A Talk on Weeds

LIBRARY

THE UNIVERSITY
OF CALIFORNIA

SANTA BARBARA

PRESENTED BY

F.E. CLEMENTS

A Talk on Weeds

An address delivered before the County
Road School, Clinton County, Iowa, 1910,
with an appendix describing a few weeds

BY

L. H. PAMMEL, PH. D.

PROFESSOR OF BOTANY, IOWA STATE COLLEGE
AMES, IOWA.

Copyright 1910 by
L. H. Pammel

Table of Contents

PAGE

What is a Weed, Kinds of Weeds, Annual, Winter Annual 5

Biennial, Perennial, How Weeds Spread, Vegetative Propagration. . . 6

Seed Propagation, Dissemination or Scattering of Plants 7

Water, Animals 8

Explosive Properties, Seeds Burying Themselves 9

Man as an Agent, Impure Seeds 10

Iowa Pure Seed Law 11

Threshing Machines, Cultivation, Packing Material, Plants, Culti-
vated for Ornamental Purposes, Iowa Weed Law 16

Other Weeds, Treatment of Weeds 20

Perennial Weeds 21

Quack Grass, The Cover Method, Canada Thistle and Horse Nettle. . .22

Morning Glory and Milk Weed 23

Indian Mallow 24

Sweet Clover, Greater Ragweed or Kinghead, Cocklebur 25

Weeds of Special Crops, Small Grain, Corn 26

Garden Weeds, Meadows, Pastures, Roadsides, Poisonous Weeds 27

Grass Family, Yellow Foxtail 30

Green Foxtail, Quack Grass 31

Drop Seed Grass, Squirreltail Grass 33

Crab Grass, Sedge Family, Dock and Smartweed 34

Curled Dock 35

Pale Dock, Sheep Sorrel 36

Goosefoot Family, Pigweed Family, Pink Family 37

Purslane Family 38

Crowfoot Family, Mustard Family 40

Mallow Family 41

Velvet Weed, Parsley Family 42

Parsnip, Carrot 43

Oowbane 44

Morning Glory, Dodder 45

Mint Family 47

Nightshade, Horse Nettle 48

Plantain, Buckhorn, Composite, Bull Thistle 49

Canada Thistle, Cockle Bur, Ragweed 50

Burdock 51

Suggestions for the Teacher 52

Questions and Topics 53

Bibliography 55

A STUDY OF WEEDS IMPORTANT

I am invited to address you this afternoon on the subject of
weeds. I am sure you will agree with me that this is a most
important subject for the farmers of Iowa and those who are in-
terested in making our state beautiful. The weeds in villages,
cities, along the highways and on our farms are a continual men-
ace to the agriculture of this state. It is important that we be-
gin to realize the menace that weeds are to our agriculture. Iowa
should realize the importance of this problem and we should be-
gin at once to clean up, because it is far more economical to do
so now than in a decade.

WHAT IS A WEED.

A weed has been defined as a plant out of place. This defini-
tion is concise, but is as good as any. Oats growing in a wheat
field, if not wanted there, must be looked upon as a weed. A
weed may also be defined as a plant detrimental to the growth
of a garden or farm crop, in short detrimental to horticulture
and agriculture. A great many people regard plants which have
inconspicuous 'flowers as weeds; they exclude, of course, such
plants as are cultivated for some purpose. Such people regard
the inconspicuous plants of the forest as weeds, forgetting that
plants like the Dutchman's Breeches, Bloodroot and Hepatica
are most useful plants in the forest and are just as much a
part of it as the oak or maple. They do not, however, regard
blu' £rass as a weed. In the forest, however, bluegrass must be
reg /rded as a weed. In a bluegrass pasture such plants as f ox-
tai/, golden rod, vervain and crabgrass are weeds. They check
the growth of this useful forage plant.

KIND OF WEEDS.

Weeds may be classified according to their duration of life
into the following classes; annual, winter annual, biennial and
perennial.

Annual. — The annual weeds are the most numerous and are
easily recognized. The seed germinates in the spring, it sends
up a stem which produces flowers and seeds the same season and
then dies. Foxtail, ragweed or kinghead, smartweed, crabgrass,
horseweed belong to this class. A large number of our weeds
belong to this class.

Winter Annual. — These weeds do not differ essentially from

the annual. The seed germinates in the fall, a mat of leaves is
produced and the next spring a stalk is sent up which produces
flowers and seed, then dies. Shepherd's purse, wild barley or
squirrel tail, pepper grass in our climate, but in the south
many more weeds belong to this class. Winter wheat and win-
ter rye are winter annuals.

