695

Elodea canadensis
Distribution 740

Embryo 621-623, 624, 864, f. 622

Sae 620, f. 620, 621

Endive, Wild 793

Endosperm 865

England, Weeds of 763

English Charlock 155-157,

DABS TOde seliiem atte
Plantain syn. Buckhorn
Rye Grass syn. Perennial Rye Grass

Envelopes, Floral 609, f. 609

Epicarp 865

Epichloe typhina 677

Epiderm 865

Epidermal cell. See Cell, Epidermal

Epidermis 597, f. 598

Epigaea, sp. 702

Epigynous flowers 610, f. 611

Epilobium angustifolium
Distribution 693, 694, 726, 741

hirsutum ;
Seed 829

roseum
Seed 829

sp. 703

spicatum
Distribution 840

EQUISETACEAE 3, 6

Equisetum arvense 5, 6, f.
Distribution 736, m. 5

palustre 849
Distribution 736

HBradication. of weeds 846-853

Also see species

444, 542,

5, 6

Eragrostis pilosa 45-46, 789, f. 44
Distribution 715, 732, m. 46
Seed 417, 740, f. 416
Pilose syn. Spear Grass
Erechtites hieracifolia 368-369, 778,
789. f. 869
Distribution 695, 721, m. 869

Seed 492, f. 492
sp. 703
HBrect Knotweed 8?, 83, 429, 526, 696,
(16; 25; 89
Ergot 680, 814, 815, f. 689
Rye 678

INDEX

Erica arborea, Distribution 693
Erigeron acris
Distribution 741
annuus 321-322, 595, 788, f. 321, 621
Distribution 695, 720, 737, m. $22
Seed 482, f. 481
cinadeneis 322-326, 660, 664, 778,
Distribution 690, 695, 696, 698,
704, 720, 736, 737, 754, 819, m. 826
Seed "482, fe 481
ramosus 391. 322-324, 788, f. 823
Distribution 720, m. 824
Seed f. 481 ,
sp. f. 621
Hrodium cicutarium 457, f. 457
Distribution 725, 729, 734
,moschatum
Distribution 713, 725
Musk
Distribution 713, 725
sp. 711
Eruca sativa 159-160, f. 159
Distribution 712, m. 160
Ervum lens 554
Eryngium
sp. Distribution 701
Bbyeian cheiranthoides, Distribution
il

Erysiphe graminis f. 682
Escholtzia, Distribution 725
Eskech, J. N. 766
Hsparcette 831
Essential organs 605, 615
EXUPATORIACEAE 693
Eupatorium perfoliatum 778
purpureum 780
Seed 477, f. 478
Trichomes, f. 478
urticaefolium 312-313, 780, 789, f. 312
Distribution m. 813
Seed 477, f. 478
Trichomes f. 478
villosum 477
Trichomes f. 478
Euphorbia corollata 210, f. 2i/
Distribution 690, 718, f. 211
cyparissias 212-213, 819, f. 212, 735
Distribution 712, 718, 736, m. 213
Seed f. 557
exigua 664
geyeri, Distribution 690
maculata 208-209, 586, 788, f. 209
Distribution 690, 718, m. 209
Seed 458, 557, f. 457
marginata 210-211, 787, f. 210, 712
Distribution 712, m. 211
Seed 458, f. 458
peplus 819
preslii 207-208, 787, f. 207
Distribution 718, m. 208
Seed 458, 556-557, f. 438
sp. 660
Distribution 705
JXUPHORBIACEAE 3, 205-213
Bibliography 583-584
Distribution 718, 724, 757
Seeds 457-458, 556-557
Buropean Bindweed 248-250, 563, 653,
BOS's, BGs Tals 7 Vela Bag VO,
777, 787, 822, 844
Morning Glory syn. Bindweed
Weeds 703, 704, 706, 7138, 731, 732,
733, 734, 748
European weeds from America 737-740
Evans, Dr. 681

Evans, M. W. 836
Evening Catchfly I 437
Catchfly II 437
Primrose 224, 225, 460, 560, 592, 645,

885

690, 696, 718, 737, 762, 776, 788,

819
Family 224-225, 460, 724
Ewart, A. J. 187, 829, 837, 840, 856
Everlasting, Distribution 740
Explosive seeds 629, 631, 634

Fagopyrum esculentum
Distribution 736
Seed 531, f. 526
Fahlenkamp, H. R. 749
Fallow field, Weeds of 661

False
Acacia 718
Boneset 478, 479
Calais, 501, 502

Flax 149-151, 443, 542, 544,
788, 793, 815
Small-fruited 638

Lettuce 500

Strawberry 175-176
Farmer’s Review 188, 250, 826
Farwell 753
Fawcett, H. S. 746, 835, 856
Fendler 751, 767
Fern, Boston 5

Maidenhair 5

Shield 5
Fernald, M. L. XI, 687, 702, 709, 710,
714, 731, 750, 754, 767, 768, 840.
Ferns 5-6
Fertilization 620-621, f. 620, 621
Double 621
Fescue
Grass 785
Seed 827
Meadow
Distribution 715
Seed 418, 810, 811, 813, f. 418
Sheep’s
Distribution 715
Festuca elatior 418, f. 418
elatior pratensis
Distribution 715
Seed 811, 813
ovina
Distribution 715
pratensis syn. F. elatior pratensis
Fetid Marisela 356-358, 490-491, 755,

700, 717,

Feverfew, Distribution 734
Feverwort 778
Fiber plant 861
Fibrovascular bundle 865
Field Brome Grass 715
pode 252-254, 464, 719, 729, 789,
Larkspur 439
Marigold syn. Corn Marigold
Mint 665
Pennycress 1438, 814
Sorrel 202-203, 630, 734, 741

Sow Thistle syn. Perennial Sow
Thistle
Thistle syn. Prairie Thistle
Fig 69

Figwort Family syn.
Filament 615
Fine Bent Grass 664, 665
Finger Grass Syn. Crab Grass-
Fink, Bruce 755, 762, 763
Fir, Dcuglas, Distribution 694
Oregon, Distribution 694
Fire, Flora following 693-695, 702, 703
Fireweed 368-369, 703, 778, 789, f. 869
Distribution 695, 721, m. 369
Seed 492, f. 492
Mexican 101-103, f. 102
Distribution 714, 716, 746, m. 103
Seed f. 433
Northern 694, 703
Distribution 726, 741
Fitzpatrick, F. J. 766

Mullein Family

886 INDEX

Five-finger syn. Cinquefoil
Tall 657
Flax, Common
Seed 456, 554-555, 810, 813, f. 456,
BD)
Impurities in 692, 744, 839
Dodder f. 253
False 149-151, 788, 793, f. 750
Distribution 700, 717, mM. Lot
Seed 443, 544, 815, f. 4438, 542
Small-fruited, Seed t. 638
Family, Distribution 724
Mustard 155
Fleabane 321-322, 788, f. 321
Distribution 695, TOM TRIG Wits 84
Seed 482, f. 481
Branched syn. Daisy Fleabane
Daisy 322-324, 657, 658
Distribution 720
Seed 482, f. 481
sp. 741, f. 621
Fletcher 749
Fletcher, James 24, 57, 59, 76, 80, 97,
111, 126, 130, 132, 138, 147, 149,
151, 250-251, 294, 297, 301, 328,
360, 362, 382, 384, 390, 391, 394,
766, 825, 826, 839
Flora Cestrica 766
Floras
Australia 696, 731, 733, 734, 763
Boston 708-709
Bremen 707, 713-714
British Isles 714, 731, 838
Buenos Ayres 702
California 845, 853
Central America 731
France 713, 731, 837, 846
Germany 731, 841
Italy 731, 838
Missouri 954
Montana 838, 853
Nebraska 845
New England 709, 714
New South Wales 731
North Carolina 854
North Dakota 839
Ohio 723
Oklahoma 838
Oregon 694
Pampas 701
Plymouth 845
Tennessee 853
Vienna 843
Westchester, Pa. 766
West Indies 731
Wisconsin drift 689-692
Yucatan 731
Floral axis 611
envelopes 609, 610, f. 609
Florida, Weeds 762
Florula. Bostoniensis 708-709
Mlowering plants 6-404
Spurge 210, 211, 556, 557, 690, 718
Flowers 604-625
Apetalous 609
Axillary 611
Bisexual 605
Complete 604, f. 604
Hpigynous 610, f. 611
Funnel-shaped f. 611
Gamopetalous f. 608
Hypogynous 610, f. 606
Imperfect 605
Irregular f. 605
Morphology of 604-625
Perfect 605, f. 604
Perigynous f. 610
Pistillate 605, f. 606, 607
Solitary 611, f. 611
Staminate 605, f. 606, 607
Sterile f. 607
Strap-shaped f. 611
Tubular f. 611

Fliickiger, F. A. 580
Fly Beetle 676
Cabbage-root 677
Celery 677
Frit 677
Mangold 676
Foeniculum capillaceum 702
Fogel, Estella D. 861
Food plants become weeds 712
Fool’s Parsley 663, 736
Forest vegetation 693
Forget-me-not 664
Forgrave, Caroline 824
Formaldehyde 600
Foultes, P. H. 848
Four-leaved Grass 693
Fournier, Hug. 583
Four-o "clock
Distribution 696
Family 119-120, 533
Wild 119-120, 660, 787, f. 120
Distribution 716, m. 120
Seed 533, f. 534
Foxglove
“Distribution 693, 727, 736
Wild Yellow 702
Foxtail
Bristly 22-24, 790, f. 22, 28
Distribution 714, Be
Grass syn. Marsh Foxtail
Green 20-22, 506-511, 657, 790, f. 21,
507, 509, 510, 665
Chemical composition 21-22
Distribution 691, 714, 729, 731

Seed 412-413, 834, f. 412, 511, 512,
676
Marsh, Distribution 715, 732, 740, f.

782
Meadow, Distribution 715
Slender 665
sp. 664, 732, 850, f. 217, 662
Whorled sun. Bristly
Yellow 17-20, 22, 657, 658, 659, 660,
CSO Vin, 18; 28)
Chemical composition 19
Distribution 691, 714, m. 19 .
Seed 22, 413, 511, 512, 616, f. 473;
676
Fracker, S. B. 478, 479, 481, 487, 489
Fragrant Goldenrod 690
France, Flora 713, 731, 837, 846
Weed legislation 795
Weeds 753, 754, 763
Frank, A. B. 580, 820
Franseria discolor, Distribution 730
Seed 485, f. 484
Hookeriana 485, f. 484
Hooker's 485, f. 484
White-leaved 485, f. 484
Freeman, G. F. 831, 859
Freight cars, Weeds distributed by 794
French, C. 841
French, G. T. 833, 834, 859
Frenchweed (Thlaspi) 794
Distribution 717
(Galinsoga) «Distribution 736, 753
Fringed Gentian 702
Frit Fly 677
Wruit 624-625, 865
Fruwirth, C. 820, 856
EUMARIACEAE
Distribution 724
Fumitory 665
Family, Distribution 724
Fungi destructive to weeds 852
harbored by weeds 677-678
Funicle 865
Funnel-shaped flowers’ f. 611
Galeopsis tetrahit, Distribution 720,
2A
Galinsoga parviflora

Distribution 7138, 736, 737, 7538-754

INDEX 887

Galium aparine 572, 663,
Distribution 741
_ Seed 476, f. 476
sp. 693
trifidum
Distribution 741
Gall Weevil, Cabbage 676
Turnip 676
Galloway, B. T. 838
Gamopeétalous flowers f. 608
Garber 766
eearcke, E: 707, 731, 737, 738, 740, 754,

1
Garden Orach 735
Pink 120
Garden and Forest 725
Gardens, Weeds of 58-59, 93
Garlic 66
Wild 67, 787
Garman, H. 832, 848, 857, 860
Gattinger, A. 766, 853
Gaura, Biennial, Distribution 718
biennis 789.
Distribution 718
Genista tinctoria 667
Distribution 718
Gentian, Closed 689
Fringed 702
Gentiana andrewsii 689
George, EH. L. 749
Georgia Weeds 754
GERANIACEAE 634
Distribution 718, 724
Seed 457, 555-556, 634
Geranium f. 602, 624
earolinianum 555, f. 556
Family 457
Distribution 724, 734
maculatum, Distribution 718
Gerardia, sp. 702
Gerdts, C. L. 582
Germander, American 272-273, 789, f.
273
Distribution m. 273
Seed 469, f. 470
Germany, Flora 731, 841
Weed legislation 795
Weeds 713, 735, 736, 753, 766, 820,
841, 845
pceuinaion of Seeds 24, 99, 856, 857,
(85

Standards 835

cee 835, 837, 855, 856, 857, 858,
Gesneria f. 619
Geum canadense 180, 788, f. 187

f. 573

Distribution 717, m. 181
Seed 449, 545, f. 440, 545
Geyer, C. A. 374, 767

Ghost Moth 677

Giant FAVSEOD. : Seed HOM Yio Bor

Gibbons, W. P. 85

Gilia squarrosa 840

Gillanders, F. 851

Ginseng 781, 854

Gland 865

Gleditsch, J. G. 841

Globoids 865

Glossary 862-872

Glover, G. H. 848

Glume 865

Glyevrrhiza lepidota 196-197, 787, f. 196
Distribution 718, 729, 760, m. 197
Seed 554, f. 551

Gmelin, J. FE. 841, 848

Sena ae uliginosum, Distribution

20, il

Goat Weed, Distribution 736

Goat’s Beard, Distribution 696, 729

Godfrin, H. 581

Goessman. C. A. 837

Goff. E. S. 371, 824, 825, 826, 841

Golden Seal 854

Goldenrod, Canadian 313-314, 790, f.
31

4
Distribution 721, 737, m. 314
Seed 479, f. 480
Fragrant 690
Large Yellow-flowered 316-317, 689,
790, f. 317, 633
Distribution 738, m. 317
Seed 480, f. 480
Late syn. Smooth Goldenrod
Smooth 315, 316, f. 315
Distribution m. 316

Seed 480, f. 480
sp. 6, 307, 592, 594, 645, 681, 689,
737, 738
Stiff syn. Large Yellow-flowered
Goldenrod

Goldflus, M. 582
Gonolobus laevis 241, 242-243, 789, f.
243
Distribution f. 243
Goodspeed, C. M. 854
Goose Grass syn. Crowfoot Grass
Gooseberry-leaf Cluster-cup 678
Goosefoot, City, Distribution 746
Family 99-113, 633
Distribution 724, 743-747
Seed 431-433, 532-533
Maple-leaved 105-107, 789, f. 106
Distribution 716, m. 107
Seed 432, f. 482
Oak-leaved
Distribution 746
Gorse 667
Gourd Family, Distribution 724
Graham, C. H. 746
Grain fields, weeds of 699-700
GRAMINEAE 3, 7-63
Bibliography 584
Distribution 714-715, 724, 757-759
Seeds 407-424, 506-524
Grass
Annual Brome, syn. Soft chess
Annual Meadow 660, 664
Awned Brome, syn. Downy Brome
Grass
Awned Wheat 715
Awnless Brome 812
Barley 667
Barnyard 16, 17, 330, 412, 505,
(29, Tal
Beard 722, 862
Bent 664, 667
Bermuda 732
Black Couch Grass syn.
Grass
Blue 6, 8, 58, 638, 639, 657, 658, 659,
695, 715, 785, S11, 812, 830; 832,
857
Blue-stem 688, 689, 785
Bristly Foxtail 22-24, 714, 732, 790
Brome sp. 728, 819
Bulbous Oat syn. Pearl Grass
Candy 43-44, 416, 417, 715, 788
Carpet 722
Cheat syn. Chess
Chess 48-50, 419, 517, 692, 715, 733,
736, 788, 819
Couch 851
Crab 8-10, 409, 647,
785, 790
Creeping Soft 665
Crowfoot 41-438, 416, 732, 788
Dog 774
Downy Brome 50-52, 420, 714, 715,

728, 819
790, 834, 850

Dropseed 676, 785,

English Rye 811

Family 7-63, 407-424, 506-524, 584,
623, 636, 645, 677, 714- 715, 724,
757-759, 785

Fescue 785, 827

Field Brome 715

506,

Fine Bent

676, 714, 731,

888

Fine Bent 664, 665

Finger syn. Crab Grass

Four-leaved 693

Foxtail syn. Marsh Foxtail Grass

Goose syn. Crowfoot Grass

Green Foxtail 20-22,° 412, 418, 510,
Bibile yalBe air, 665, 676, 691, 714,
M29, Tol, 90

Hair 790

Hairy Brome 828

Holy 27-28, 693, 741, 787, 814

ERR arian 506

Hungarian Brome 419, 420

Italian Rye 421, 787, 811, 813

Johnson 7-8, 722, 805, 853

Land, Weeds of 665-667

Little Barley 61-63, 424, 715, 812

Long-awned Poverty 29-30

Low Spear 664, 715

Marsh Foxtail 715, 732, 740

Marsh Muhlenberg’ 35- 37, 413

Meadow 660,

693 ;
Meadow Fescue 418, 715, 810, 811,

$13
Meadow Foxtail 715
Mexican Dropseed 32-35,

660
Needle 666-667, 689, 790
Nimble Will 30-33, 735
Nut, Northern 63, 64, 696, 697, 715,
741, 790
Southern 63, 722, 723
Oat 810, 81