Biennial. — The seeds of biennial weeds germinate in the spring,
the plant produces a mat of leaves with a short stem, it passes
through the winter in this way, the next season it sends up a
stem on which flowers and seed are produced. This ends its
existence. Burdock, Parsnip, Carrot, Mullein, and Bull Thistle
are representatives of this type. These weeds are common every-
where in the ?tate.

Perennial. — Ti^ nerennial weeds are often long lived. The
seed germinates, somtL'mes a stalk with flowers is produced the
same season. The ^lant continues to live year after year. Peren-
nial weeds are thv most difficult to exterminate. Weeds of this
type are numerous and in Iowa are represented by Canada
thistle, Morning glory, Milkweed, Quack grass, Nimble will.

HOW WEEDS SPREAD.

Weeds spread in two days by (1) vegetative propagation and
(2) seed production. Some weeds have both methods, some
only one.

Vegetative Propagation. — In this method of reproduction the
stem or root serves to propagate the plant. This is brought
about in three ways, (a) by stem above ground or under-

Tumbleweed (Amaranthus graecizans) . Scattered by the wind against
fence. ( Bergen. )

ground. The stem may be recognized through the presence of
leaves or scales. Quack grass, Germander, Northern nut grass,
and Morning glory spread by stems. The Quack grass stems,
called roots commonly are near the surface of the soil, some-
times over three feet long, and every severed part gives rise
to a new plant, (b) These plants spread by roots, sometimes
they are flehsy and in other cases they are thin and slender.
Dock, Horseradish, Horse nettle, Sheep sorrel and Dandelion. The
Milkweed spreads horizontally in the soil and may attain a length
of 14 feet. The roots of the Horse nettle on the other hand
spread deeply in the soil, sometimes to a depth of three and one-
half feet. These roots, when severed give rise to new plants,
buds forming on these roots, (c) The third type propagates
partly by root and partly by stem. The upper part of the
Canada thistle is stem, bearing minute scales (leaves), the lower

root which develops buds.

Seed Propagation. — The vast majority of weeds produce seeds.
The only weed in the state which has never been known to pro-
duce seed is the Horse Radish. It flowers frequently but seeds
are never produced. The Canada thistle blossoms freely but it
does not seed abundantly. At least this is true for Iowa. It
relies chiefly, therefore, on vegetative reproduction. The quack
grass spreads as freely by seeds as by its underground stems.
Some weeds produce an enormous number of seeds, from a
few thouand to over a hundred thousand on a single plant. A
single seed of Squirrel tail grass germinates, from this seed a
large number of stems arise, each with a spike that contains 50
or 60 seeds, so that the progeny soon becomes greatly multi-
plied.

Dr. Beal estimates that a large purslane plant produces 1,250,-
000 seeds, a patch of daisy fleabane 3,000 to the square inch.
We found the following number of seeds per plant, horseweed
324,000; pigweed, 115,600; Jimson weed, 89,100. Dr. Halsted
found seeds in some weeds as follows: Speedwell, 186,292;
Shepherd's purse, 17,600; Pepper grass, 12,225; Charlock, 9,900.
Hitchcock and Clothier record the weeds seeds as follows : Yellow
foxtail, 113,600; stink grass, 180,000; cocklebur, 9,700.

DISSEMINATION OR SCATTERING OF PLANTS.

The scattering of plants is called dissemination and this is
accomplished in the following ways: (a) wind; (b) water; (c)
animals; (d) explosive properties; (e) seeds burying them-
selves; (f) man as an agent.

Wind. — The wind is an important agent in a large number
of weeds. The dandelion may serve as an illustration. The
"seed" is cylindrical with a long beak, coming from the beak

7.

are a large number of fine threads, collectively called the pap-
pus. These give it a parachute-like arrangement and permit the
seed to sail through the air. This weed owes its wide distribu-
tion to the facilities for dissemination. Canada thistle, Bull
thistle, Horsewced and many plants of the Sunflower family have
similar contrivances. The Tumbleweed is another type of weed

a — Seed of beggar-tick's, ft — Spanish needle carried by animals. (C. M.
King.)

Seeds carried by the wind: a — golden rod, 6 — blue lettuce. (C. M. King.)

disseminated by the wind. The plant grows in circular form and
when mature is severed from the root close to the ground. In
this form it rolls over and over scattering the seed. The Rus-
sian thistle is like it, but each seed is attached by a slender thread
like body which becomes severed from the plant, drops the seed
as it rolls over the ground.

Water. — Weeds are scattered by the water in two ways (a)
in a mechanical way, the seeds, plants or roots are carried by
the water. I have seen fields covered with wild oats that had
come from higher ground along the streams or ridges, stems of
Quack grass have been scattered by the water in this way. (b)
Many seeds have bladders filled with air, as in Dock. The
three cornered seed is surrounded by the calyx; one or more of
the lobes contain a cylindrical body called the tubercle, this is
filled with air and makes the seed boyant which enables it to
float down the stream and scatter the seed wherever it is lodged.
The seeds of Peppergrass when moistened become mucilaginous
and cling to the hoofs of animals or shoes and in this way steal
a ride.

Animals. — Various animals like cattle, sheep, horses, squirrels,

8. t , __

birds, etc., scatter seeds and fruits. This is done in two ways:
(a) Where the fruit or seed is edible as in the black night shade,
cherry, poison ivy, seed of dandelion, thistle, etc., crows scatter
large numbers of seeds of the poison ivy. Millions of these
poison ivy seeds are annually consumed by birds. Large num-
bers of seeds of the dandelion, thistle, foxtail are consumed by
birds some of these are accidentally scattered in this way. Birds
are undoubtedly useful, however, in destroying large numbers
of weed seed. The colored fruits usually have hard seeds so
that they can pass the digestive tract of birds uninjured, (b)
In the second type the seeds cling to animals. Many of our
weeds have excellent contrivances for such dissemination. We
will mention in this connection the cocklebur. Each cocKlebur
has two so-called seeds. The bur is provided with hooks tna«
cling to any passing animal and I have seen them scattered for
miles. The Burdock, another plant of the same family, has num-
erous seeds in a head; the hooked appendages get in the hair,
tails of horses, cattle, etc., where they form balls and thus the
seed is scattered. The Spanish needle or boot jack of the same
family has a flattened seed with two slender pointed bodies that
are barbed downwardly like grappling irons ; these cling to pass-
ing animals and carry the seed. Another weed, the Tick Trefoil,
belonging to the Pea family has a pod containing several seeds,
this pod breaks up into separate pieces when ripe, each contain-
ing a single seed. The pod is provided with hairs that are hooked
and so clings to animals. When removed the seed has often trav-
eled a long distance with the animal. Many other seeds of this
family like Licorice may be mentioned. Weeds with similar
contrivances are found in members of the Borage family, like
Hound's tongue, stickseed, etc.

Explosive Properties. — The seeds of a few weeds have explo-
sive properties. The seeds of the common yellow field sorrel has
a straight pod which, when mature and touched, shoots out the
seed like shot from a gun. The pods of certain vetches contract
and twist when mature, forcing the seed out. Contraction of
capsule of the three-seeded mercury scatters the seed, throwing
it some distance. This method of scattering can be observed bet-
ter on such a plant as the common Castor oil bean.

Seeds Burying Themselves. — A few of our weeds bury their
seed, but the needle grass growing on our dry sterile hills has
a sharp point to its "fruit," with small hairs which point obli-
quely upward. There is also a long awn to the fruit, this is sen-
sitive to moisture, it contracts when dry and straightens out
v hen moist and in this way buries the seed.

MAN AS AN AGENT.

Man is an agent in many different ways of which the follow-
ing may serve as illustrations: (a) impure seeds; (b) railways;
(c) vehicles; (d) threshing machines ; (e) cultivation; (f) pack-
ing materials; (g) wool; (h) plants cultivated for ornamental
purposes; (ij cultivated for food.

Impure Seeds. — Many weed seeds are scattered with various
agricultural and garden seeds. Buckhorn, dodder, wild carrot,
ragweed, nimble will, bracted plantain, dock, quack grass, chic-
ory, Canada thistle and many other weeds have been scattered

Some of the impurities found in alfalfa : la — alfalfa seed, Ib — toothed
bur-clover, Jc — spotted bur-clover, 2c — yellow trefoil, 2b — seed natural size,
Sd — pod, Sa — sweet clover, 36 — seed natural size, Jc — bracted plantain (Plan-
tago aristata), 5 — buckhorn (Plantago lanceolata) , 6 — sour dock, 7 — Canada
thistle, 8 — dodder, 9 — quack grass, 10 — sheep sorrel, 11 — wire grass or Canada
bluegrass (Poa compressa), 12 — bluegrass. (Lettered figures after Hillman.)

with Agricultural seeds. One farmer in Iowa sent to rne twenty
different kinds of weeds found in his clover meadow which were

10.

introduced with clover seed. In some cases it is difficult to
separate the weed seeds from clover seed as dock, buckhorn and
bracted plantain. In other cases there is no excuse for the pres-
ence of these weed seeds. One can nearly always tell where the
seed comes from because of the presence of certain weed seeds.