413-414,

8138
Old-Witch 12-14, 410, 660, 676, 706,

714, 740

Onion Couch 851

Orchard 417, 715, 810, 811, 813, 828,
832, 857

Pampas 8

Pearl 664, 665

Perennial Rye 420, 421, 789, 811, 813

Pigeon 17-20, 22, 413, 640, 676, 714,
732, 814

Porcupine syn. Needle Grass

Poverty 28-29,

Powdery Mildew on 682

Quack 8, 27, 53-58, 241, 2738, 421-
423, 640, 6438, 648, 651, 664, 665,
674, 680, 688, 715, 736, 773, 774,
781, 786, 794, 796, 810, 819, 822,
844, 847, 848, 850

Quaking 667

Quick syn. Quack Grass

Red Top 415, 680, 715, 805, 806, 810,
811, 813

Reed 733, 736

Reed Bent 693, 736

Rib syn. Buckhorn

Ribbon 8

Rice Cut 739, 740

Rough-stalked Meadow 639, 715

Rye 785, 789, 810

Sandee 25-26, 412, 517, 637, 714,

Seribner’s Panic 660, 689

Scutch syn. Quack Grass

Seed Impurities 832, 834, 855, 856,
857, 858, 859

Sheathed Rush 37-38, 715, 790

Sheep’s Fescue 715

Side Oats 689

Silky Bent 639

Skunk-tail syn. Squirrel-tail

Slender Foxtail 665

Slender Wheat 53, 57, 422, 428

Small Squirrel- tail 787

Small Rush 388-39, 715, 790

Smooth Brome syn. Hungarian
Brome Grass
Smooth Crab 10-12, 408-409, 505,

714, 789, 810
Soft Chess 46-48, 419, 715, 733, 789

INDEX

Southern ppedt 45-46, 416, 417, 715,
T22, 4

Sprouting Crab 14-15, 410, 691, 714

Squirrel-tail 58-61, 678, 679, 680,
691, 693, 715, 729, 730, 788

Stink syn. Candy Grass

Sweet Vernal 693, 714

Switch 6, 410, 411

Tickle syn. Old Witch Grass

Timothy 414-415, 517, 638, 676, 715,
ee 805, 806, 810, 8138, 827, 832,

Tussock 667
Twitch 851
Vanilla syn.
Velvet 693
Wall Barley 698
Western Wheat 53, 56, 423, 715
Wild Barley syn. Squirrel-tail Grass
Wild Oats 40-41, 415-416, 664, 665,
674, 679, 715, 736, 789, 793, 810,
314° 829
Wire 41- 43, 418, 697, 715, 741
Wood Hair Grass 639
Woolly Soft 665
Yard syn. Crowfoot Grass
Yellow Foxtail 17-20, 22, 4138, 511,
512, 657, 658, 659, 660, 676, 691,
714, 789
Yorkshire Fog 665, 667
Grasses of Cornfields 17
Gravelly Soils, Weeds of 819
Gravis, A. 582
Gray, Asa 687, 704, 707, 714, 722, T47,
(dil, 7535. (D4, 91555 Lo Geonames
760, 761, 762, 767, 768, 820, 841
Gray-headed Cone-flower 486-487
Grayson, J. 749
Great Britain, Weeds of 660, 663-664
Greater Ragweed 326-327, 645, 691,
720, 789, 814
Green Foxtail 20-22, 412-413, 506-511,
512, 657, 658, 659, 660, 665, 676,
Gels Wale Was Wek, TOW
Greene, EH. L. 841
Greene, L. C. 247
Greene, M. L. 848
Greenish, H. G. 853
Greif, O. 841
Griffith, M. C. 749
Griffiths, D. 848
Grindelia 307
Sealy 780
squarrosa 780
Distribution 730, 756
Seed 479, f. 480
Grisdale 836
Grisebach, A. H. R. 731
Gromwell, American
Seed 467, f. 467
Corn 262-263, 787, f. 262
Distribution 262-263
Seed 467, f. 468
Ground
Burnut syn. Caltrop
Cherry 277, 279-280, 568, 569, 657
Virginia 279, 281
Ivy 275, 276, 594, 608, 719
Groundsel 660, 663, 678
Distribution 693, 125, (35, a6
Seed 493, f. 493
sp. Distribution 694
Guard cell f. 598
Guerin, M. P. 584, 586
Guignard, L. 581
Gulf States, Weeds of 722
Gum-plant sun. Gumweed
Gumweed. 307
Broad-leaved
Distribution 730, 756
Seed 479
Giissow, H. T. 849
Guttenberg, H. V.

Holy Grass

583, 828

INDEX 889

GYMNOSPERMAE 3, 6, 404
Gymnosperms 6-404

Haberlandt, G. 585
Hackberry 69
Hadrome f. 598
Haglund, H. 841, 849
Hair Grass 79
3 Distribution 732
Plant 603
Hairy Brome Grass 828°
Hedge Mustard 544
Prairie Clover 550, 551, 552
Vetch 455, 718
Hale, T. J. 751
Halfbreed Weed syn.
Hall 751
Hall, A. D. 664
Hall, J. M. 749
Halsted, B. D. 80, 680, 758, 765, 766,
767, 826, 841, 849, 861
Haltica syn. Phyllotreta
Hamburg Seed Control Station 827, 856
Hamill, Ss. Oe 755
Hammond, R. FEF. 832
Hanausek 538, 575, 581, 584
Hanbury, D. 580
Hanover Weeds 753
Hansborough, Senator 826
Hare’s-ear Mustard 161-162, 592, 788
Seed 446, 814, 815, f. 447
Harpel, L. V. 755
Harper, R. M. 702, 841
Harrington, G. T. 834, 857
Harrison, #. C. 841
ialelinny (Gia. Mh iL
Hartig, Th. 841
Hartweg 766

Harvey 751
Harvey, F. L. 826, 832, 841, 857
Harz VC. Ds 5385) bab, 539). DAT, bbs,
575, 583, 582, 583, 584, 585, 586,
587, 827, 830, 857
Havard, V. 751
Hawkbit 664
Distribution 721
Hawkweed 678, 840, 843, 845
(Hieracium), Distribution 750
Seed 502, f. 502
(Senecio), Distribution 754
Orange 842, 846, 849
Distribution 712, 750
Seed 502, 814, f. 502
sp. 846
Hawthorn, Distribution 695
Hay fever caused by pollen 681
Hayden 767
Hayden, Ada VII, XII, 627
Hayne, F. G. 853
Hays, W. M. 825, 842
Hazel f. 606
Distribution 693, 695
Heal-all_ syn. Self-heal
Hedge Bindweed 245-248, 848
Mustard 164-165, 446-447, 543-544,
659, 664, 677, WALT 725, 787
Heileman, W. iE, 837
Helenium autumnale 354-356, 780, 790,
f. 255, 356
Distribution mv. 255
Seed 490, f. 491
tenuifolium f. 721
Distribution 722
evaaiius annuus 340-342, 596, 601,

Marsh Hider

89, fF. S41, 342
Die rion 693, 730, 740, 756,
nr. 3841
Seed 487, 575, f. 487, 576
Trichomes f. 488
' grosseserratus 344-346, 790, f. Sy,

845
Distribution 691, m. 345
maximiliani 348-349, 790, f. 348
Distribution m. 348

occidentalis, Distribution 689, 690
Trichomes 478, f. 488

petiolaris 342-343, 788, f. 343
Distribution 730, m. 343
Seed 487, f. 488
Trichomes f. 488

strumosus, Seed 488, f. 488

tuberosus 346-348, f. 346, 347
Distribution 740, m. 347?
Trichomes 487, f. 488

Heliopsis scabra 338-339, f. 338

Distribution 720, m. 339
Seed 486, f. 486

Heliotrope, Wild, Distribution 695

Helminthosporium gramineum 677, f.
680

Hemlock 6

Poison 709, 776, f. 7120
Distribution 719, 728, 768-769
Water syn. Cowbane
Hemp 69, 70-72, 665, f. 7
Distribution 696, 697, 715, m. 71
Seed 425, 524-525, f. 425, 525
Indian 235-237, f. 286
Distribution 719, m. 237
Root 651
Nettle, Distribution 720, 727
Water 118-119, 789, f. 118
Distribution 716, m. i119
Seed 435, f. 435
Wild, Root system 645
Hemsley, W. B. 731
Henbane 677
Black 277, 709
Distribution 736
Hen-bit f. 595
Henderson, L. F. 826, 842
Henfrey, A. 743, 861
Henkel, Alice 771, 853, 854
Henry, W. A. 82 6
Henshaw, H. W. 629
Henslow, J. S. 714
Hensman, R. 829, 857
Hepialus luperli 677

Hepner, EF. E. 61, 188, 837

Heracleum lanatum 234, f. 234
Seed 562, f. 561

Herb 865

“Herball” 773

Hermaphrodite 866
Herr, Bertha XII
Hexham Scent 843

Hibiscus trionum 221, 222, 790, 796,
802, f. 222, 761
Distribution GOO, OM, ile, Wale,

718, 761-762, m. 222
Seed 460
Hicks, F. H. 857
Hicks, J. F. 831, 859
Hieracium aurantiacum, Distribution
750
Seed 502, f. 502 ‘
canadense, Seed 502, f. 502
floribundum, Distribution 750
sp. 678 4
Hierochloe borealis 27-28, 787, f. 27,
742
Distribution 741, m. 27
odorata syn. H. boredlis
Higbee 765, 766
Highways, Weeds on 799- 800, 805, 806,
807, 808
Hilgard, Eugene 725
Hill, HE. J. 842
Hillman, FE. H. XII, 464, 584, 826, 831,
836, 842, 855, 857
Hiltbrummer, John "157
Hiltner, L. 828
Hilum 865
Hinager, P. H. 757
Hitchcock, A. S. 250, 650, 707, 745, 746,
MAO RED Ose Depo sik OOsen Olemat ols
826, 842

890

Hitier, H. 849
Hoarhound syn. Horehound
Hoary Alyssum 147-149
Vervain 264-266, 469, 659,
Hock 707
Hodge 824
Hodson, E. R. 761
Hofmeister, W. 581
Hogenson, J. C. 849
Hogweed syn. Smaller Ragweed
Holecus lanatus 667
mollis 667
sp., Distribution 693
Holland Weeds 763
Hollyhoeck 213
Holm, Th. 584, 854
Holt, F. L. 861
Holy Grass 27-28, 787, f. 27, 742
Distribution 693, 741, m. 27
Seed 814
Honey Locust 180
Honeysuckle, Bush 307
Coral 307
Family, Distribution 724
i oXo)<¢-) a ee DiS a)
Hooker’s Franseria 485, f. 484
Hooper, L. J. 767
Hop Clover 787, f. 184
Distribution 734, 760
Low 1838, 184-185, f. 185
Distribution 718, 745, 761, m. 185
Seed 451, f. 451
Hops 69, f. 602
Hordeum, caespitosum, Distribution

jubatum 58-61, 788, 808, f. 59, 60,758
Chemical composition 60, 61
Distribution 691, 715, 729, 730,

(a 59, wo. G0
Seed 4238, 519-520, f. 424, 505

murinum 677, 698, 701

pratense 667

pusillum 61-63, 787, f. 62
Chemical composition 61, 63
Distribution 715, m. 62
Seed 424, f. 424

secalinum 701

Horehound, distribution 720, 728
Seed 470, f. 470, 729
Horse Chestnut f. 597
Nettle 67, 247, 283-285, 637, 777, 786,
US, WOE. W995, SF, S88 SHO, jc
285, 638, 765
Distribution 720, 765-766, 844, m.
285
Root 651
Seed 471, 568, 630, f. 472, 568
Sorrel syn, Sheep Sorrel
Horseradish 168-169, 788, f. 169 .
Distribution 700, 712, 717, m. 169
Horsetail 667, 819, f. 5.
Distribution 736, m. 5.

719, 789

Family 6
sp. 736
Horseweed 324-326, 657, 659, 660, 664,
778, 819

Distribution 324, 695, 736,
"31, (a45, Wis 1826
Root system 645
Seed f. 481
Horton, H. HB. 842
Hosackia purshiana, Distribution 761
Hound’s Tongue 256-257, 777, 787, f.
257
Distribution 719, m. 257
Seed 466, f. 466
Howitt, J. EH. 826, 842
Humus Soils, Weeds of 819
Hundeshagen, J. G. 842
Hungarian Brome Grass 419, 420
Grass 506
Hungary, Weeds of 754, 843
Hunter, Robert 801

690,

INDEX

Hutcheson, T. B. 856

Hutchinson, A. 766

Hutton, G. 850

Hyacinth 66

Hyaline layer 516

Hyams, C. W. 854

HYDROPHYLLACEAE 4, 254-256
Distribution 719

HBL RCODIC movement in seeds 629,

A 36

Hyosecyamus niger, Distribution 736
HYPERICACEAE 4, 221, 223-224
Distribution 724
Hypericum perforatum 223-224, f. 228
Distribution 788, 841, m. 224
Hypochaeris radicata 696
Distribution 725, 728
Hypoderm 516, 865
Hypogynous flowers 610, f. 605
Hyssop, Giant, Seed 567, f. 470, 567

Idaho Weeds 745, 757, 842, 844
Illinois weed legislation 794, 803-804
Weeds 745, 751, 757, 765, 766
Immigrant weeds 743-769
Imperfect flowers 605
Indeterminate inflorescence 610, 866
India Weeds 767
India-rubber tree 69
Indian Currant 307, 308, 790
Hemp 235-237, 651, 719
Mallow 215-218, 557-558, 559, 687,
elo Zen MOO
Mustard 446
Plantain 493
Indiana weed legislation 804
Weeds 747, 757, 766, 768, 838
Indians, Plants disseminated by 687
Indigo Plant, Distribution 734
Indigofera hirsuta, Distribution 734
Inflorescence 610-614, 866
Catkin f. 606
Composite 614, f. 613
Corymb 612, 864
Cyme 614, 864
Determinate 610, 614, 864
Head 612, f. 612, 613
Indeterminate 610, 866
Mixed 610
Raceme 611, 869, f. 612
Spike 611, 870
Umbel 612, 871, f. 618, 614
Insects and weeds 674, 676-677
Integuments 619, 624, 866
Internode 866
Inula helenium, Distribution 720
Involucre 614, 866
as seed disseminator 631, 633

Iowa Homestead 284, 288, 334, 335,
391, 826

Seed investigations 834-835

Seed legislation 809-814

Thistle 377-379, 495, 578, 789

Tumbleweed 116, 631

Weed legislation 794-801

Proposed law 801-803

Weeds 840, 841, 844, 845, 851

Tpomoea hederacea 243-245, 789, f. 248

Distribution m. 245
purpurea f. 244, 245
iiseribution! 696, m. 2!
Seed 463, 564, f. 464, 5
Treland, Weed laws 79
Weeds of 846
Tris f. 617
Ironweed 309-310, f. 309
Distribution m. 310
Seed 477, f. 477
Western 310-311, 594, 790, f. Sil
Distribution m. $811
Seed 477, f. 477
sp. 807
Trregular flowers f. 605
Tsle- “of- man, Weed laws 793

5)

}
63

INDEX 891

Italian Rye Grass 421, 787, 811, 813
Italy, Flora of 731, 838
Iva xanthifolia 332-334, 789, f. 838, 752
Distribution 332 720, (29,
7538, 844, m. 383 3
Seed 482
Ivy 645
Ground 275-276, 787, f. 275, 594, 608
Distribution 719, m. 276
Kenilworth -
Distribution 727
Poison 213,£214, 683, 787,
215, 683
Distribution m. 214
Root system 652
Poisoning 780, Antidote 780

Jagger, Mary G. 830

James, EH. 766

Tamestown Weed syn. Jimson Weed

Japan Clover 831

Jasmine f. 608

Jenkins, H. H. 21, 43, 70, 107, 138, 190,
299, 303, 364, 389, 581, 830, 837,
842, 857

Jerusalem Oak, Distribution 716, 746

Jimson Weed 277, 288-291, 471, 683,
ee UUs 788, f. 289, 72, 608, 62h,

Divtvipation 687, 696, 720, 736,
767, mm, 290
Seed 569, f. 568
Joe Pye Weed 594
Seed 477, f. 478
Trichomes f. 478
Johnson, A. G. 849
Johnson, Cc. V. 748
Johnson, F. 829
Johnson, L. 854
Johnson, T. 857
Johnson Grass 7, 8, 805, 853, f. 722
Distribution 722, 732, m. 722
Jointed Charlock 153- 155, 673, 6/74,
GOS. TAN Bb
Jolliffe, Te B. 749
Jones, J. W. 74%
Jones, i. RR. 838, 842, 849, 857
Jones, M. BE. 751 :
Josselyn, John 710, 711
Joxe, A. 581
Juhlin-Dannflet, H. 849
Jumelle 584
JUNCACEAE 3, 63, 65
Distribution 715
Juncus balticus 820
tenuis 63, 65, f. 65
Distribution 115, 741, nt. 65
June Clover 812
Junowicz, R. 581
Jussiaea suffruticosa, Distribution 734

Kabsch, W. 693, 699, 754, 767, 842
Kalter, G. M. 842
Kansas
Seed investigations 831, 832
Weed legislation 794, 805
Weeds 708, 751, 754, 756, 757, 766,
837, 842
Kay, GF AICI, We
Keel 866
Kellerman, W. A. 723
Kellerman, W. A. Mrs. 723
Kellogg, Harriette, WANE Sanh: Wis, TTA,
817, 824, 854

843, f. 244,

Kelsey, J. A. 751, 849
Kenilworth Ivy, Distribution TET
Kentucky Blue Grass “418, 639, 715,

810, 811, 812
Seed investigations 832-833, 857
Weed legislation 794 ;
Weeds 747
Ketmia. Bladder sun. Shoo-fly
Key for families 3-4
Key, Sothoron 835. 857