It may be of interest to give a few statistics on the weed seeds
commonly found in some of our agricultural seeds.

Kind of Seed

Purity

Vitality

Iowa Standard
Purity Vitality

Alfalfa

../... 91 1

87.6
87.8
87.
76.6
84.1
60.

96.
92.

90.
96.
90.

80.

80.

75.

85.
85.

Red Clover

966

Alsike Clover

98 6

White Clover

98.9

Timothy

98 9

Millet

96.

The more important impurities found in red clover vary with
the season. The imported seed may contain Canada thistle,
dodder, buckhorn, evening catchfly, wild carrot. Iowa grown
clover seed usually contains none of the above, but ragweed, dock,
smartweed, plantain, dropseed grass, foxtail and sheep sorrel are
common. Western grown alfalfa may contain black medick, burr
clover, chicory. The seed of sheep sorrel, yellow foxtail and
curled dock may also occur. Baehellor's button seed as well as
that of evening catchfly indicates European grown seed. Tim-
othy seed generally contains peppergrass, curled dock, common
plaintain. The seed of oats may contain quackgrass and mus-
tard. Wheat seed contains the seed of vetch, corncockle, chess,
cowherb and mustard.

IOWA PURE SEED LAW.

Seed Legislation. — The Iowa law has the following provisions
in regard to the sale of seed:

Sec. 9. The term, agricultural seeds, as used in this act, shall
include the seeds of the red clover, white clover, alsike clover,
alfalfa, Kentucky blue grass, timothy, brome grass, orchard
grass, red top, meadow fescue, oat grass, rye grass and other
grasses and forage plants, flax, rape and 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 (Cnicus arvensis),
wild oats (Avena fatua), clover and alfalfa dodder (Cuscuta

n.

epithymum), field dodder (Cuscuta arvensis), and corn cockle
Lychnis githago). *

Sec. 11. The seeds of the following weeds shall be considered
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 ves
pertina), night flowering catchfly (Silene noctiflora), curled dock
(Rumex crispus), smooth dock (Rumex altissimus), sheep sor-

Impurities found in red clover: 1 — bull thistle. 2 — Canada thistle. 3 —
green foxtail (Setaria viridis), 4 — common plantain (Plantago Rugelii), 5 —
pepper grass (also found in timothy), 6 — chicory, 7 — pigeon grass (Setaria
glauca), 8 — crabgrass (Panicum sanguinale), 9 — old witch grass, 10 — timothy.
11 — wild carrot, 12 — pigweed (Amaranthus rctroflexus ) , 13 — smartweed (Poly-
gonum Persicaria), 14 — lamb's quarter, 15 — dropseed grass (Muhlenbergia).
(Charlotte M. King.)

*The scientific names have been changed since this law was enacted.
The botanical names now recognized are as follows: — Common Mustard
or Charlock (BRASSICA ARVENSIS) Canada Thistle (CIRSIUM ARVENSE)
Corn Cockle (AGROSTEMMA GITHAGO) The weed law has the names
now generally recognized.

12.

rel ("Rumex acetosella), yellow trefoil (Medicago lupulina), burr
clover (Medicago denticulata), sweet clover (Melilotus alba and
officinalis) black mustard (Brassica nigra), plantain, buckhorn
(Plantago lanceolata), bracted plantain (Plantago aristata),
bindweed (Convolvulus 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 each shall be plainly indicated in
statement specified in Section One (1) of this act.

It will be seen from the above extracts that seed cannot be
sold that contains more than two per cent (2%) of the weeds
specified in Section Eleven. An amendment was made to Sec-
tion Ten stating that the weeds specified therein must not be
present in quantities of more than one in ten thousand, and
that due diligence has been used to find and remove said seeds.

The Iowa law has greatly improved the quality of seed sold in
the state. The farmers are demanding a better quality of seed.
The seed merchants will supply the demand but the seeds can-
not to be sold for the same price. In cleaning there is consider-
able loss and the farmer should be willing to pay for this. It
will cost more to remove the bad weeds than the additional
price paid for the better seed.

SOME WEED SEEDS

Characters of a Few Weed Seeds. — The seeds of Canada, thistle
are about 1-8 of an inch long, lance shaped in outline, tapering
towards the base, the upper part is cup shaped, with a yellowish
rim, a conspicuous point appearing in the center. The Bull
thistle is much like it, but larger. The seeds of dodder vary
from 1-16 to 1-24 of an inch in diameter, somewhat flattened
and egg-shaped ; the color varies from yellowish to light or dark
green, rough and dull, not smooth as in clover and alfalfa.
There are two forms of dodder, the field dodder with large seeds
and the clover dodder. The seeds of quack grass are sometimes
difficult to distinguish from some related species and should be
submitted to a botanist. Bull. 115 of the Iowa Agricultural Ex-
periment Station describes them.

The seeds of Ribgrass or Buckhorn are about 1-10 of an inch
long, shiny, smooth, dark brown, the back is convex, the rounded
edges folded inwardly forming a. rim. The long longitudinal
groove of the inner face with a dark colored spot in middle. The
Bracted plantain is a smaller seed broader and light brown in
color, a long groove in the center, on the back is a circle. Two
light colored circular areas in groove are characteristic. The
seed of the Common plantain is black, roughened, flattened with

13.

acute edges; they are rhomboidal in outline, from 1-12 to 1-16
of an inch in length. The seeds of the Common pigweed are egg-
shaped or lens shaped when viewed from the rim or border ; they
are about 1-24 of an inch in length, smooth and shiny. The
seed of Goosefoot or Lamb's quarter occur in several forms, us-
ually nearly spherical with attached parts of the flower, the
calyx showing ribs. They are dull brown in color. Others with
a thin membranceous covering. The "seed" is about 1-20 of an
inch in diameter, nearly spherical, edges somewhat rounded, sur-
face somewhat uneven, jot black in color, sometimes brightly
polished. The "seeds" of Chicory are characteristic about 1-10
of an inch in length, marked by longitudinal lines and cross
lines. The apex with a double row of whitish scales, color dull,

Fig. 5 — 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 ; fc, lamb's-
quarters; I, shepherd's-purse ; in, mayweed; n, scentless camomile; o, white
campion; p, night-flowering catch-fly; q, oxeye daisy; r, small-fruited false
flax ; s, cinquefoil ; t, two kinds of peppergrass ; u, catnip ; v, timothy ; x,
chickweed ; y, Canada bluegrass ; z, clover-dodder ; I, mouse ear ; 2, knot-

frass ; 8, tumbling amaranth ; -}, rough amaranth ; 5, heal-all ; 6, lady's thumb ;.
Enlarged.) (Hillman. U. S. Dept. Agr.)

very dark, brown to straw color. The seeds of Bachellor's but-
ton are oblong or obovoid, compressed or 4-angled, smooth and
shining attached obliquely with a disk on top and an elevated
margin. These seeds occur in alfalfa.

The seed of May weed sometimes found in clover is about 1-16
of an inch in length, bristly club-shaped, the base wider than
apex, prominently ribbed and tubercled. The "seed" of Small
Ragweed is 1-16 — 1-12 of an inch in length, top shaped with
prominent projecting teeth, sometimes absent, and a beak. Color
dull. Often the outer part missing and then the dark smooth

H.

seed only shows. The greater ragweed is like it but much lar-
ger. The seeds of Evening catchfly are kidney shaped about
1-18 of an inch in length, thickish and roughened, dull grayish
brown. This seed is very common in European and Eastern
grown clover seed. Several related forms have seed like it. The
Cow herb seed, however, is larger and more nearly spherical about
1-12 of an inch in diameter. Mature seeds jet black, imature
reddish, the surface is slightly roughened with minute project-
ing points. Another related seed is Corn cockle; these are about
1-10 of an inch in diameter, somewhat triangular in outline,
very rough; color, dull jet black. These seeds commonly occur
in wheat screenings. It is more or less poisonous. A number of
seeds in the mustard family are common among them; Field
mustard, Black mustard, the seeds of these are spherical about
1-18 of an inch in diameter, blackish, surface covered with a net
work of delicate ridges. The seeds have a sharp taste. The seeds
of Penny cress are somewhat egg shaped, broad in the middle,
brown, the surface has characteristic, 12-14 curved ridges, color
of seed reddish brown. The seeds of pepper grass of the same
family are small, about 1-16 of an inch in length, light reddish
yellow to brown, elongated, egg shaped, much flattened, the sur-
face is finely grooved, becomes mucilaginous when moistened.
The seeds are found in clover and in Iowa especially in timothy.
The "seeds" of Carrot are flattened, thin, about 1-8 of an inch
in length, bearing numerous spines, these are generally broken
off. Color of "seed' is whitish or yellowish. The seeds of Black
medick are similar to alfalfa, but more egg shaped than kidney
shaped, they are reddish or greenish with a smooth dull surface.
The pods are characteristic oval or kidney shaped, spirally coiled
and blackish.