Khaki Bush 846
Kieffer, 713, 737
Kienitz, M. 828, 858
Wing, Charlotte, Vil, XII, 406, 782, 817,
824, 834, 83 5, 845, 850, 858
King Islands Melilot syn. Yellow Sweet
Clover
Iinghead 847
Kinzel, W. 828, 858
Kirk, T. W. 849
Klein, F. A. 760
Klugh, G@. F. 854
Knapweed 383-384, 667, f. 383
Distribution 699, Tilse DE,
1. 3883
Seed 496, f. 497
Black 664
Distribution 725
Brown
Distribution 725
Spiny syn. Knapweed
Knight, H. G. 61, 188, 837
Knotgrass 663
Seed f. 638
Dooryard 788
Knotweed, Branching 789
Bushy 85-86
Distribution m. 86
Seed 431, f. 431
Dooryard 84-85
Distribution 659, 716, 736, 742, m.
S84

Ses 428, f. 428
Hrect 82- 83, 789, f. 838
Distribution 696, (U6, 725, f. 82
Seed 429, f. 429, 526
Face syn. Bushy
sp. 665
Larger syn.
Knowlton, C. H. 842
Koch, G. D. J. 754
Kochia scoparia 101-103, 789, f. 102
Distribution 714, 716, 746, 844, m.
103
Seed f. 433
Kolkwitz, R. 858
Konigsberg, Hxperiments at 673
Korsmo, EK. 661, 658
Korsoms, B. 849
Kraemer. A. 854
Krafft, G. 827, 842
Kraus, G. 539
Kraus, O. 849
Krutizky 584
Kuhnia eupatorioides
Seed 478, f. 479
Trichomes f. 479
Kunze, Otto 702
Kuntze, R. BE. 858

750,

Hrect Knotweed

LABIATAE 4, 268-278, 777
Bibliography 584
Distribution 719-720, 724, 759
Seed 469-570, 566-567
Lactuca canadensis 399, 401, 780, 788,
f. 400, 401
Distribution m. 401
Seed 500. f. 500
floridana, Seed 500. f. 500, 633
pulchella 402-403, 788, f. 408
Distribution 729
scariola 396, 596, 664, 790, 819

Distribution 721, 725, 729, 747,

758, m. 398 _

seariola integrata 396-399, 721, 747,
if Ire

Distribution m. 398
Seed 500, f. 501
Lady Slipper, Stemless 702
Lady’s Sorrel 659, 787
Distribution 696, 697, 718
Seed 456, f. 457
Thistle, Distribution 725

892

Thumb 93-95, 664, 665, 736, 788, f. 94
Chemical composition 677
Distribution 691, 716, m. 95
Seed 430, 527, f. 430, 526

Lambert 740
Lamb’s Quarters 107-109, 594, 658, 659,
660, 676, 697, 788, f. 108, 695
Chemical composition 107, 109
Distribution 687, 691, 696, 716,
725, 729, m. 109
Seed 432, 532, f. 432, 588, 638, 676
Western, Seed f. 432
Lamella 866
Lamina 866
Lamium album,
amplexicaule,
727

sp. 736
Lamson-Scribner, F, 842
Lance-leaved Ragweed 483
Salvia 277, 278, 279, 759
Langethal, C. HE. 842 j
Lappa syn. Arctium
Lappa officinalis syn. Arctium lappa
Lappula echinata 260-262, f. 261
‘ Distribution 719, m. 262
Seed 466, 565-566, f. 467, 566
virginiana 259-260, 788, f. 259
Seed 466, f. 467
Large Peppergrass 143, 144-145, 442,
539-540, 542, 717, 738, 787
Ragweed syn. Greater Ragweed
Spotted Spurge 660, 718
Large-bracted Vervain syn. Prostrate
Vervain
Larger Knotweed syn. Erect Knotweed
Mouse-ear Chickweed 124
Larkspur, Field, Seed 439, f. 439
Prairie 142, f. 142
Seed 439, f. 439
Larsen, O. H. 849
Laschke, W. 858
Late Goldenrod syn. Smooth Goldenrod
Lathyrus aphaca f. 598
Laubert, R. 698, 849
Laurus canariensis, Distribution 693
Lavialle, P. 582
Lazenby, W. R. 843, 857
Leaf, Alternate 594, f. 593
Arrangement 592-594
Arrow-shaped f. 594
Branching 594-597
Cauline 592
Cleft 596, f. 595
Compound 596
Crenate 596, f. 596
Dentate 595, f. 4595
Entire 594
Function 599-601
Kidney-shaped f. 594
Lobed 596, f. 584, 594
Morphology 591-598
Netted-veined 592
Opposite 5938, f. 593
Ovate f. 595
Parallel-veined 592
Parts 591-592, f. 598
Pinnate f. 596
Pinnatifid 596, f. 595
Primary 591
Protection 602-603
Radical 592
Reniform f. 594
Secondary 591
Sessile 592, f. 592
Serrate 596, f. 595
Serrulate 596, f. 595
Spear-shaped f. 594
Spiny-pointed f. 595
Toothed 595
Transpiration 601-602
Triangular f. 594

distribution 727
distribution 719, 723,

INDEX

veuinS 592
Wavy 594, AE 595
Lee, L. V. 750
Leek 66
Leersia oryzoides f. 739
Distribution 740
Lees, J. H. XII, 755
Legislation, Weed 794-808
LEGUMINOSAE 4, 180-199, 776, 819
Bibliography 585-586-
Distribution 718, 724, 759-761
Seed 450-455, 545-554, f. 551
Leguminous weeds 667, 785
Lehmann, BE. 713, 737, 858
Leonard, J. 766
Leontodon autumnalis, Distribution 736
Leonurus cardiaca 276-277, 777, 788,
6

(fae CHE
Distribution 720, m. 277
Seed 470, f. 471
Lepachys pinnata 486-487, f. 487
. Distribution 737
Lepidium apetalum 146-147, 787, f. 146
Distribution 692, 717, 734, 741, m.

Ly?
Seed 441, 540, f. 442, 541, 688
Sativum 441, f. 441

sp. f. 598

virginicum 144-145, 787, f. 15

Distribution 717, 738, 844, m. U5
Seed 442, 539-540, f. 442, 542
Leptochloa mucronata, Distribution

723

Leptome f. 598
lesage, P. 829
Lespedeza capitata, Seed 545, 552, f. 4a4
sp. 850
stuvei 552
Lettuce 307, 633
Blue 402-403, 788, 7. 408, 633
Distribution 729, m. 404
Canadian syn. Wild Lettuce
False, Seed 500, f. 500
Prickly 396-399, 596, 645, 664, 790,
819, 826, 838, 840, f. 398
Distribution) V2), V2 beekeeioes
840, m. 398
Root system 645
Seed 500-501, f. 501
Prickly (integrata) 396-399, f. 397
Distribution 721, 747, m. 898
Seed 500, f. 501
Wild 399- 401, 130, 88, SOM peeues
401, 595
Distribution 838, 810, 846, m. 898
Root system 645
Seed 500, f. 501
Leunis, Johannes 754
Liatris gracilis 478
punctata, Seed 478, f. 479
Trichomes f. 479
Light, Effect on germination 829
Ligule 867 ‘
LILIACEAE 3, 66-67
Distribution 715, 724
Lilicoya 693
Lily 6, 66
Easter f. 698
Family 66-67
Distribution 724
of-the-valley 66
Philadelphia 689
Lilium philadelphicum 689
Limy Soils, Weeds of 819
LINACEAE, Distribution 724
Seed 456, 554-555
Linaria cymbalaria, Distribution 727
vulgaris 292-294, 808, f. 293
Distribution 696, 712, 720, 727,
788, m. 294
Seed 473, f. 473
Linnaeus, see Linne
Linne, C. V. 744, 748, 826

INDEX

Linum usitatissimum 554-555, f. 595
Seed 456, 813, f. 456

Liquorice, Wild 196- 197, 787, f. 196
Distribution 718, 729, 760, m. 197
Seed 554, f. 551

Lithospermum angustifolium, seed 467,

f. 467
arvense 262-263, 787, f. 262
* Seed 467-468, f. 468
latifolium, Seed 467, f. 467
Little Barley 61-63, 424, 715, 812
Live-forever 712
Lloyd, F. E. 843
Loamy Soils, Weeds of 819
Lobe 867
Lobelia 689
spicata 689
Lochrie, G. R. 749
Lockhead, W. 841
Loco Weed, Purple 194-195, f. 195
Distribution 838, 845, m. 195
Seed 454, 552, f. 454, 551
Stemless syn. Purple Loco Weed
Locule 618-619, 867
Locust f. 596
Honey 180
Lodge-pole Pine 694, 695
Lolium italicum 421, 787, f. 421
Seed 811, 813
perenne 52, 701, 789
Distribution 715
Seed 420, 811, 813, f. 421
temulentum 52- 53, 520, noe,
Distribution 696, 699, wiles, Wax,

Sead 522-524, f. 520, 521, 522, 523, 524
Wone erie. 660, 661, 671, 673, 674,
Ors 8 825, 843, 850

Long, J. 767
Long, Wm. 749
Long-awned Poverty Grass 29-30
Long-fruited Anemone 439
Lotus corniculatus, Distribution 734
qouistane. Carpet- “Grass, Distribution
Weeds 840
Louthan 745
Low Hop-Clover 184-185, 451, 718, 761
Senna 723
Spear Grass 464, 715
Lucerne syn. Alfalfa
Luhn 827
Lumen 867
Lummis, G. M. 22, 858
Lundell, J. 750
Lupine 180
Lychnis alba 126- 128, 664, f. 127
Distribution 716, ™. 128
Seed 810, f. 4387
dioica 126, 605
Distribution 716
githago syn. Agrostemma githago
vespertina syn. L. alba ,
Lygodesmia juncea 403-404, f. 404
Distribution 721, 788, m. 404
Rushlike 403-404, . 404,
Distribution m. 404

McAlpine, A. N. 850
McCarthy, Gerald 830, 832, 858
McCarty, C. S. 767
McClanahan, Dr. 749

McCoy 749
McCready, A. B. 837, 843, 850
McKee, Roland 836

McMahon, J. J. 745

MeNair, A. D. 850

Madder Family. Distribution 724

Maiden, J. H. 843

Maine seed investigation 832
Seed legislation 809, 814, 860
Weeds 750, 754, 757, 841

Maize 687
Transpiration of 671, 673

893

Mallow, .Common (M. rotundifolia)
219-221, 596, 787, 822, f. 220
Distribution 708, 718, 725, Mm, 221
Seed 460, 559- 560, - 599
a ee (Sylvestris), Seed 558-559,
Family 213, 215-222
Seed 459-460, 557-560
Indian 215-218, 790, 822, f. 216, 217,
713
Distribution 687, 713, m. 216
Seed 557-558, f. 659
Small-flowered, Distribution 725
sp. 725
Malpighian Cell. See Cell Malpighian
Malva borealis, Distribution 725
erispa, Distribution 725, 776, 787
rotundifolia 219-221, 596, f. 220
Distribution 708, 718, 725, m. 221
Seed 460, 559- 560, f£. 559
sylvestris, ‘Seed 5S, fi. 909
MALVACEAE 4, 213, 215-222
Bibliography 586
Distribution 693, 718,
761-762
Seed 459-460, 557-560
Malzew, A. 829, 843
Mammoth Red Clover 811, 812
Man, Seed disseminated by 629, 687
Mangold Fly 676
Manilla substitute 216:
Manisurus granularis, Distribution 723
Manitoba weed law 793
Weeds 693
Manure, Weed seeds in 833
Many-flowered Aster 317-318, 689, 790
Maple 6, 630, 632
Distribution 695
Soft, Seed f. 634
Maple-leaved Goosefoot 105-107,
Walt 1839)

724, 1734,

432,
Marigold, Common, Distribution 696
Corn, Distribution 735, 736
Fetid 356-358, 789, f. 357, 858
Distribution 720, 755, m. 357
Seed 490-491, f. 491
Field syn. Corn Marigold
Marsh, Distribution 736
Marjoram, Wild, Distribution 693
Marl Soils, Weeds of 819
Marre, E. 850
Marrubium vulgare, Distribution 720,
C255 MAS
Seed 470, f. 470, 729
Marsh Cress 167-168, 447, 742, 787
Hilder 332-334, 482, 720, 751-753
Foxtail 715, 732, 740
Marigold 736
Muhlenberg 35-37, 413
Marshall, Humphrey 765, 766
Martin, TeNe WAG S2<10L, 589
Maryland seed investigation 833
Weed legislation 794°
Weeds 833, 844
Martynia Family, Distribution 724
MARTYNIACEAE, Distribution 724
Massachusetts seed investigations 833
Weeds 750, 754, 757, 763, 842
Matthews, J. B. 748
Matricaria discoidea syn. M. suaveolens
inodora 664
suaveolens, Distribution 705, 714,
Mattirolo, O. 547, 554, 581, 585
May Apple 618
Mayne 824
Mayweed 360-362, 778, 788, f. 361
Distribution 687, 696, 736, m. 362
Root system 645
Seed 491, f. 491, 638
Meadow Fescue 418, 715, 810, 811, 813
Foxtail syn. Marsh Foxtail

894 INDEX

Grass 660, 693
Annual 664
Rough-stalked 639, 715
Rue 438-439, 688
Saffron 736
Salsify 497, 498
Sunflower 344-346, 487
Meath, R. S. 766
Mechanical devices as aids to _ seed
scattering 629, 630, 631, f. 630,
631, 632, 633
Medic, Black 190-191, f. 191
Chemical composition 190
Distribution 688, 718, 725, 728,
(29, T34as C6L, mm. 197
Seed 453, 546-549, f. 453, 578
Medicago denticulata 549, 702
Distribution 725, 729
Seed 549, 811, 832, f. 549, 729
hispida, Seed 452, f. 543
lupulina 190-191, 787, f. 191
Chemical composition 190 —
Distribution 718, 725-728, 734, 761,

, 546-547, 549, 810, 811,
- 831, Ff. 458, 548
sativa, Seed 811, 812
Medicinal Plants 307, 77

Absinth 307
Agueweed 780
Bindweed 777
Boneset 774, 778
Burdock 778, 779
Butterfly Weed 774
Caraway 709, 776
Catnip 777
Chamomile 709
Chickweed 776
Chicory 778
Corn-Cockle 776
Cowbane 774, 776’
Dandelion 773, 780
Docks 774
Hlecampane 709
Evening Primrose 776
Heverwort 778
Fireweed 778
Fleabane 778
Golden Seal 854
Grindelia 790
Hemlock, Poison 709, 776

Water 776

Wild 774
Henbane, Black 709
Horse Nettle 777
Horseweed 778
Hound’s-tongue 777
Jimson Weed 709, 777
Joe-Pye Weed 774, 790
Lettuce, Wild 780
Mallow 776
Mayweed 774, 778
Milkweeds 777
Motherwort 777
Mullein 774, 777
Mustard, Black 776

sp. 773

White 776
Nightshade, Black 777
Peppermint 709
Plantains 778
Pokeweed 776
Quack Grass 7738, 774, 775
Ragweed 778
Self-heal 777
Sheep Sorrel 774
Snakeroot 780
Sneezeweed 790
Sweet Clover, Yellow 776
Tansv 307. 709. 773, 780
Thorn Apvle 774
Vervain 777
Water Pepper 775

3-789, 853-855

Wormseed 774, 775
Yarrow 778
Mediterranean Weeds 696
Medium Red Clover Seed 812, 830
Melanthium virginicum 66-67, 788, f. 66
Distribution m. 67
Melhus, J. 749
Melica, Distribution 701
Melilot, King Islands syn. Yellow Sweet
- Clover
Melilotus alba 187-190, 788, f. 188
Chemical composition 188, 190
Distribution 718, 725, 729, 760,
m. 189
Root system 645, f. 644
Seed 451, 549-550, 810, 811, 832,
. 452, 548
officinalis 186-187, f. 187

Distribution 713, 718, 725, 729, 759,
Mm. 187

Seed 452; 550, 776, 810; SLE fe 2525
a4

parviflorus syn. M. officinalis
sp. 853
Menault, E. 843
Mentha arvensis 268, 663
Distribution 736, 741
arvensis v. canadensis 268-269, f. 269
Distribution m. 269
piperita 268, f. 270
Distribution 720
spicata 268, 789
Distribution 720
viridis, Distribution 728
ny Three-seeded 205-207,
2)
ee 718,
Seed 457, 457
Merrill, S. A. tig
Mesocarp 518, 528, 867, f. 523, 528, 529
Starchy 516, f. 513
Mesophyll 578, 867, f. 529
Mexican Clover 723
Drop-seed Grass 32-34, 413-414, 660,

(3 Saale
m. 207

715, 790
Wireweed 101-103, 433, 714, 716, 746
Poppy 839
Tea 103-104, 738, 746, 790
Mexico, Weeds of 733, 767-768 .