The White sweet clover seed is about 1-12 of an inch long,
somewhat flattened, resembling red clover in outline, elliptical-
oblong in outline, surface smooth and dull yellowish or green-
ish. The pods often occur in commercial seed, oval in outline
1-8 of an inch long, marked with prominent veins, and beaked.
The seeds of Common vetch are spherical blackish and large.
The seeds of Cinquefoil are about 1-24 of an inch in length, straw
colored with characteristic longitudinal ridges.

Railways. — The railways scatter many different kinds of weeds.
The right of way of the railway is usually one of the best col-
lecting grounds for the botanist. Such weeds as sunflower, Buf-
falo bur, Russian thistle, gum weed, spurge, western wheat grass
are common along the trunk lines. The seeds drop from passing
trains.

Vehicles. — It has often been observed that vehicles of various

15.

kinds may be a means of scattering weed seeds. Small weed
seeds may cling to mud of wheels and be carried to some distance
away from where the seed was produced.

Threshing Machines. — Many farmers in northern Iowa where
quack grass is becoming abundant claim that the seed of this
weed, mustard, vetch, etc., is scattered by means of the threshing
machine. I have in some instances verified this claim.

Cultivation. — The "roots" of various weeds are easily scat-
tered by the cultivator. A small patch of quack grass in the
corn field may be the means of widely scattering the plant over
the field.

Packing material. — Various kinds of packing material such as
is used for packing crockery has been the source of the intro-
duction of Canada thistle, Awned Brome grass, etc. I have traced
the origin of these weeds in this way.

Wool. — The seeds of many weeds cling to the fleece of sheep
and where the wool is cleaned, and the debris thrown away these
weeds spring up. Common teasel which is used to card wool is
usually found around the woolen mill. Burdock, cocklebur, sand
bur, and hound's tongue are commonly scattered in this way.

PLANTS CULTIVATED FOR ORNAMENTAL PURPOSES.

In this state we have two conspicuous examples of weeds which
at one time were commonly cultivated for ornamental purposes
which have become troublesome weeds, namely, the toad flax and
bouncing betty. Here and there the European bindweed has
been scattered in this way. These have become troublesome weeds,
difficult to exterminate because of their perennial character. Live
forever, cypress spurge, purple pigweed and Mexican firweed are
other illustrations of weeds introduced in this way.

Plants Cultiva-ted for Food. — We have only a few weeds that
belong to this class in Iowa, but in some parts of the United
States they are more numerous. The conspicuous examples are
chicory, wild carrot, vegetable oyster plant, hemp and parsnip.

THE WEEDS OF THE IOWA WEED LAW.

The Thirty-third General Assembly passed a law making it
the duty to remove certain weeds from the public highway,
lands adjacent thereto, streets of cities and villages, right of
way of railroads and public lands.

Destruction of Weeds.
Thirty-third General Assembly of the State of Iowa.

Section 1. Land Owners or Tenants to Destroy Weeds —
When. It shall be the duty of every person, firm or corpora-
tion 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

16. __^__

mentioned in section two (2) hereof at such times in each year
and in such manner as shall prevent the said weeds from bloom-
ing or coming to maturity.

Section 2. Noxious Weeds. The following weeds are here-
by declared to be noxious weeds, namely, quack grass (Agropyron
repens), Canada thistle (Cirsium arvense), cocklebur (Xanthium
Canadense), wrild mustard (Brassica arvensis), sour or curled
dock (Rumex crispus), smooth dock (Rumex altissimus), buck-
horn or ribbed plaintain (Plantago lanceolata), wild par-
snip (Pastinacasativa), horse nettle (Solanum Carolinense), and
velvet weed or button weed (Abutilon theophrasti) and burdock
(Arctium lappa).