Meyer 538
Michel XII
Michigan seed investigations 830
Weed legislation 794
Weeds 708, 757, 766,
830-831, 838, 855
Micropyle 867
Mignonette Family, Distribution 724
Migration of Weeds 687-769, 837-846
Mikania scandens 847
Mildew, Downy 678
White 85
Milk Purslane syn. Creeping Spurge
Spurge syn. Creeping Spurge
tainted by weeds 683
Vetch 193-194
Milkweed, Climbing 241, 242-2438, f. 242
Distribution mm. 243
Common 239-241, 788. 794, f. 289, 240
Distribution 691, 719, m. 240
Root eee 651, f. 646
Seed 462, 562-563, f. 463, 562, 632
Family 23 37- 241, 633
Seed 462-463, 562-563
Showy 237-238, 787, f. 2388
Distribution 719, m2. 238
sp. 631, 777, 807, 850
Swamp, Seed 462, f. 463
Whorled, Seed 463, f. 468
Millet, Broom Corn, Seed 506
Common, Seed 411, 506, 813, f. 411, 505
Hog, Seed 813
Pearl, Seed 813

768, 824-825,

INDEX

Whorled, Distribution 732
Seed 413, f. 412 °
Mills, J. H. 766
Millspaugh, C. F. 731, 774, 778, 843,
50, 854
Milwaukee weed legislation 808
Minnesota medicinal plants 855
\ Weed legislation 794, 805-806
Weeds 745, (eile 53, "757, 844, 845,
8
Mint 268-269 f. 269
Distribution 736, 741,
Corn 665
Family 268-278
Distribution 724, 759
Field 665
sp. 728
Mirabilis jalapa, Distribution 696
Mississippi Valley weeds 751, 769
Missouri Flora 854
Medicinal plants 854
Weed legislation 794, 806
Weeds 754, 757, 759, 766
Mistletoe 645
Mixed inflorescence 610
Moeller, J. 520, 522, 575, 581, 584
Moesz, G. 843
Mohr, Dr. Charles 707, 722
Mollugo verticillata, Distribution 704
Moninger, W. R. 768
Monocotyledon 867
MONOCOTYLEDONEAE 3, 6-67
Monocotyledons 623
Monocots 6-67
Monoecious plants 605
Monolepis nuttalliana, Distribution 693
Montana Flora 838, 853
Weeds 757, 838
Moore, C. 731, 733, 734
Moore, G. T. 834
Moore, R. A. XII, 382, 850
Morning Glory, Annual 245-248, f. 244
Distribution 696, m. 245
Seed 463, 5645 f. 464, 563
Blue Field 243-245, f. 243
Distribution m. 245
European 248-250, 787, 822, 850, f. 249
Distribution 710, 740, m. 249
Root f. 653
Family 241-254
Distribution
Seed 563-564
Perennial 250
Wild 241,.245-248, 624, 649, 660, 674,
787, 789, 848, f. 246, 674
Distribution 691, 719, m. 246
Root system 649, 652, f. 651
Seed 464, 564, 810, 814, f. 464, 563
Morrow, G. BE. 826
Morse, W. J. 842, 849
Morton, J. 750
Mosquitos harbored by weeds 681
Moss 665, 667
Bear 693
Rose 134
Moth, Diamond-back 677
Ghost 677
Mullein 292,
Otter 677
Mother Cell 616, 867, f. 616
Motherwort 276-277. 777, 788, f. 276
Distribution 720, 1. 277
Seed 470, f. 471
Mouse-ear Chickweed 122, f. 124
Larger 122, 787
Distribution m. 124
sp. 740
Mouse-tail, Distribution 741
Mueller, Ferdinand V. 731, 733, 734
Mugwort, Western 366-367, 790, f. 366
Distribution m. 367

m. 269

724, 756-757

472, 473, 570, 720, 728

895

Muhlenberg, Marsh 35-37, f. 35, 36
Distribution 714, ™m. 36
Seed 414, f. 414
Muhlenbergia mexicana 32-34, 790, f.
Comoe
Chemical composition 34-35
Distribution 715, m. 33
Seed 413-414, f. 414
racemosa 35-37, 790, f. 35, 36
Distribution 715, m. 86
Seed 414, f. 414
Schreberi 30-32, f. 31
Distribution 715
Seed 414, f. 414
sp. f. 676
Muhlenberg’s Smartweed 88-90
Mullbery 605
Mullein 291-292, 310, 777, f. 291
Distribution 687, 720, m. 292
Seed 72, 570, f. 473, 570
Family 291-296
Distribution 725
Seed 472-474, 570
Moth f. 292
Distribution 720, 728
Seed 472, 570, f. 473, 570
Mundy, H. G. 843
Munerati, O. 829, 858
Munn, M. F. 834
Munson, W. M. 843
Murray, D. 747
Musk Hrodium, Distribution 725
Mustard, Ball 163, f. 163
Distribution 717
Seed 814
Black 142, 157-159, 788, f. 158, 542, 605
Distribution 696, 717, 725, m. 158
Seed 445-446, 541-543, 776, 810,
811, 814, f. 445, 542
Family 142-170, 634, 844, 846
Diseases 678, 680
Distribution 724, 733-734
Seed 441-448
Hairy, Seed 544
Hares-ear 161-162, 592, 788
Distribution m. 162
Seed 446, 814, 815, f. 446
Hedge 164-165, 659, 677, 787
Chemical composition 165, f. 169
Distribution 717, 725, m. 165
Seed 446, 543, 544, f. 447
Indian, Seed 446, f. 446

Mildew 678

sp. 657, 660, 692, 709, 725, 773, 826,
847, 848, 850

Tansy 660

Treacle, Distribution 741

Tumble 794
Tumbling 165-167, f. 166, 733
Distribution 717, m. 167
Seed 446, 544, 815, f. 447, 542
White 142, 663, 716
Seed 444, f. Wh
Wild 155-157, Ts iia TENS
Chemical composition 157
Distribution 727, 736, m. 157
Seed 793, 794, 796, 807, 808, 810,
811,
Myagrum 699
Myosotis 664
Myosurus minimus, Distribution 741

Nadelmann, Hugo 545, 585
Naftsger, T. L. 968
Nebraska Flora 845
Seed investigations 833
Weed legislation 794, 806
Weeds 693, 745, 748, 755, 757, 765,
844, 847
Neckiweed syn. Speedwell
Needle Grass 89, 790, f. 666, 667
Neilreich, A. 737, 738, 740, 843
Nelson, A. 81, 188, 826, 837, 844

896

Nelson, A. HE. 844
Nepeta cataria 273-274, 777, f. 274
Chemical composition 273

Distribution 719, m. 273
Root system 654
Seed 469, 566-567, f. 469, 567
hederacea 275-276, f. 279
Distribution 719, m,. 276
Nerve 867
Neslia paniculata 163, f. 163
Distribution 717
Seed 829
Nettle, Day 664
Dead 665, 723, 822
Distribution 719, 723, 727
Family 69-74
Distribution 725
Seeds 424-425, 524-525
Hemp, Distribution 720, 727
Horse 67, 283-284, 285, 786, 794, f.
285, 638, 765
Distribution 705, 720, 765-766, m.
285
Root system 651
‘Seed 471, 568, 637, f. 472,
Sp. 736
Stinging (Urtica dioica) 667
Stinging (U. gracilis) 69-70,
69, 602, 603
Chemical composition 70
Distribution 708, 715, m. 70
Root 652
Seed 425, f. 425
Nevada seed investigations 831
Weeds 757, 842
New Brunswick, Weeds of 750, 762
New England Flora 714
Weeds 709
New Hampshire seed legislation 833
Weeds 748, 845
New Jersey weed legislation 794
Weeds 757, 765, 841
New Mexico, Weeds of 757, 846
New South Wales Flora 7 31 -
Weeds 843
New York
Seed investigations 833-834
Weed legislation 794
Weeds 747, 750, 757, 760. 765
Newberry 766
Newell, W. 757, 760
Newfoundland weeds 754
Newman, C. L. 842
Nicandra physaloides, Distribution 737
Nichols, Mary A, 477, 478, 489, 582
Nicotiana glauca, Distribution 696
Nigger-head sun. Black-eyed Susan
Nimble Will 30-33, f. 31, 83
Distribution 715
Night-flowering Catchfly 130-132, 437,
638, 716, 790, 810, 814
Nightshade, Black 281-283, 625, 630,
ils C20) fa CSL.) 282
Distribution 687, 696, 697, 720, 736,
m. 282
Root system 645
Seed 277, 291, 471-472,
568
Deadly 736
Family 277-291
Distribution 725, 765, 767
Seed 471-472, 568-569
sp. 677, 7388
Spiny, Seed 569, f. 568
Three-flowered, Distribution 738
Nobbe, F’. 827, 830, 850, 858
Nobbs, EB. A. 850
Nodding Chickweed 122-123
Smartweed 86-87
Nodes 651, 867
North America,
740-743
Weeds 696, 731, 732,

568, 688

788, f.

569, f. 472;

Indigenous plants of

733, 734

INDEX

North Carolina met eneal plants 854
Pure Seed Act 83
Seed ere eats 830, 860
North Dakota. See Dakota, North
Northern Fireweed 694, 7038, 726, 741
Nut aeee 63, 64, 696, 697, 715, 741,
Extermination 63
Northwest Territories weed legislation
793
Norton, J. B. S. 833, 844
Norway, Weeds 852
Notchweed f. 594
Nova Scotia, Weeds 756
Noxious Weed Act 793
Noxious weeds 796
Nucellar layer 516, f. 513
Nucellus 619, 867
Nucleus 616, 617
Nut Grass, Northern 63, 790, f. 64
Distribution 696, 697, 715,
m. Gh
Southern 63
Distribution 722, 723
Nuttall, Thos. 374
NYCTAGINACEAE 3, 119-120, 533
Distribution 716, 724
Nyctelea 660

Oak, Distribution 695
Transpiration of 671, 673
Jerusalem, Distribution 716, 746
Oak-leaved Goosetoot, Distribution 746
Oat Grass Seed 810
Bulbous syn. Pearl Grass
Tall, Seed 813
Oats 8, f. 609
Blindness of 677
Distribution 715, 736, m. 41
Reed 415-416, 674, 810, 814, 829,
. 416
Impurities in 155, 674, 692, 829
Side 689
Wild 40-41, 415-416, 664, 665, 679,
Talay WR, TES Wests Sl)
Q’Brine, D. 837
O’Connor, John 750
Oenothera biennis 224, 225, 776, 788,
le) Fj. ep
718, 762,

Distribution 690,
Seed 560, f. 560
grandiflora, Distribution 696
laciniata, Distribution 737
sinuata syn. O. laciniata
sp. 734
Oesterle 538, 553
Offshoot 654
Ohio Flora 723
Seed investigations 831
Weed legislation 794, 807-808
Weeds 747, 758, 757, 766, 825, 842,
843, 845
Oklahoma Flora 838
Weeds 838
Okra 213
Old Witch Grass 12-14, f. 18, 706
Distribution 660, 714, 740, m. 14
Seed 410, 828, f. 410, 676
Oleaster f. 602
OLEACEAE, Distribution 724
Olive, FE. "Ww. 8
Olive Family, Distribution 724
Olson, O. M. XI
Omaha weed legislation 806
ONAGRACEAE 4, 224, 225, 776
Bibliography 586
Distribution 718, 724, 762
Seed 460, 560
Onion 6, 66, "624
Wild 67, 623, 852, f. 68
Distribution m. 68
Seed 814
Ononis spinosa 667

741,

NM. 220

INDEX

Onopordon acanthium 667, 677
Distribution 725, 736
Ontario weed legislation 793
Weeds 747, 841, 842, 843, 858
Oospora scabies 680
Orach 109-110, 789, f. 110
Distribution 716, 740, 746, m. 110
Seed 433, f. 433
Garden, Distribution 736
Silvery, Distribution 746
Orange Hawkweed 502, 712,
842, 846, 849
Orchard Grass, Distribution 715
Seed 417, 810, 811, 813, 828, 832,
857, f. 417
See also Marsh Muhlenberg
Oregon Flora 694
Weed legislation 794
Weeds 747, 750
Organs, Essential 605, f. 605
Origanum 693
Ornamental plants become weeds 712
Orobanche ramosa, Distribution 735
Orobus 693
Orpine Family, Distribution 724
Orr, Ellison 745, 766
Orton, W. A. 833, 849, 857
Osborn, B. EF. 76
Osborne, oO. M. ota
Oscinis frit 677
Osmorrhiza longistylis, Seed 561, f. 561
Ostenfeld, H. C. 753, 766, 844
Osteosclerids 867
Oswald, E. I. 833
Oswald, W. L. 832, 844
Otter Moth 677
Ovule 618, 619-621, 624, 867, f. 620
Ovary 617, HOG If 616, 618, 619
wall as disseminating mechanism 630
OXALIDACEAE 4, 199, 201-203, 634
Distribution 718, 764
Seed 456-457
Gedlis cormiculata 202-203, 787, f. 202,
3

Distribution 696, 697, 734, 741
Family 199, 201-2038, 634
Distribution 724, m. 203
Seed 456, f. 457
Purple- flowered 199
sp. 618, 631, 786
stricta "201-202, f. 201
Distribution m. 202
violacea 689
yellow 199
Root system .645
Ox-eye 338-339, f. 3388
Distribution 720, m. 339
Seed 486, f. 486
Daisy 362-364, 667, 793, 794
Chemical composition 364
Distribution 727, 755, m. 364
Root system 654 :
Seed 492, f. 492, 638
Rough syn. Ox-eye
Ox-tongue, Bristly, Seed 497, f. 498
SE nyctagineus 119-120, 787,
= AL
Distribution 716, m. 120
Seed 533, f. 53)
Oxytropis lamberti 194- 195, f. 195
Distribution m. 195
Seed 454, 552, f. 454, 551
Oyster Plant, Distribution 2B) BS
Seed 497, f. 498
Vegetable syn. Oyster Plant
Ozonium omnivora 680

Pacific Coast weeds 725, 750
Packard, W. EH. 839
Paczoski, J. 829, 844

Page, C. N. 757

750, 814,

897

Paige, F. W. XI, 755, 757, 761, 762, 767
Paint Brush syn. Orange Hawkweed
Painted Cup 702
Distribution 694
Pale Dock 716
Palea f. 609
Palet 867
Palisade Cell see Cell, Palisade
Palmer, Edward 767
Palmer, S. H. 746
Pammel, L. H. 274, 581, 582, 588, 584,
585, 645, 745, 746, 749, 750, 751,
WSs, 5S, WOO OB, WOH, GG aS
774, 801, 823, 824, 825, 826, 834,
835, 837, 844, 850, 851, 854, 858,
861
Pampas Flora 701
Grass 8
Panie Grass, Scribner’s 660, 689
Panicum capillare 12-14, 790, f. 13, 706
Distribution 690, 705, 714, 740, 844
Seed 410, f. 410
dichotomiflorum 14, f. 15
Distribution 714, m. 15
glabrum syn. Digitaria huwmifusa
miliaceum, Seed 411, f. 411
proliferum, Seed 410; f. 410
seribnerianum 688
Sioy abil, byallr/
Distribution 701
virgatum, Seed 410-411, f. 411
Pansy, Common, Distribution 727
Wild, Distribution 722
Panton, J. H. 836, 858
Papaver 539, 633
rhoeas, Distribution 735
somniferum, Seed 440,
440, 587, 5388
PAPAVERACEAE, Distribution 724
Seed 440-441, 536-539
Papilla 617, 868
Pappaphorum, Distribution 701
Pappus 868, f. 64
Papua, Weeds of 733, 734
Papyrus. 63
Parachute as seed carrier 629, 633
Parenchyma 868
Cells see Cell, Parenchyma
Parietal placenta f. 619
Parietaria pennsylvanica 72-74,
in 1, US
Distribution 738, m. 73
Paris quadrifolia, Distribution 693
Parish, E. O. 845
Parish, S. B. 725, 845
Parosela dalea syn. Daiea alopecuroi-
des, f-. 192
Pink 1192) f. 792
Distribution mm. 193
Seed 550-551, f. 5a1
iwehaamn (Cs (Oy We Waly 257
Parrish Cala rcalecog
Parsley f. 612
Family syn.
Fool’s 663
Distribution 736
Parsley-piert 664
Parsnip 224, 788
Seed f. 688
Cow 234, f. 234
Seed 562, f. 561
Water, Distribution 734
Wild 228-230, 794. 796, 807, 808, f. 229
Distribution 688, 719, 1. 230
Root system 648
Seed 461, f. 462
Parsons, C. L. 831, 859
Partridge Pea, Distribution 718
Paspalum platycaule, Distribution 722
sp., Distribution 701
Passiflora foetida 847

536-538, f.