Section 3. Destruction on Highways — neglect or Refusal to
Destroy. It 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 un-
necessary brush on the highways in such a manner as to effec-
tually prevent the production of their seeds or their propaga-
tion in any other manner, to warn out labor or to employ labor
for this purpose in the same manner as for repairs to the high-
ways, 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 de-
stroy 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 pub-
lic highway, or upon complaint of any land owner to the town-
ship trustees that his lands have been or are likely to be infested
by weeds from the lands of another including railway right of
way, the trustees shall make investigation of such condition or
complaint and if the same appears 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 destruction 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 pre-
vented from maturing seeds or may cause such noxious weeds to
be permanently destroyed and the cost of the work shall be re-
covered 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

17.

is hereby made a part of the road work of the township trus-
tees 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 in-
serting after the comma in the eighth line thereof the following
words: "and for the destruction of noxious weeds in public

Russian Thistle, a — mature plant; b— seedling, about two weeks after
germination, natural size ; c — flower hanging from the axil and remaining
suspended by minute hairs in the ordinary inverted position of a rolling plant
enlarged 3 diameters ; d — flower viewed from above and in front, showing
the calyx lobes forming a cone-shaped body, and the large membranaceous
spreading wings, enlarged 3 diameters ; e — seed, with flower part removed ;
enlarged 5 diameters ; f — embryo removed from seed, enlarged 7 diameters.
(U. S. Dept. of Agr., Bull No. 15.)

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.

18.

Section 6. School of Instruction. Between November and
the succeeding April of each year the county supervisors shall
call a meeting of the township trustees and the road supervisors
of the county to consider the best methods of weed extermina-
tion and road building, secure services of experts to give in-
struction in road building and weed destruction. For such at-
iendance 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 li i^hways. It shall be the
duty of the township trustees and other officers directly respon-
sible for the care of public highways to cause to be cut near the

Lamb's Quarter. Goosefoot (Chenopodium album). A branch with den-
tate leaves and inflorescence. 1 — flower with calyx, 2 — seed. (U. S. Dept.
Agr.)

surface all weeds on the public highways in their respective dis-
tricts at such times and in such manner as to prevent seeds from

19.

nurturing.

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 and sixty-two-a
(1562-a) and fifteen hundred and sixty -three (1563) of the sup-
plement to the code, 1907, and sections fifteen hundred and six-
ty-four (1564) and fifteen hundred and sixty-five (1565) of the
sode are hereby repealed.

Approved April 21, A. D., 1909.

OTHER WEEDS.

This list does not include by any means all of the injurious
weeds, but some of the worst. In some parts of the state some
weeds are more injurious than others. Quack grass is more im-
portant in northern Iowa than in southern. The horse nettle
is most troublesome in southern Iowa ; cocklebur is troublesome
in all parts of the state. The velvet weed, the smooth dock,
curly dock, and burdock are widely distributed.

TREATMENT OP WEEDS.

Weeds in order to be eradicated need various treatment. The
annual and biennial are not so difficult to exterminate as the per-
ennial. The first and most important consideration is clean cul-
tivation. In nearly every case this will destroy the annual weeds.
The land for corn should be plowed in the fall. The good farmer
will practice rotation of crops. If he uses the following rota-
tion : oats, clover and corn, the clover field can be plowed under
after the removal of the crop. The land will be reasonably clean,
because the cloevr is an excellent plant to keep many weeds down,
especially if the growth is rank. In the spring the field should be
disced, and the seedlings of many young plants will be destroyed.
The corn field should then be given clean cultivation.

It is common practice in Iowa to sow oats directly on the corn
stubble, simply discing. This is bad practice. It would be far
better if the corn could be cut and the stalks used for fodder,
the field plowed in the fall and the oats sown in a clean field.
Usually the corn fields are so weedy in Iowa that it is difficult
to get a clean field of oats. The time is coming when the Iowa
farmer will cultivate his fields more thoroughly.

Clover can be sown with oats, if the stand is even the ground
will be pretty well covered the next season. In Iowa clover is
usually treated as a biennial. This allows two years for a clover

20.

crop. The above treatment can only be recommended for an-
nuals. Many of the seeds of weeds will germinate but some will
keep their vitality for some years as sweet clover and Indian
mallow or butter print. The seeds of both weeds are known to
keep their vitality for more than half a century.
Perennial Weeds. — The above methods will only partially destroy
the perennial weeds. Quack grass, Canada thistle, and weeds
of this character need special treatment. If the leaves of these
perennial weeds are prevented from growing the weed will be
killed in the course of time, they will starve usually, however, in
ordinary methods of cultivation, but some plants are not noticed
and these give rise to new plants. Let me give a few weeds with
specific treatment.