788,

Carrot Family

898
Pastinaca sativa 228-230, 788, 796, f.
229
Distribution 719, 1. 230
Seed f. 688

Pasture Thistle 651
Weeds 838, 845
Patience Dock 763

Patrick, G. E., 826, 837
Pavon, J. 753
Pawpaw 687
Pea 180
Partridge, Distribution 718
Sweet 180
Wild 790

Peach 175, 632
Peach-leaved Dock 78-79
Pear 175, 632
Pearl Grass 664, 665
Pease, A. 845
Peavine Clover, Seed 812
Pedicel 868
Peduncle 864
Pegomyia betae 676
Pelargonium f. 602
Pellitory 72-74, 788, f. 72, 73
Distribution 738, m. 736
Wall f. 597
Pennisetum typhoideum, Seed 813
Pennsylvania seed investigations 831
Smartweed 90-91, 430-431, 645, 657,
658, 659, 660
Weed legislation 794
Weeds 750, 759, 765, 768, 839
Pennycress 143-144, 788, 793
Distribution 692, 699, m. 144
Seed 441, 814, 815, f. 441
Field, Seed 814
Pennyroyal 268
Pepper. Water 92-93, 594, 775, f. 93
Distribution 734
Seed 430, f. 429
Mild 95-97, 594, 788, f. 95
Distribution m. 96
Seed 430, f. 429
Peppergrass, Large 144-145, f. 15
Distribution 717, 728, m. 145
Seed 441-442, 539-540
Small] 146-147, f. 146, 692
Distribution 691, 717, 734, m. 147
Seed 441, 540, f. 442, 541, 638, 688
Southern 723
sp. 660, 785
Diseases 678
Seed 674, 815, f. 676
Virginia syn. Large Peppergrass
Wild sun. Large Peppergrass
Peppermint 268, 709, f. 270
Distribution 720
Percival, John 677, 825, 843
Perennial Ragweed 331-332, 651, 689
Rye Grass 420-421, 789, 811, 813
Sow Thistle 394-396, 499, 663, 753,
793, 808, 814, 819, 826, 842
erent: 648-649, 650, 691, 695, 786,

68

Perfect flowers 605, f. 604
Perianth 6099, 868
Pericarp 516, 868, f. 516
Peridermium pini 678
Perigynium 868
Perigynous flowers f. 610
Perisperm 868
Peronospora effusa 678

parasitica 677, 678
Perrin, C. M. 750
Persicaria sim. Lady’s Thumb
Persimmon 687
Pertinacity of weeds 714
Peru, Weeds of 753
Petal 604, &68
Peter, A. M. 837
Petersen, N. F. §
Peterson, C. H. 762

INDEX

Peterson, Maude G. 854
Petiole 591, 868, f. 591
Petunia grandiflora, Distribution 727
Phacelia sericea, Distribution 695
tanacetifolia, Distribution 738
Pheasant as seed destroyer 629
Phenology of weeds 785-790
Philadelphia Lily 689
Phleum pratense f. 505
Distribution 715
Seed 414-415, 517, f. 414, 505
Phloem 868, f. 598
Phlox drummondii, Seed 829
Phorbia brassicae 677
Photosynthesis 516, 599-600, 868
Phragmites communis, Distribution
T3Sy WAC
Phyllotreta nemorum 676
Physalis heterophylla 279, f. 280
lanceolata 279-280, f. 280
Distribution m™. 280
pubescens, Seed 569, f. 568
sp. 651, f. 623
subglabrata 279, 789
virginiana 279, 281
Distribution m. 281
Phytolacca decandra 776
Distribution 705, 763
PHYTOLACCACEAE 3. 776
Bibliography 586
Distribution 763
Pickerel Weed, Distribution 712
Picris echiodes, Seed 497, f. 498
Pieper, H. 828
Pie-plant 74
Pierce, R. E. 749
Pieters, A. J. 583, 835, 859
Pigeon Grass 17-20, f. 18
Chemical composition 19
Distribution 714, 732, mv. 19
in cornfields 17
Seed 22, 413, 640, 814, f. 413, 676
Pigweed
(Amaranthus) 113-115, 645, f. 114, 595
Chemical composition 115

Distribution 716, 723, 734, 737,
m. 115
Seed 434, f. 435. 636. 676
(Chenopodium) 67, 107-109, 664, f.

108, 217
Chemical composition 109
Distribution m. 109
Family 113-119
Seed 434-435 (See Amaranth)
Green (A. retroflexus) syn. Pigweed
Prostrate 117-118. 788, f. 117
Distribution 716, m. 117
Seed 434, f. 434
Rough syn. Tumbling Pigweed
Russian, Seed 814
sp. 657, 687, 723, 786, 834
Spreading syn. Prostrate Pigweed
Tumbling 115-116, 790, f. 11/6
Distribution 716, m. 116
Seed 434, f. 435, 638
Winged 99-101, 788, f. 100, 101
Distribution 693, 716, m. 100
Seed 451, 740, 746, f. 431, 730
Pilose Eragrostis sun. Spear Grass
Pimpernel, Distribution 719, 740
Pine 3, 6
Cluster-cup 678
Lodge-pole. Distribution 694, 695
White 6
Pink f. 606
Dalea 454
Family 120-134. 435-438, 533-536
Distribution 724
Garden 120
Parosela 192-193
Smartweed 86-87,
Pineapple Weed, Distribution 725, 729
Pinus murrayana, Distribution 694

430, 742

INDEX 899

Pistil 604, 616, 617-620, 868

Compound 619, f. 619

Pistillate flowers 605, 7. 606, 607
Pitchforks syn. Beggar-ticks
Placenta 618, 868

Axillary f. 619
Central f. 619
RPanietal” fj. 619

PLANTAGINACEAE 296-307

Bibliography 586
Distribution 721, 762-763
Seed 474-476, 571-572

Plantago arenaria, Distribution 726

aristata 304-307, f. 306
Distribution 720, 740, m. 307
Seed 474, 572, 810, f. 474, 572
coronopus, Distribution 736
lanceolata. 301-303, 787, 796, f. 302
Chemical composition 303
Distribution 696, 697, 698, 720,
736, 762, 17. 302
Root system 654, f. 648
Seed 475, 572, 810, f. 475, 571
major 297-299, 664, Ff. 298, 299
Chemical composition 299
Distribution 696, 698, 720, 736,
742, m. 299
Seed 475, 572, f. 475, 572
maritima, Distribution 736
media, Distribution 736
purshii 303-305, 787, f. 304
Distribution m. 305
rugelii 299-301, 788, f. 300
Distribution 720, m. 301
Seed 475, f. 475, 676
sp. 778
Plantain, Bracted 305-307, 740, f. 306
Distribution 720, m. 3807
Seed 474, 571, 572, 810, 814, f. 474,
o72
Buck syn. Buckhorn
Common 297,299, 664, f. 298, 299
Chemical composition 299, 720, 742
Distribution 696, 698, 720, 742, m.

299
Seed sao oneleu merlot
Dooryard syn. Common Plantain
Family 296-307
Distribution 724, 735, 762-763
Seed 474-476, 571-572
Indian, Seed 493, f. 493
Prairie 303-305, f. 304
Distribution m. 305

Pursh’s 787

Rat-tail, Seed f. 638
Ribbed syn. Buckhorn
Rugel’s 299-301, 788, f. 300
Distribution 720, m. 301
Seed 475, 814, f. 476, 676
sp. 637, 665, 667, 677, 708, 710, 736,
778, 785, f. 623
Root system 645
Plants, Dioecious 605
Monoecious 605
Polygamous 605
Plasmodiophora brassicae 677, 680
Plasticity of plants 706-707
Plum 175, 687
Plutella maculipennis 677
Plymouth Flora 845
Poa annua 664, 677, f. 598
Distribution 715, 725
arachnifera, Seed f. 639
compressa, Distribution 715
Seed 418, 811, 812, f. 418, 639
Impurities of f. 639
nemoralis, Seed f. 639
pratensis f. 598
Distribution 715
Seed 418, 811, 812, f. 418, 639
sp. 693 :

trivialis, Distribution 715
Seed f. 639

Pod 868
Poinsettia 205
Poison Darnel 52-53, 520, 522-524, 692,

69165) 16995) U5
Hem eck 709, 710, 719, 728, 768-769,

Ivy 213, 214, 215, 652, 683, 787, 843

Poisonous weeds 52, 53, 66, 67, 194,

195, 218, 214, 215, 652, 683, 709,
710, 715, 719, 728, 768-769, 776,
787, 838, 847, 848, 852, 858, 854

Pokeweed 776

Distribution 763

Polanisia graveolens 171-172, f. 172

Distribution 717, m. 172
trachysperma 171, 788, f. 173

Pollen 615-617, 869

causes disease 681
grains 616, 617

mother cells 616, f. 615
sacs 616, f. 616

Pollination 616, 869
Polygamous plants 606
POLYGONACEAE 3, 74-99, 633

Bibliography 586
Distribution 715, 724, 763
Seed 425-431, 525-532

Polygonum acre 97, f. 96

Distribution 716
Seed 428, f. 428
aviculare 84-85, 663, 788, f. 84
Distribution 716, 736, 742, m. 84
Seed 428, 429, 431, 663, 677
convolvulus 97-99, 789, f. 98
Distribution 696, 698, 716; 829, m.

99
Seed 429, 528-531, f. 429, 526, 528,
529, 530, 581, 536, 729
dumetorum y. scandens 527
erectum 82-83, 789, f. 83
Distribution 696, 716, 725, m. 83
Seed 429, 527, f. 429, 526
hydropiper 92-93, 594, 775, 789, f. 98
Distribution 734, 742
Seed 430, 527, f. 429, 526
hydropiperoides 95-97, 594, 788, f. 95
Distribution m. 96 ?
Seed 430, f. 429
lapathifolium 86-87, 788, f. 87
Distribution 716, 734, 742, m. 87
Seed 430, f. 430
muhlenbergii 88-90, 789, f. 88, 89
Distribution 716, m. 88
Root system 652
Seed f. 431
orientale, Distribution 763
Seed 428, f. 428
pennsylvanicum 90-92, 594, 660, 664,
3S Tio BE 2
Seed 430, f. 430
persicaria 92, 938-95, 665, 788, f. 94
Chemieal composition 673, 674
Distribution 691, 716, 736, m. 95
Seed 430, 527, f. 430, 526, 676
ramosissimum 85-86, 789, f. 86
Distribution m. 86
Seed 431, f. 431
sp. 691, 785
virginianum 527

Polytrichum commune, Distribution 693
Popenoe, E. A. 766
Poplar 605

Distribution 695

Poppy 663, 665, f. 623

Seed 440, 536-538, f. 440, 587, 538
Corn f. 618
Family, Distribution 724
Mexican, Distribution 696, 839

900

Prickly 440-441, f. 440
Distribution 729
Seed 539, f. 539
Rocky Mountain syn. Prickly Poppy
Populus grandidentata 703
tremuloides 703
* Porcher, F. P. 854
Porcupine Grass syn. Needle Grass
Pore-canal 869
Portulaca oleracea 136-138, 788, f. 137,
764
Chemical composition 138
Distribution 691, 696, 697, 701, 717,
723, 729, 763-764, m. 138
Seed 438, f. 438
sp. 701
PORTULACACEAE 3, 134-138
Distribution 717, 724, 763-764
Seed 438
Potato 67, 277, 283
Family syn. Nightshade Family
Scab 680
Sweet 241
Potentilla anserina 177-178, 663, 787,

fia Bie
Seed 448, f. 448
canadensis, Seed 448-449, f. 449
fruiticosa 632
monspeliensis 175-176, Dap 789, f. 449
Distribution 742, m.
monspeliensis v. oonen 614
seed 449, f. 449
Poverty Grass 28-29, 790, f. 28
Distribution m. 29
Long-awned 29-30, f. 30
Poverty Weed syn. Marsh Hider
Prairie Clover, Hairy 550, 551, 552
Farmer 247, 382, 826
Iowa, Native Flora of 688-692
Larkspur 142, 439
Plantain 303-305
Rose, Wild 178-180, 449, 450
Sunflower 342-343, 487, 488
Thistle 376-377, 789, 790
Prenanthes alba 501, f. 501
sp. 703
Prentiss, A. M. 845
756

Preston, E. H.
Prickles 869
Prickly Lettuce 396, 397, 398, 399, 500,
501, 596, 645, 664, 721, 725, 729,
747, 758, 789, 819, 826, 838, 840
ee ee) 396-399, 500, 501, 721,

Poppy 440, 441, 539, 729
Sida 218, 219, 559, 560, 718, 722, 723,
734, 789
Primrose, Evening 224-225, TETUD.
788, 819, f. 225
Distribution 718, 762,
Root system 645
Seed 460, 560, f. 560
Evening (O. grandiflora), Distribu-
tion 696
(O. sinuata), Distribution 737
Family 224-225
Distribution 724
Seed 460, 560
PRIMULACEAR, Distribution 719, 724
Prince’s Feather 74
Distribution 763
Seed 428, f. 428
Prister 583
Privet f. 594
Procambium 869
Propagation of weeds 650-651
EROnerty tax for weed destruction 800,
Prostrate Pigweed 117-118
Spurge 208-209
Vervain 267-268, 690
Protein 869

592,
Mm. 225

INDEX

Prunella vulgaris 270-271, 667, 777, f.
271

Distribution 142, m. 271
Seed 470, f. 471, 638
Prunus emarginata, Distribution 694
pennsylvanica 703
serotina f. 637
Psedera quinquefolia 213
Pseudotsuga taxifolia, Distribution 694
Prussian weeds 754
PTERIDOPHYTA 3, 5-6
Pteris, Distribution 693
aquilina 667, f. 694
Distribution 693
caudata, Distribution 693
sp. 693
Puccinia coronata f. 629
graminis 678, 680, f. 679
hieracii 678
pringsheimiana 67
rubigo-vera 680, ie 678, 679
Puccoon, Narrow-leaved, Seed 467, f.
467
Puget Sound Weeds 727
Pulse Family 180-199, 450-455, 545-554,
592, 734
Distribution 724, 759-761
Purity of Seeds, Standard 812-813
Purple Cockle 814
Cone-flower f. 666
Loco-weed 194-195
Thorn Apple syn, Jimson Weed
Stramonium syn. Jimson Weed
Purslane 136-138, 788, f. 137, 764
Chemical composition 138
Distribution 691, 696, 697, 701,
717, 723, 729, 763-764, m. 138
Seed 438, 814
Family 134-138
Distribution 724, 763-764
Milk syn. Creeping Spurge
Pusley syn. Purslane
Pyrethrum 307
Pyrola, sp. 702

Quack Grass 8, 27, 53-58, 241, 273, 664,
665, 688, 773, 774, 781, 786, 794,
796, 810, 819, 822, 844, 847, 848,
850, 852
Chemical composition 57-58
Diseases 680, 736
Distribution 715, 736, m. 59
ergot 680
Root system 648, 651, f. 643
Seed 421-423, 640, 674, 810, 814, f.
422, 688
Quade, BCs 1B) DIE
Quaking Grass 667
Quassia Family, Distribution 725
Quebec weed legislation 793
Weeds 768
Queensland Weeds 838
Quick Grass sun. Quack Grass
Quince 175, 632

Raceme 611, 869, f. 612
Rachilla 869
Rachis 869
Raddin 765, 766
Radial leaves 592
Distribution 717, mv. 269
Radicula armoracia 168-169, 788, f. 169
Distribution 717, m. 269 i
nasturtium-aquaticum, Distribution
717
palustris 167-168, f. 167
Distribution 742, 1. 168
Seed 447, f. 447
Radish 142, 788
Cystopus on 678
Seed 444, f. 444
White 845
Wild syn. Jointed Charlock

INDEX ; 901

Rafinesque, C. S. 774, 854
Ragweed, Greater 326-327, 789, f. 3827,
671, 691
Distribution OO 7205
Root system 645
Seed 484, 574, 674, 814, f. 483
Lance- leaved, Seed 483, f. 483
Large syn. Greater Ragweed
Perennial 331-332, f. 832
Distribution 689
Root system 651
“Seed 484, f. 483
Pollen 681
Smaller 328-331, 657, 658, 659, 660,
778, 789, f. 329, 330
Distribution 698, 705, 720, 730, 740,
mr. 330
Root system 645
Seed 482-483, f. 483, 557
sp.. 625, 793, 807, 822
Western Syn. Perennial Ragweed
Ragwort 665, 667, 678, 743, 750
RANUNCULACKEAB 4, 139-142
Bibliography 586
Distribution 717, 724
Seed 438-440, 536
Ranunculus abortivus 139-140, 787, f.
139
Distribution 717, m. 140
Seed 440, 536, f. 440, 586
aecris, Distribution 717
Seed 440, f. 440
arvensis 663
Distribution 736
bulbous, Distribution 717
eymbalaria, Distribution 742
flammula, Distribution 736
multifidus, Embryo f. 621
pennsylvanicus, Distribution 742
repens, Distribution 742
septentrionalis 140-141, 787, f. 141
Distribution 717, 736, m. 141
Rape 142
Seed 445, 810, 811, 813, f. 445
Broom 665, 735, 827
aaa raphanistrum 153-155, 665,
5.

mM. 827

Chemical composition 674
Distribution 696, 699, 717, 735, 736,
Mm. 155
sativus 788
Distribution 725
Seed 444, f. 44
Raphe 869
Raspberry 175, 703
Black 632
Rat-tail Plantain 638
Rattle, Yellow 667
Distribution 742
Rattle-box (Astragalus) 193-194, f. 194
Bee a (Crotalaria) 182- 183, 788,
182
Distribution 718, m. 183
Seed 450, 545-546, f. 450, 546
Rattlesnake Root, Seed 501, f. 501
Weed 703
Ratzeburg, J. T. C. 754, 767, 826, 845
Rawson, W. B. 851
Raymond, L. H. 749
Receptacle 869
as seed disseminator 631
Red Bud 180
Campion 605, 716
Cedar 6
Cherry 694
Clover 78, 130, 149, 175, 360, 451,
674, 692, 698, 705, 712, 726, 810,
Siler Sihoe 828. 830, 831, 832 833.
835, 836, 855, 856, 857, 858, 859,
Mammoth 811, 812
Medium 811, 830

Small 812
Top 415, 680, 715, 805, 806, 810
Red River Valley Weeds 751
Redroot 113-115, f. 116
Chemical composition 115
Distribution m. 115
Red-seeded Dandelion 390-391,
63805 V2!
Red-shank syn. Lady’s Thumb
Red-veined Dock syn. Bitter Dock
Reed Grass, Distribution 733, 736
Reed Bent Grass 693, 736
Reed-mace Fungus 677
Rees, Bertha 829
Register and Leader 803
Rehnstron, EH. 750
Reinbott, ©. 746
Reppert, F. 745, 749, 760, 763
Reseda lutea, Distribution ply
RESEDACEAE, Distribution 717, 724
Respiration 600, 869
Rest-harrow 607
Reum, J. A. 845
Reynold, A. P. 749
RHAMNACEAE, Distribution 724
Rhinanthus erista-galli major,
bution 736, 74
erista-galli minor, ae eabution 736
Rhizoctinia violacea 677
Rhizome. 649, 650, 651, 869, f. 643, 651,

Rhode Pana Weeds 766
Rhodin, S. 851
Rhomb-leaf Sida 723
Rhus glabra 841
toxicodendron 213, 214, 787, f. 214, 215
Root system 652
Rib 869
Rib Grass syn. Buckhorn
Ribbon Grass 8
Ribwort 665 :
Rice Cut Grass f. 739
Distribution 740
Rice weeds 840, 847
Wild, Seed 856 ‘
Richardia scabra, Distribution 723
Richman, Mrs. 766
Ricinus communis, Distribution 696,
697, f. 697
Ridley, H. N. 859
Road funds, How applied in Iowa 800
Roberts, B. D. 762°
Roberts, H. F. 831, 859
Robinia pseudo-acacia,

Rocket 159, 160, f. 159
Distribution m. 160
Yellow 787
Robinson, B. L. 731, 754, 767, 768
Rocky Mountain Bee-plant 173-175, 448
Sand bur 794

498,

Distri-

Distribution

Weeds 729
Rolfs, P. Hl. 557, 586, 745, 748, 751,
755, 756, 859

Rollins, J. 766
Romer, F. 845
Rommatin 852
Root 869
Aerial 645
Annual 647, 649
Winter 647, 657
Biennial 648, 649, 650
Central 644
Classification 647, 649
Fibrous 645, 650, f. 649
Fleshy 648, 650
Forms 644-650
Functions 644, 645
Lateral 644
Parasitic 645
Perennial 648-649, 650
Primary 644, 650
Multiple 644

902

Reserve food 645
System 643-650
Noxious weeds, Table 645
Tuberous 645
Vertical 651
Root-rot, New Zealand 678
White 678
Root-stock 650, 869
Root weeds 736
Roots of weeds 643- 650, 861
Rosa arkansana syn. of pratincola 178-
180, 632, f2 178; 279
Distribution TANG Tite LE)
Root 652
Seed 450, f. 449
ROSACEAE 4, 175-180
Distribution 717, 724

Seed 448-450, 545
Rose, J. N. 825
Rose
ene 175-180, 448, 450, 545, 592.
Distribution 724, 734
Moss 134

Prairie syn. Wild Rose
Sie 8, (Oy Oia 1S; Ol, GOH
Wild 178-180, 632, f. 178, 179
Distribution rare m. 179
Root 652
Seed 450, f. 449
Rosellinia necatrix 677
radiciperda 678
Rosenberg 754
Rosenthaler 583
Roster 766 :
Rothamsted, Experiment Station 664
Rothrock 767
Rotminstror 643
Rough Ox-eye syn. Ox-Eye
Pigweed syn. Tumbling Pigweed
Rough-stalked Meadow Grass 639, 715
Rousseau, H. 843
Roussille 851
Roger, C. B. 766
Rubber shoes, Weeds distributed by
710-711
Rubber plants 234
RUBIACEAE 572-573
Distribution 724
Seed 476

Rubus nutkanus, Distribution 693

ursinus, Distribution 6938
Rudbeckia hirta 339-340, 689, 787, f.
83
Distribution 705, 737, m. 339

laciniata, Distribution 737
Seed 486, f. 486
Rue, Meadow, Seed 438, f. 439
ates eee ci 299- 301, 475-476, 720,
TR oH, ILy. 753
Rumex acetosa 667
Seed 526
acetosella 667, 774, 787, 819
Distribution 696, 697, 716, 735, 736
Root system 651

Seed 810

altissimus 787, 796
Distribution 716
Root 654

Seed 810
erispus 74-76, 774, 7
Chemieal composition
Distribution 697, 7
io
Root system f.
Seed 426, 427,
obtusifolius 78, 79, 5
Distribution m. 79
Seed 427. f. 427, 726
patientia, Distribution 763

INDEX

sanguineus, Distribution 716
sp. 663, 676
Rumler-Breslau, Dr. 851
Runch 664, 665
Runge 753
Runner 869
Rush Family 63-65, 623
Grass, Sheathed 37-38, 790, f. 87
Distribution 715, m. 88
Small 38-39, 790, f. 39
Distribution 715, m. 89
Slender 65, f. 65
Distribution 715, m. 65
Spike, Seed 407-408
Rushlike Lygodesmia 403-404
Russian Pigweed 814
Thistle 67, 433, 532-533, 631, 699,
716, 727, 728, 729, 730, 7438-747,
789, 794, 796, 805, 807, 808, 814,
825-826, 834, 837, 839, 841, 842,
845, 846, 847, 848, 861
Tumbleweed syn. Thistle
Weeds 757, 829, 8438, 844
Rust, Cereal f. 679
Chrysanthemum 678
Wheat 678
White 677, f. 681
Rutledge, F. T. 766
Rydberg, P. A. 747, 755
Rye 6, 8
Ergot 678
Grass 785, 789
Seed 810
English syn.
Italian 787
Seed 421, 811, 813, f. 427
Perennial 789
Seed 420, 813
Wild 680
Seed 813
Impurities 829

Perennial Rye Grass

Saffron. Meadow, Distribution 736
Sage, Blue 277, 279, f. 278
Distribution 759, m. 27.
Lance-leaved syn. Blue Sage
Searlet 268
Wood 272-273, f. 273
Distribution mm. 273
St. John’s-wort 223- 7
Distribution 708, m. 224
Family 221, 223-224
Distribution 724
Saint-Quentin 852
Sale 766
SALICACEAE, Distribution 724
Salsify, Seed 497, f. 198
Meadow 497, f. 498
Salsola kali 677, 808
Salsola Kali v. tenuifolia 111-113, 789,
iO Goeaps: elite
Chemical comovosition 113
Distribution 699, 716, 727,
743-746, m. i112
Seed 4338, 532-533, f.
Saltbush 99
Saltwort 677

728, 729,
438, 583, 730

Salvia lanceaefclia_ 277, f. 278, 279
Distribution 759, m. 279
Samek, J. 828, 859

Sample, A. F. 761
Sandbur 25-26, 637, 790,
Distribution 714, m.

Seed 412, 517, f 4/2

Rocky Mountain 794

Sanderson, Mrs. 766

Sandor, C. 851

Sandy soils, Weeds of 819

SAPINDACEAE Bibliography 586

Sapling Clover, Seed 812

Saponaria officinalis 134, 136, 790, f.

1385, 136
Distribution 712, 717, m. 136

INDEX

Seed 533-534, f. 535
vaccaria 132- 134, SO iets
Spurn 696, 697, 717, 728, m.

134
Seed 438, f. 438
Saskatchewan weed legislation 793
Satureja nepeta, Distribution 720
vulgaris
Distribution 720
Saunders, Wm. 836
Saururus, Distribution 693
Saw-toothed Sunflower syn. Meadow
Sunflower
SAXIFRAGACEAE, Distribution 724
Saxifrage Family, Distribution 724
Saxony, weeds 845
Sayre, L. BE. 837, 845
Scabiosa australis, Distribution 839
Seale 869
Scaly Grindelia syn. Guinweed
Scandix pecten-veneris 663
Distribution 736
Seape 870
Searlet Sage 268
Scentless Chamomile 638
Scherer 699, 713, 740, 766
Schips, K. 547, 585
Schively, A. FE. 585
Schleiden, M. J. 585
Schoepf, M. D. 733, 854
School of Instruction 800
Schorler, B. 766, 845
Schreiber, EH. C. 767
Schroder 583
Schréter, C. 852
Schultz, G. 845
Schwabia, Weeds 848
Schwere 583
Sclerenchyma 870
Cell, see Cell, Sclerenchyma
Sclerotic cell f. 574
Sclerotinia 680
sclerotiorum 677
Sclerotium Disease 677
Scotch Thistle 806
Scribner’s Panic Grass 660, 689
Scrophularia leporella 294
marilandica 294-295, 789, f. 295
Distribution m. 295
SCROPHULARIACEAE 4, 291-296, 777
Bibliography 586
Distribution 725
Seed 472-474, 570
Scutch Grass syn. Quack Grass
Secale cerale, Seed 813
Sedge 407, 630, 788, f. 603
Family 63, 407- 408, 623, 636, 678
Distribution 624
sp., Seeds f. 407
Sedum stenopetalum
Distribution 695
telephium
Distribution 712
Seed coat as a factor in germination
829, 856
as weed disseminator 631
Control Stations 856
Development 624
General characters of 407-502
Investigations
Arizona 834
Australia 837
Canada §36-837
Connecticut 830
Denmark 828
Hamburg 827-828
Iowa 834-835
Kansas 831-832
Kentucky 832
Maine 832

903

Maryland 835
Massachusetts 833
Michigan 830-831
Minnesota 832
Nebraska 833
Nevada 831
New Hampshire 833
New York 833-834
North Carolina 830, 832, 860
North Dakota 834
Ohio 831
Pennsylvania 831
Texas 834
Tharandt 827
United States Department of Agri
culture 835-836
Vermont 833, 857
Wisconsin 834
Zurich 828
Laboratory XII
Legislation
Canada 808, 814
Towa 809-814
Maine 809, 814, 860
Michigan 814
North Carolina 832
North Dakota 814
Washington 809
Wisconsin 809, 814
Wyoming 809
Production 615-624
Testing 828, 830, 831, 832, 833, 834,
835, 836, 855, 856, 857, 858, 859,
60
Weeds 736
Seeds, Adulterated 811-815, 827,
857, 858, 859, 860
Agricultural 810
Destroyed by birds 629, f. 636
Germination 24, 99, 829, 830, 831,
832, 833, 834, 835, 836, 837, 855,
856, 857, 858, 859
Microscopie structure of 505-587
Purity of, See Seed-testing
Seattered by birds 629, f. 637, 638
Viability, Standard 812-813
Vitality 821, 828, 829, 830, 831, 832,
833, 835, 836, 837, 855, 856, 857,
858, 859
Weeds 855-60
Self-heal 270-271, 660, 665, 667, 777, f.
271
Distribution 742, m. 271
Seed 470, f. 471
Seidler, L. 673, 837
Selby, A. D. 825, 826, 831, 845, 851, 859
Sempolowski, A. 553, 581
Senebiera pinnatifida, Distribution 723
Senecio canus, Distribution 694
jacobaea 667
Distribution 750
palustris, Distribution 743
sp. 678, 693, f. 623
_triangularis, Distribution 694
vernalis, Distribution 735-754
vulgaris, Distribution 725, 736
Seed 493, 663, f. 493
Senna 180
Distribution 723
Low, Distribution 723
Sepal 604, 870
Setaria glauca 17-20, 789, f.
Chemical composition 19
Distribution 691, 714, 722, m. 19
Seed 22, 413, 511, 512, f. 413, 676
italica, Seed f. 413
panis, Seed 510, 511
sp. 517, 664
verticillata 22-24, 790, f. 23
Distribution 696, 714, UBe, Tile PS

856,

18, 22

904

viridis 20-22, 506, 511, 790, f. 22, 507,
509, 510, 665
Chemical composition 21-22
Distribution 691, 714, 729, 731, m.

22
Seed 412-413, f. 412, 511, 512, 676
Seton, R. S. 851
Settegast 828, 859
Severance, G. 861
Shamel, A. B. 857
Shaw, A. B. 748
Shaw, Thomas 371, 822, 851
Sheath 870
Sheathed Rush Grass 37-38, 715, 790
Sheep pone 80-82, 667, 774, 787, 819,
OL
Chemical composition 82
Distribution 696, 716, 736, m. 82
Root system 651
Seed 425-426, 640, 810, 814, f. 426
Sheep’s Burr 849
Fescue 715
Sheldon, Parley 745
Shepherd’s Purse 151-153, 604, 659, 660,
(HGS, (OM. NMG, WSR5 GD, Ge te Ge
Disease 680, f. 681
Distribution 696, 708, 717, 734,
740, m. 653
Root system 648
Seed 4438, 540-541, 815, f. 443, 542,

638
Sheepweed syn. Stinkweed
Shimek, B. V. XI

Shoo-fly 221-222, 796, 822, f. 222, 761
Distribution 688, 696, 697, 710,
(L2, 713, 718, (61, 762; 794
Seed 460, f. 459
Shoe-string 8§&
Devil's 88
Showy Milkweed 237-238, 719, 787
Shrub 870
Shrubby Cinquefoil 842
Shull, C. A. 861
Siberian Weeds 757
Sicyos angulata 593, f. 594
Distribution 737
Sida, Prickly 218-219, 789, f. 218
Distribution 718, 722, 723, 734, m.
219
Seed 560
rhombifolia, Distribution 698, 723
Rhomb-leaf, Distribution 698, 723
spinosa 218-219, 789, f. 218
Distribution 718, 722, 7238, 734, 740,
m. 219
Seed 560, f. 559
Side Oats 689
Silene antirrhina 788
Distribution 716
Seed 534-535, f. 535
dichotoma 128-130, f. 129
Distribution 712, m. 130
Seed 436, f. 437
gallica, Distribution 725
inflata, Seed 535
latifolia, Distribution 716
Seed 436, f. 4386
noctiflora 130-132, 790, f. 131
Distribution 712, 716, m. 132
Seed 437, 810, f. 437
vespertina, Seed 437, f. 487
virginica, Seed 535, f. 435
Silesia, Weeds of 754
Silky Bent Grass 639,
Cinquefoil 734
Sophora 551
Silphium perfoliatum 482, f. 483
Silverweed 177-178, 663, 665, 787, f. 177
Distribution 742, m. 177
Silvery Cinquefoil syn. Silverweed
Orach 746

Seed f. 639

INDEX

Silybum marianum 701
Distribution 725
SIMARUBACEAE, Distribution 725
Simpson’s Honey Plant 291, 294-295,
789, f. 295
Distribution m. 295
Sinapis arvensis syn. Brassica arvensis
Sinus 870
Sirrine, Emma 525, 586
Sirrine, AS 159. oo
Sisal substitute 216
Sisymbrium altissimum 165-167, f. 166,
733
Distribution 717, 734, 789, m. 167
Seed 446, 544, I 5 5y2
canescens, ‘Seed 54
officinale 164-165, Gee 787, f. 164
Distribution 717, 725, 734, m. 165
Seed 446, 534, 544, f. 447
Sium latifolium
Distribution 734
Skeleton Weed syn. Lygodesmia
Skunk-tail Grass syn. Squirrel-tail
Grass
Skunkweed 708
Sleepy Catchfly 716, 788
Slender Catchfly 534-535
Foxtail 665
Rush 65, 715
Wheat Grass 53, 57, 422, 423
Small, A. J. XII
Small Beggar-ticks 489, 720
Bindweed syn. European Bindweed
Peppergrass 146-147, 441-442, 540,
541, 638, 688, 692, 717, 734
Ragweed syn. Smaller Ragweed
Red Clover 812
Rush Grass 38, 39, 715, 790
Squirrel-tail Grass 787
Stick-tight 489
Small-flowered Buttercup 787
Catchfly 725
Crowfoot 139-140, 446, 536, 717
Dandelion syn. Red-seeded Dandelion
Mallow 725. :
Small-fruited False Flax 638
Smaller Ragweed 328-331, 482-483, 645,
657, 658, 659, 705, 720, 789
Smartweed 95-97, 822, f. 24
Common f. 93
Family 74-99
Seeds 425-431
Marsh syn. Tanweed
Muhlenberg’s syn. Tanweed
Nodding syn. Pink Smartweed

Pennylvania 90-92, 594, 657, 658,
659, 660, 664, f. 91, 92
Distribution 716, m. 91
Root system 645
Seed 430. f. 430
Pinks 865 SS, euScenaesd
Distribution 716, 734, 742, m. 87

Seed 430, f. 430

Slender syn. Pink Smartweed
sp. 687, 691, 788, f. 661
Water 97, f. 96

Distribution 716
Seed 428, f. 428
Smith, J. MH. 756
Smith, Rantste4)
Smith, P. H. 833, 851, 859
Smith, W. G. 845
Smoke Tree 213
Smooth Brome Grass syn.

Brome Grass
Crab Grass 10-12, 408-409, 505, 714,
787, 794, 796,

Hungarian
789, 810
Dock 76-78, 427, 654,

799
Goldenrod 315-316, 480
Snake-bites, Antidote 778

INDEX

pnalkcraot, White 312-313, 780, 789, f.

Distribution m. 313
Seed 477, f. 478
Snapdragon 291
+ Also see Toadflax
Sneezeweed 354-356, 780, 790, f. 355, 356
Distribution 721, m. 355
Seed 490, f. 491
Narrow f. 721
Distribution 722
Snow, Seed Scattered by 629, 687
Snow-on-the-mountain 205, 210-211,
787, f. 210, 712
Distribution 712, 757, m. 211
Seed 458, f. 458
Snowball f. 595
Snyder, Harry 115, 157, ee 273
Soapwort syn. Bouncing Be
Soft Chess 46-48, 419, 715, 733, 789
Grass, Creeping 665, 667
Woolly 665
Maple 634
Soil affected by weeds 681-682, 860
SOLANACEAE 4, 277-291, 777
Bibliography 586
Distribution 725, 756-767
Seeds 471-472, 568-569
Solanum carolinense 283-284, 777, 787,

» fe. eoo)
Distribution 705, 720, 765-766, m.
285
Root system 651
Seed 471, 568, f. 472, 568
heterodoxum, Distribution 738
nigrum 281-283, 625, 777, 790, f. 281,

2
Distnibubion 696, 697, 720, 736, m.

Seo 471, 569, f. 472, 569 -
rostratum 384, 286- 288, 787, f. 286
Distribution 720, 722, 738, 766-767,
844, m. 286
Seed 471, 569, f. 472, 568, 635
triflorum, Distribution 738
Solidago
canadensis 313-314, 790, f. 314
Distribution 690, 721, 737, m. 314
Seed 479, f. 480
lanceolata, Distribution 737
missouriensis, Distribution 689
odora, Distribution 689
rigida 816-317, 689, 790, & weet 633, 738
Distribution 689, m.
Seed 480, f. 480
serotina 315- 316, 790, f. 315
Distribution 738, m, 316
Seed 480, f. 480
Solitary flowers 611, f. 611
Solomon’s Seal, Rhizome f. 652
Somerville, Prof, 851
Sonchus arvensis 394-396, 663,
808, 819, f. 395
Distribution 736, 7538, m. 395
Seed 499, f. 499
asper 393- 394, f. 393
Distribution 721, 736, m. 394
Seed 499, f. 499
oleraceus 391-393, 787, f. 392
Chemical composition 674
Distribution 696, 736, m. 393
Seed 500, f. 499
palustre, Distribution 736
sp. 676
Sophora sericea f. 551
Silky f._551
Sorauer, P. 820, 846
Sorghum, Seed 813
Sorghum halepense 7, 8, f. 7, 722
Distribution 722, 732, m. 7
Seed 408, f. 408

58

790,

905

Sorrel, Field 202-203, f. 202
Distribution 734, 741, m. 203
Seed f. 630
Yellow, 201-202, f. 201
Distribution mm. 202
Horse syn. Sheep Sorrel
Lady’s 659, 787
Distribution 696, 697, 718
Seed 456, f. 457
Ss SO: -82, 540, 667, 774, 787, 819,
8
Chemical composition 82
Distribution 696, 716, 735, 736, m.
&2
Root 651 :
Seed 425-426, 640, 810, 814, f. 426
sp. 678, 833,. f. 594, 638
Also see Sour Clover
Violet Wood 689
Yellow-flowered syn. Field Sorrel
Sour Dock syn. Curled Dock
South America, Weeds of 696, 713, 726,
731, 732, 733, 734
Southern Nut Grass 63, 722, 723 .
Peppergrass 723
pbeay Grass 45-46, 416, 517, 715, 732,

Sow Thistle 393-394, 661, 665, 577, f.
93

Distribution 708, m. 394
Seed 499, f. 499
Annual 391-393, 787, f. 392
Chemical composition 674
Distribution 725, m. 393
Seed 500; f. 499
Field syn. Perennial Sow Thistle
Perennial 394-396, 663, 793, 808, 819,
826, f. 395
Distribution 753, a m. 895
Seed 499, 814, . 499
sp. 736
Spiny, Seed 499, f. 499
Soybean 180
Spacht 768
Spanish Dagger 645
Needle syn. Bootjack
Sparrow, E. E. 767
Sparrows as seed destroyers 629
Spear Grass, Low 664
Distribution 715
Southern 45-46, f. 45
Distribution 715, 732, 740, m. 46
Seed 417, f. 416 -
Spearmint 268
Distribution 720
Specific ero of seeds 828
Speedwell 664
Corn, Distribution 723
Purslane, 296, 297, f. 296
Distribution 720, 728, 740, m. 297
Seed 473, f. 474
Spergula arvensis,
tion 674
Distribution 723

sp. 853 f
SPERMATOPHYTA 3, 6-404
Spike 611, 870
Spike Rush, Seed 407-408
Spikelet 870
Spillman, W. J. 846, 852
Spinach 99, Disease 678
Distribution 712, 125
Seed 432, f. 432, 730
Spinacia oleracea, Distribution 725
Seed 432, f. 432, 730
Spinage syn. Spinach
Spine 870
Spiny Amaranth 697, 723
Clotbur 334, 336, 485, 486, 713, 737,
754, 821
Cocklebur syn. Spiny Clotbur

Chemical composi-

906

Knapweed syn. Knapweed
Nightshade syn. Buffalo Bur
Sow Thistle 494
Spiny-leaved
Sow Thistle syn. Sow Thistle
Spiraea 175
Distribution 693
Spleenwort 5
Spooner, A. 766
Sporangium 616, 870
Spore 870
Sporobolus neglectus 38-39, 790, f. 39
Distribution 715, m. 39
vaginiflorus 37-38, f. 387
Distribution 715, m. 88
Spotted Cowbane 596
Spurge 207-208, 458, 556-557, 657,
718, 788
Large 660, 718
Spraying 847, 848, 849, 850, 851, 852
Spreading Amaranth syn. Prostrate
: Pigweed
Dogbane 235, 237, 719, 788
Pigweed syn. Prostrate Pigweed
Spring Beauty 134
Spring grain field, Weeds of 661
Sprouting Crab Grass 14-15, 410, 691,
714
Spruce 3, 6
Spurge, Creeping 208-209, f. 209
Distribution m. 209
Seed 458, 557, f. 451, 557
Cypress 212-213, f. 212, 735
Distribution 718, 736, m. 213
Seed 557, f. 587
Family 205-213
Distribution 724
Seed 457-458, 556-557
Flowering (corollata) 210, f. 211
Distribution 718, 690
Seed 458, 596, f. 458, 597
Flowering (maculata) syn. creeping
spurge
Flowering Spotted
spurge
Milk syn. Creeping Spurge
Prostrate syn. Creening Spurge
sp. 658, 659, 660, 664. 786, 787, 819
Spotted 207-208, 657, 718, 788, f. 208
Distribution m. 208
Seed 458, 556-557, f. 458
Large 660, 718
Upright syn. Spotted Spurge
Yellow syn. Cypress Spurge
Spurrey 120, 664, 665. 677
Chemical Composition 674
Distribution 723
Corn, see Corn Spurrey
Squash 6
Squaw-weed f. 623
Squires 766
Squirrel-tail Grass 58-61, 788, f. 59, 60
Chemical Composition 60-61
Distribution 691, 693, 715, 729, 730,
m. 60
Puccinia on 680, f. 678, 679
Seed f. 730
Sauiene) tail Grass (H. murinum) 677,
98

(preslii) syn.

Small 787
sp. 729
Stachys palustris 789
Distribution 743
Stadler 583
Stamens 609-610, 615-617, f. 609, 615
Diadelphous 609, f. 610
' Epipetalous 609
Monadelphous 609. f. 610
Staminate flowers 605, f. 606, 607
Star Thistle syn, Knapweed
Starch cell, see Cell, Starch
parenchyma f. 518

INDEX

Stebler, F. G. 828, 852

Stellaria media 121- 122, 663, 776, if. 121
Distribution 696, 716, 725, m,. 122
Seed 435, 810, f. 435

Stem EHelworm 677

Stemless Lady Slipper 702

Loco Weed syn. Purple Loco eed

Stems, Underground 651-653, f. 651, 652

Stereome f. 599

Sterile flowers f. 607

Stevens 760

Stevens 824

Stewart, F. C. 748, 756, 760, 767, 833,

834, 859

Stokes 766 :
Stickseed 260-262, f. 261
Distribution 719, m. 262
Seed 466, 565-566, f. 467, 565
Stick-tight syn. Beggar-ticks
Small 489, f. 489
Stickweed 180, f. 181
Distribution 717, ™m. 181
Seed 545, 829, f. 545
Stiff Goldenrod syn. Yellow-flowered
Stigma 616, 871
Papillary f. 616
Petal-like f. 617
Shield-shaped f. 618
Stinging Nettle (U. dioica) 667
(U. gracilis) 69-70, 425, 602, 603,
652, 708, 715, 788
Stink Grass syn. Candy Grass
Stinking Clover syn. Rocky Mountain
Bee-plant
Willie syn. Ragwort
Stinkweed 171-173, 793, f. 172, 178
Distribution 693, italy m. 172
California 840
Also see A LOIG LASS
Stipa 636
spartea 689, 790, f. 666, 667
sp. Distribution 701
Stipule 591, 592, 871, f. 591, 598
Stolon 871
Stoma 597, 871, f. 598
Stone, A. Ti 850, 852, 861
Stone, G. E. 833, 851, 852, 859
Stone Clover 718, 760
Stonecrop, Distribution 695
Storksbill, Distribution 713, 725, 729,

34

Seed 457, f. 457
Stramonium, Purple syn. Jimson Weed
Strap- -shaped flowers f. 611
Strawberry 175

False 175-176, f. 176

Distribution m. 176

Sino phertvies helvola 199-200, 790, f.

00
Distribution ie m. 200
Seed 455, 455
Stubbleberry sun. Black Night-shade
Studley 766
Sturtevant, E. L. 846
Stutzer, A. 673, 8387
Style 617, 871
Successful Farming .826
Succory syn. Chicory
Sugar
Cane 600
Suksdorf 751
Sumach 213
Family 218, 214, 215
Summers 746
Sunflower
Annual syn. Common Sunflower
Common 340-342, 596, 601, 789, f. 341,

342
Distribution 693, 720, 730, 756,

m. S41
Seed 487, 575, f. 487, 596

Trichomes f. 488

INDEX

Diseases 680
Family 307-404, 633
Distribution 724, 734- et 747-758
Inflorescence 614, fix 18
Seed 477-502, 574- digo”
Maximilian’s 348- 349, 790, f. 348
Distribution m. 348
Meadow 344-346, 790, i Sib 845
Distribution 691, Mm,
Petiolate syn. Prairie oe inten
Prairie 342-3438, 788, f. 343
Distribution 730, m. 843
Seed 487, f. 488
Trichomes f. 488
Saw-toothed syn. Meadow Sunflower
sp. 695, 794
Western, Distribution 689, 696
Trichomes f. 488
Wild syn. Wood Sunflower
Wood, Seed 488, f. 488
Suspensor 621, 871
Swamp Buttercup 140-141, 717, 787
Milkweed 462, 463
Sweden, Weed Seeds 829
Weeds 846
Sweet Cicely 561
Clover 794, 815, 834
White 187-190, 451-452, 548, 644,
645, 648, 718, 725, 726, 729, 760,
788, 794. 810, Sal sae 832
Yellow 186- 187, 452, 548, 713, 718,
T2255 29% 759, 776, 810, 811
Potato 241
Vernal Grass 693, 714
Switch Grass 6, 410-411
Switzerland Weeds 754, 820, 845
Symphoricarpos orbiculata 790
Symphytum officinale, Distribution 719

Tagetes erecta, Distribution 696
Tall Buttercup 440, 717
Dock syn. Smooth Dock
Five-finger 657
Hedge Mustard 789
Thistle 494
Tanacetum vulgare 364-365, 780, 790,
865

Distribution m. 365
Tandberg, G. 852
Tannin 213
Tansy 307, 364-365, 773, 780, 790, f. 365
Distribution 688, 709, 720, m. 865
Mustard 660
Tanweed 88-90, 789, f. 88, 89
Distribution 716, m. 88
Root 652
Seed f. 431
Tapetal cell 891
Beg area See esner mum 390-391,
Distribhtion 721
Seed 498, f. 498
officinale 386- 389, 676, 780, 787, 819,
f. $86, 388, 389, 743
Distribution 696, 697, 721, 736, m.

887
Seed 498, 499, 579, f, 498, 580
Tarred paper as weed exterminator 134
Tatnali 765
Taylor, F. W. 833, 860
Taylor, W. A. 836
Tea, Mexican 103-104, 790, f. 104
Distribution 738, 746, m. 104
Teasel 714
Distribution 711
Family
Distribution 724
Teilitzen, H. 849
Teindl, J. C. 861
Tener, W. E. 746
Teneriffe Weeds 693

907

Tennessee medicinal plants 853
Weeds 766
Ten Eyck, A. M. 250, 643
Testa 871
Teucrium canadense 272-273, 789, f. 273
Distribution m. 273
Seed 469, f. 470
Texas Blue Grass 639
Seed legislation 834
Thaer, A. 735, 819
Thalictrum purpurascens 688- eee
Seed 438, f. 439
Tharandt 827
Thaspium barbinode 808
Thellung, A, 846
Thistle, Distribution 821
Barnaby’s syn. Knapweed
Bull 372, 373, 789, f. 373
Distribution 687, 695, 721, 725, m.
Root system f. ne
Seed 495, f. 494,
Canada 67, 379- gn. 592, 633, 665,
788, 793, 794, 796, 803, 804, 805,
806, 807, 819, 826, 844° 847, 848,
852, f. $80, 381, 592
Distribution "688, 708, 721, 748-749,

HOuE ren 648, 651
Seed 494, 636, 810, 814, 833, 834,
f. 494, 638, 639, 676
Cotton 667, 677
Distribution 725
Family syn. Sunflower Family
Field 376-377, 789, f. 376, 377
Distribution m. 378
Root system 645
Seed 495, 577-578, f. 495, 578
Iowa 377- 379, 789, f. 878
Distribution m. 878
Seed 495, 578, f. 495
Lady’s 495, 578
Distribution 725
Pasture syn. Wavy-leaved
Prairie 376-377, f. 376, 377
Distribution m. 877
Seed 577, f. 578
Russian 67, 111-113, 789, 794, 796,
805, 807, 808, 825- 826, 845, 846,
847, 848) ifs 118 :
Chemical composition 113, 826, 837
Distribution 699, 716, 727, 728, 729,
743-746, 838, 841, m. 112
Seed 433, 532- 533, 814, 834, f. 433,
533, 631, 730
Scotch 806
Sow 393-394, 665, 673, f. 393
Distribution ios. eal m. 894
Seed 499, f. 4
Annual 391- boa "661, 676, f. 892
Chemical composition 674
Distribution 725, 735, m. 393
Seed 500, f. 499
Field syn. Perennial Sow Thistle
Perennial 394-396, 663, 808, 819,
826, f. 395
Distribution 753, m. 895
Seed 499, 814, f. 499
Spiny syn. "Sow Thistle
Sp. 664, 665, 667, 676, 677, 693, 736,
748, 786, 794, 844, 848
Star syn. *Knapweed
Tall 790
Seed 494, f. 495
Wavy-leaved 788
Root system 651
Seed 495, f. 495
Wood syn. Prairie Thistle
Woolly 374-376, 790, f. 374, 875, 749
Distribution 721, 749-750, mM. 876

908 INDEX

Thlaspi arvense 143-144, 788, f. 143
Distribution 700, 717, m. Ih
Seed 441, f. 441

Thomé XII

Thompson, J. 749

Thorn-apple 288, 289-291, f.°
Distribution 290

Purple syn. Jimson Weed

Thornber, a J. 834, 859

Thorne, C. E. 846

Thornton, R. “W. 846

Three-flowered Nightshade
Distribution 738

Three-seeded Mercury 205-207, 457,

Threshing machines scattering weeds

Legislation 794, 806-807

Thrift, f. 616

’ Thurber, Geo. 754, 82

Thyme 368
; Distribution 720
Tickle Grass syn. Old-witch Grass
Tickseed 352-354, f. 353
Distribution ™m. 354
Tilia americana, See f. 632
Tillman, O. I. 832, 860
Timothy 805, 806
Distribution 715, 785
Meadows, weeds of 144, 147, 322,
660, 845

Seed 415, 517; 674, 810, 813,
827, 828, 832, 833, f. 415, 638, 676
Tmpurities 144, 165, 674, 857

Tissue, Spongy 598

Titus, W. N. 768

Toadflax 292-294,

f. 293
Distribution 688, 696, 708,

Mm. 294
Seed 473, 814, f. 473
Tobacco 277
Flowering 277
Smooth 696
Tolf, R. 846
Tomato 6, 277
Tomentum 871
Tomson 753
Torrey, John 753, 754, 756, 759,
761, 762, 767, 768
Touch-me-not 630
Toumey, J. W. 861
Tourlet, E. H. 738, 846
Tovey, J. R. 840
Tracy, S. M. 766
Tragopogon porrifolius, Seed 497, f. 498
Distribution 696, 729
pratensis f. 498
Distribution 729, 755
Seed 497, f. 498
Trailing Arbutus 702
Wild Bean 455
Transpiration 601, 871
Transvaal, Flora of 695-696
Trapa natans, Distribution 712
Treacle Mustard 741
Trefoil, Bird’s-foot, Distribution 734
Yellow, Seed 453, 640, 787, 810, 811,
815, 831, f. 453, 638
Triboulet 852
Tribulus terrestris 203-205,
Distribution 697, m. 205
Trichome 871
Trifolium agrarium 183-184, f. 184
Distribution 734, 760
arvense, Distribution 718, 760
hybridum, Seed 450, 812, f. 441
incarnatum, Seed 812
pratense, Seed 451, 811, 812, f. 451
pratense var., Seed 811, 2
procumbens 184-185, 612, 787, f. 185
Distribution 718, 760, m. 185
Seed 451, f. 451

788, 794, 808, 849,
720,

789, f. 204

repens, Distribution 718
Seed 450, 813, f. 451
Triglochin maritima 820
Tristegis glutinosa, Distribution 693
Triticum (Wheat)
Seed 813
_ (Quack Grass) 774
Tronmer 861
Trubenbach, P.. 852
True, R. H: 855
Tschirch, A. 538, 553
Tube cell 516
Tuber 871
Tubular flowers f. 611
Tumbleweed 113-116, f. 116
Distribution 690, 698, 738, m. 116
Root system 645
Seed 434, 834, f. 434, 631
Iowa syn. Tumbleweed
sp. 788, 3
Russian syn. Russian Thistle
Western f. 100
Tumbling
Amaranth syn. Pigweed
Mustard 165-167, 446-447, 542, 544,
Tl Ws tis
Pigweed 116, 645, 790
Turnip 142
Finger and Toe Disease 677
Flea Beetle 676
Gall Weevil 676
Root system 648
Wild

i
Seed 445, f. 445
Tussilago farfara 663
Distribution 735, 736
hybrida, Distribution 736
petasites, Distribution 736
Tussock Grass 667
Twitch Grass 851
Tylenchus devastatrix 677

Ulex 667
Uloth, W. 583, 586
Umbel 612, 871, f. 612, 61}
Umbellifer 785 :
UMBELLIFERAE 4, 224-234, 776, 864
Bibliography 587
Distribution 719, 725, 734
Seed 460-462, 561-562, 767-769
Umbrella Plant, Seed 533, f. 534
United States, Weeds 840
Upham 751
Upright Spurge syn. Spotted Spurge
Urban, I. 731
Urtica dioica 667
Distribution 736
gracilis 69-70, 788, f. 69
Chemical composition 70
Distribution 715, m. 70

Root 652
Seed 425, 525, f. 425, 525
urens

Distribution 736
URTICACEAE 3, 69-74

Bibliography 587

Distribution 715, 725

Seed 424-425, 524-
Utah Weeds 712, 728, 747, 757, 769
Utricle 871

Vahl, M. 701
Valerian Family, Distribution 725
VALERIANACEAE, Distribution 725
Valve 871
Vandevelde 828, 830, 859
Vanilla Grass sun. Holy Grass
Vasey, George 371, 751, 846
Vegetable Oyster 497, 498, 729
Vein 871
Veining of leaves 592

Netted 592

INDEX

Palmate 592
Parallel 592
Pinnate 592
Velvet-leaf syn.
Grass 693
Weed syn. Indian Mallow
Venus’ Comb 663
Distribution 736
Verbascum blattaria f. 292
Distribution 720
Seed 472, f. 473
thapsus 291-292, 777, 789, f. 291
Distribution 720, 727, mv. 292
Seed 472, f. 478
Verbena, Bracted syn. Bracted Vervain
bracteosa 267-268, Ul
Distribution 690, 719, m. 268
Seed 468, 7. 468
Creeping Sun Prostrate Vervain
Family 263-26
Distribution 725
Seed 468-469, 566
hastata 263-264, 777, 789, f. 26%
Distribution 704, 719, m. 264
Seed 469, f. 468
sp. Distribution 701 "
stricta 264-265, 789, f. 265
Distribution 689, 690, 719, mv. 265
Seed 469, 566, f. 469, 566
urticaefolia 264, 267, f. 266
Distribution 704, m. 267
Root 654
Seed 469, f. 469
VERBENACEAE. 263-268
“ Distribution 719, 725
Seed 468-469, 566
Verbesina helianthoides, Seed 575, f. 577
Vermont
Seed investigations 833, 857
Weeds 747, 842
Vernal Eee: Sweet, Distribution 693,
71
Vernonia baldwini 309-310, f. 310
Distribution m. 310
Seed 477, f. 477
fasciculata 310-311, f. 311
Distribution m. 311
Seed 477, f. 477
Veronica arvensis
Distribution 723
peregrina 296, 297, 787, f. 296
Distribution 704, 720, 723, m. 297
Seed 473, 829, f. 474
sp. 659, 66
Vervain, Blue, 263-264, 777, 789, f. 264
Distribution 689, 690, 719, m. 264
Seed 469, f. 468
Bracted syn. Prostrate Vervain
Family 263-268
Distribution 263-268
Seed 468-469, 566
Hoary 264-265, 659, 789, f. 265
Distribution 719, m. 265
Seed 469, f. 469 :
Large-bracted syn, Prostrate Vervain
Nettle-leaved syn. White Vervain
Prostrate 267-268, 787, f. 267
Distribution 690, 719
Seed 468, f. 468
White 264, 267, f. 266
Distribution ™m. 267
Root system: 645, 654
Seed 469, f. 469
Vetch
Common 197-199, 596, 663, 787, f. 198
Chemical composition 198
Distribution 692, 696, 697, 699, 709,
- 718, m. 198
Seed 455, 553, f. 455, 551
Dakota, Distribution 761
Hairy. Distribution 718, 735
Seed 455, f. 455
Milk 193- 194, f. 19%

Indian Mallow

909

Spring syn. Common Vetch
Vetchling 693
Vicia americana 688
hirsuta, Distribution 735
sativa 197-199, 596, 668, 787, f. 198
Distribution 692, 696, 697, 699, 718,
m. 198
Seed 455, 553, f. 455, 551
villosa
Seed 455, f. 485
Viability of seeds, Standard 812-813
Victoria, Weeds 840, 841
Vienna flora $43
Vilke, A. 829
Vinall, H. N. 836
Viola arvensis, Distribution 722
cucullata f. 598
Family, Distribution 725
sp. 663
tricolor, Distribution 727
VIOLACEAR, Distribution 725
Violet, Blue 598
Root-rot 677
sp. 663
Violet-colored seeds 828
Viper’s Bugloss, Seed 488, f. 468
Virginia Catchfly 535
Creeper 213
Ground Cherry 279, 281
Peppergrass syn. Large Peppergrass
Vitality of seeds 821, 828, 829, 830, 831,
832, 833, 835, 836, 837, 855, 856,
857, 858, 859
Vitek, BE. 861
Voelcker, J. A. 846, 852
Vogl 538
Von Degen 828

Waddell, C. H. 846
Waldron, L. R. 839, 846, 852, 859, 861
Wall Pellitory if 597
Wallace, Henry 751
Wallace’s Farmer 80, 90, 113, 119, 216,
241, 247-248, 250, 254, 305, 307,
310. 3225 328, 337, 382, 826
Walters, i. G 768
Warming, Hug. 701
Warneke, 830, 857
Washington seed legislation 809
Weed legislation 794
Water Chestnut 712
Cress 142, 717
Hemlock syn. Cowbane
Hemp 118-119, 435, 716, 789
Parsnip 734
Pepper 92-93, 429-430, 734, 775, 789
Mild 95-97, 429-430, 594, "788
Seeds scattered by 629, 587, f. 630
Smartweed 96-97, 428
Waterleaf 254
Distribution 719
Family 254-256
Waterweed, Distribution 740
Waterwort Family, Distribution 724
Watson, E. B. 334, 681
Watson, S. 746, 757, 769
Waugh, BE. N. 749
Wavy- leaved Thistle Bap 651, 788
Weaver, A. T. 861
Weaver, C. B. 745
Weed, cM. 826,. 852
Weed, C. N. 749
Weed Commissioner, Iowa 801, 802, 803

803
Illinois 804
Community 657-661
Definition of 820-821
Distribution
Bibliography of 837-846
Geographical, Africa 722, 731, 732,
733, 734
America 698, 737-740
North 696, Vol, 32. Poon led

910

INDEX

South 696, 713, 726, 731, 732,
733, 734
Arkansas 757

Asia 731, 732, 733, 734
Brandenberg 845 g
California 708, 712, 725, 755, 757

Canada 693, 733, 753, 757, 762,
766, 825, 839
Chile 728

Colorado 745, 747, 748, 755, 757,
759

Connecticut 766
Dakota 6938, 753
North 744, 757
South 744, 756, 757, 767

Delaware 765

Denmark 753, 766, 795, 844

England 763

Europe 703, 704, 706, 713, 731,
(32, 733, 734, 737- 740, 748

Florida 762

France 753, 754, 763

Georgia 754

Germany 713, 735, 736, 753, 766,
820, 841, 845

Great Britain 660, 663-664

Gulf States 722

Hanover 753

Holland 763

Idaho 745, 757, 842, 844

Illinois 745, 751, 751, 765, 766

India 767

Indiana 747, 757, 766, 768, 838

Iowa 838, 840, 841, 844, 845, 851,
See species

Ireland 846

Kansas 708, 751, 754, 757, 766,
837, 842

Kentucky 747

Louisiana 840

Maine 750, 754, 841

Manitoba 693

Maryland 833, 84

Massachusetts 750, 754, 757, 763,

Mediterranean Region 696

Mexico 733, 767-768

Michigan 708, 757, 766, 768, 824-
825, 830-831, 838, 855

Minnesota rials, —YAnily GDB YETC
844, 845, 848

Mississippi Valley 751, 769

Missouri 754, 757, 759, 766

Nebraska 693, 745, 748, THD, 5M
765, 844, 847

Nevada 759, 842

New Brunswick 750, 762

New England 709

New Jersey 757, 765, 841

New Mexico 757, 846

New South Wales 843

New York 747, 750, 757, 760, 765

Newfoundland 734

Norway 852

Nova Scotia 756

Ohio 747, 753, 757, 766, 825, 842,
843, 845

Oklahoma 838
Ontario 747, 841, 842,
Oregon 747, 750
Pacific Coast 725, 750
Papua 733, 734

Fenn ae 750, 759, 765, 768,
Peru 753

Prussia 754,

Puget Sound 727

Quebec 768

Queensland 838

Red River Valley 751

Rhode Island 766

Rocky Mountains 729

Russia 757, 829, 843, 844

843, 858

Saxony 845

Siberia 757

Silesia 754

South America 696, 713, 726,
Wie" so hop Mont

South Dakota 744, 756, 757, 767

Sweden 846

’ Switzerland 754, 820, 845

Tennessee 766

United States 840

Wtah T2728) (47, ipioe aoe

Vermont 747, 842

Victoria 840, 841

West Virginia 843

Wisconsin 745, 747, 751, 754,
oe 760, 762, 766, 767, 841,

Wyoming 757, 844
Yellowstone Park 757
Yorkshire 825, 845
Eradication 846-853
Also see species
Inspectors 793, 852
Legislation 794-808
Alberta 793
Australia 793
Connecticut 830
Delaware 794
France 795
Germany 795
Illinois Toa. 803-804
Indiana 747, 757, 766, 768, 838
Iowa 794, 801
Isle of Man 793
Kansas 794, 805
Kentucky 794
Manitoba 793
Michigan 794
Minnesota 794, 805-806
Missouri 794, 6
Nebraska 794, 806
New Jersey 794
New York 794
North Dakota 794, 806-807
Northwest Territories 793
Ohio 794, 807-808
Oregon 794
Pennsylvania 794
Quebec 793
Saskatchewan 793
South Dakota 794, 808
Washington 794
West Virginia 794
Wisconsin 794, 808, 809, 814
Scattering 630-640, 687-770, 837-846
Weeds and moisture 671-673
Weeds, Diseases of 677-681
Food of 673-674
Injurious 671-683
Weekly Register 273
Mice B. 10, 17, 19, 46, 48, 57, 60,
Wegelin 737
Weinhold 82
Wells, C. A. 756
Weschke, C. 855
Weshoff 740

“West Indies, Flora of 731

Virginia weed legislation 794

Weeds 843
Western Ironweed 310-311

Lamb’s Quarters 432

Mugwort 366- 367, 790

Ragweed 484

Tumbleweed 100

Wheat Grass 53, 56. 4238, 715

Westgate, J. M. 187, 838
Wheat, 6, 8, 139
Grass, Awned, Distribution 715
Slender 53
Distribution m. 57
Seed f. 422
sp. 844

INDEX 911

Western 53, f. 56
Distribution 715, m. 56
Seed 423, f. 423
Mustard 155
Powdery mildew of f. 682
Rust of 678, 680
Screenings 810
Seed 813
Impurities 674, 709, 829
Transpiration of 673
Wheeler 753
White, G. C. 748
“White-man’s Foot” 710
White, P. J. 846
White Aster syn. Many-flowered Aster
Avens syn. Stickseed
Gompion 126-128, 638, 664, 716, 810,
ake
Charlock syn. Jointed Charlock
Clover 183-184, 638, 718, 830, 831
Cockle syn. White Campion
Mildew 85
Mustard 14, 142, 444, 663
Pine 6
Radish 845
Root-rot 678
Rust 677, f. 681
Snakeroot 312-313, 477, 478, 780, 789
Sweet Clover 187-190, 451-452, 548,
549, 550, 644, 645, 648, 718, 725,
726, 729, 760, 788, 794, 810, 811,
831, 832
Vervain 264, 266, 469, 645, 654
Wormwood 366-367
White-leaved Franseria 484, 485
Whiteweed 321-322, 595, 788, f. 321, 621
Distribution 695, 720, 737, m. $22
Seed 482, f. 481
Whiting, W. S. 768
Whitson, A. R. 846
Whitlavia grandiflora, Seed 829
Whorl 872
Whorled Foxtail syn. Bristly Foxtail
Milkweed 463
Millet syn. Bristly Foxtail
Wilcox, E. M. 833, 852
Wilcox, E. V. 852
Wilcox, Fred 766
Wild Balsam Apple 573, 574
Barley syn. Squirrel-tail Grass
Bean 199-200, 455, 718
Trailing syn. Wild Bean
Black Cherry 637
Buckwheat 97-99, 429, 528-529,
531, 532, 536, 686, 674, 814
Carrot 227- 228, 635- 637, 667,
688, 692, 698, 712, 767-76
783, 794, 796, 802, 819, 83
Comfrey 258-259, 466, 564- 56
Cranesbill 718
Endive 793
Four-O’clock 119-120, 533, 534, 660,
716, 787
Foxglove, Yellow 702
Garlic 67, 787
Heliotrope 695
Hemp 645
Lettuce 399-400, 500. 501. 595, 645,
780, 788. 807, 838, 846
iauerice peek Hol, 554s 718; 729;

0,

’

53
676
786,

’

8
3
5

Marjoram 693

Morning Glory 241, 245-248, 464, 563,
564, 624, 649, 651, 652, 660, 674,
671, 719, 787, 789, 848

Mustard 155-157. 727, 736, 787, 793,
794, 796, 807. 808, 810, 811, 849

Oats 8, 40-41, 415-416, 664, 665, 679,
(oe 736, 789, 793, 794, 810, 814,

Onion 67, 623, 814, 852
Pansy 722
Parsnip 228-230, 461, 462, 648, 719,
794, 796
Pea 790
Peppergrass syn. Large Peppergrass
Prairie Rose 178-180
Radish 134, 673
Rose 178-180, 449, 450, 632, 717
Rye 680
Sunflower 488
Timothy 35-37
Turnip 445
Willey 748
Williams, F. A. 765, 826, 852, 861
Williams, George 766
Willow, 3, 605, f. 607
Family, Distribution 724
Primrose, Distribution 734
Willow-leaved Aster 319-320, 481, 790
Wilson, A. D. 852, 861
Wilson, F. W. 853
Wilson, James: 825, 846
Wilson, J. K. 859
Wiltz, Albert 337
Wind as seed distributor 629, 687, f. 631
Wing 872
Winged Pigweed 99-101, 451, 693, 716,
730, 740, 746, 788
inter annuals 647-648, 660, 785, 786,
: 2,

Cherry 623
Chess 170-171, 447
Cress 170-171, 447-448, 542, 544, 677,
717, 733, 744
Winton, A. L. 21, 48, 107, 138, 190, 299,
303, 364, 389, 505, 506, 511, 517,
520, 524, 528, 536, 554, 575, 581,
582, 583, 584, 585, 586, 587, 837
Wire Grass 41-43, f. 42
Chemical composition 43
Distribution 697, 715, 741,
Seed 418, f. 418

mM. 42

. Wisconsin drift, Flora of 689-692

Farmer 251-252
Seed legislation 834
Weed legislation 794, 808, 809, 814
Weeds 745, 747, 751, 754, 757, 760,
762, 766, pee 841, 845
Wittrock, V. B. 53
Wollny, B. 828, BAe, 859
Wood Hair Grass 639
Sage 272-273
Sorrel Family 199, 201-203
Sunflower syn. Wild Sunflower
Thistle syn. Prairie Thistle
Woodbine Family 307
Woods, A. F. 836, 853
Woods, C. D. 832, 8538, 860
Woolen Mills, Weeds spread by 711
Woolly Soft Grass 665
Thistle 374-376, 721, 749-750, 790
Wooten, E. O. 826, 846
Wormseed 103, 174
Distribution 696
American 775, 855
Wormwood, Biennial 367- 368, 790, f. $67
Be (21, m™. 368
Seed 492, 492
White 366 Ber, f. 366
Distribution m. 367
Woundwort 789
Wrapp, J. M. 756
Wright, R. P. 830
Wyoming forage plants 837
Weeds 757, 844

Xylem f. 598
Xanthium canadense 334-337. 796, f. $35,

682
Distribution 720, m. 335

912

Seed 485, f. 485
sp. Distribution 704
Seed 829, 861
spinosum 335, ie
Distribution bog” 113, 737, 754
Seed 485, f. 485
strumarium 486
Xylem 872
Xylopleurum tetrapterum, Distribution
696

Yard Grass syn. Crowfoot Grass
Yarrow 358-360, 778, 787, f. 359, 741
Chemical composition 673, 674
Distribution 698, 704, 708, 720, 736,
m. 3859 :
Seed 491, f. 491
Yellow Clover 183-184, 450, 451
Dock syn. Curled Dock
Foxglove, Wild 702
Foxtail 17-20, 413, 511-512, 616, 657,
; 658, 659, 660, 676, 691, 714, 789
Oxalis 199, 645

INDEX

Rattle 667, 742

Rocket syn. Winter Cress

Sorrel, Field syn. Field Sorrel

Spurge syn. Cypress Spurge

Sweet Clover 186-187, 452, 548, 713,
118,725, 729, 759; 776; (SL0ses it

Trefoil ape 640, 787, 810, 811,

Yellow-flowered Goldenrod 316-317,
480, 689, 738, 790

Yellowstone Park, Weeds of 757

Yorkshire Fog 665, 667

Yorkshire Weeds 825, 845

Young, F. B. 855

Yucatan Flora 731

Zapparoli, T. V. 829, 858
Zeeuw, R. 831
Zea mays f. 505

Seed 813
Zinger, N. 853
Zinnia pauciflora, Distribution 696, 698
Zurich Seed Control Station 828
ZYGOPHYLLACEAE 4, 203-204

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