Quack Grass (Agropyron repens). Creeping rootstocks and a number of
stems (culms), a spikelet at a., each containing a number of flowers, o — a
spikelet with sterile glumes at 2 and flowers above.

21.

TREATMENT FOR A PEW SPECIAL WEEDS.

Quack Grass. — This is the most difficult weed to exterminate in
Iowa. There is no easy method. It can be removed by giving
the field a shallow plowing, in the summer follow with a harrow,
bringing the roots to the surface and continue discing and har-
rowing until most of the "roots" are destroyed. Late summer
and fall is the time to do this. The next season this may be
followed with a crop of sorghum sown very thickly. This will
probably remove most of the quack grass, but not all. Hemp
may be sown in place of sorghum. Dewey claims that several
fields where quack grass was abundant, the hemp plant has ma-
terially held the quack grass in check. The pasture method has
been recommended by Prof. Spillman and what I have seen in
Iowa would lead me to believe that it is an excellent method.
The field containing quack grass is put in meadow and pastured
for two or three years in this way. This method causes the
roots to come to the surface. They spread less freely in the
meadow than in cultivated ground. The soil is plowed two to
three inches deep in the summer, then harrowed two or three
times to bring the "roots" to the surface; these may then be
removed from the soil and burned. If the season is favorable, that
is dry, two or three harrowings will accomplish the killing, but if
wet some "roots" will keep alive and it may be necessary to plow,
say not less than six inches. After this has been done two or three
times the land will be nearly free from quack grass. The field
should be watched and when quack grass appears, it may be re-
moved by digging up and hoeing. Deep plowing will also destroy
the roots, but this can seldom be done well and some "roots"
are to be seen near the surface which will develop new plants.
The roots of quack grass are shallow rooted.

The Cover Method. — The cover method can be applied when
the patch is a small one. For this use tarred paper overlapping
the edges. Leave the paper on the quack grass for six months.
A heavy coating of straw, six inches to one foot, will also be
serviceable, this brings the roots to the surface where they can be
raked off and burned; then plow, harrow and cultivate.

Canada Thistle and Horse Nettle. — These weeds are deep rooted
and in order to destroy them it will be necessary to plow the
field, follow with a harrow two or three times and keep the field
clean for the rest of the season. The work should be done in
midsummer; if all of the plants cannot be reached by the har-
row it may be necessary to cut the plant off with a hoe. Sodium
arsenite and iron sulphate may also be used. It is sometimes ad-
visable if the patch of thistle occurs in a field to get it in pasture
and place a lot of salt around the Canada thistle. Stock will

22.

then destroy the weed.

Morning Glory and Milk Weed. — Morning glory and milk weed
can best be kept down by thorough and continued cultivation. If
a field is badly infested with morning glory it is best to get it
into pasture, allowing hogs and sheep to pasture closely. The
cultivation method according Cox used in some places is as fol-
lows :

"Several methods for accomplishing this eradication have been
successful. Clean cultivation is one of the best in many cases.
It is essential to employ such implements as will keep down the

Wild Morning Glory (Convolvulus scpium). Two large bracts at the base
of each flower. A common troublesome weed In fields, meadows and waste
places. (U. S. Dept. Agr.)

top growth successfully. Where the weed occurs in patches these
should be marked oft' arid given special attention.

"The bindweed may be greatly reduced or entirely destroyed

23.

by seeding the land to alfalfa. The frequent cutting and the
shading effect of this crop are the determining factors. Alfalfa
should be followed by a cultivated crop to complete the work of
destruction.

"Pasturing with hogs has been successful in killing bindweed,
since hogs are quite fond of the underground parts. This me-
thod can be used with both ordinary pasture and fallow land.
Results can probably be obtained in less time in the latter case."

Indian Mallow. — This weed is an annual. It is not difficult to
exterminate, cultivation will destroy it. The great difficulty
with this weed and the Shoo fly is that the seeds retain their
vitality for many years. There are cases on record where a per-
centage of the seeds of Indian mallow germinated after the lapse

Greater Ragweed or King Head (Ambrosia triflda). Sometimes called
Horseweed. Upper p:irt of a branch, staminate flowers above, pistillate
flowers just above the leaves, n — a so-called seed more properly an Involucre

with a bract on the right hand
Agr.)

Ida,

-with bracts removed. U. S. Dept.

24.

of half a century. No matter how much cultivation you give
the soil a new crop of weeds will appear.

Sweet Clover. — This biennial weed is common in many parts of
the state. It produces a tap root which is not difficult to exter-
minate by cultivation. As in the preceding case the seeds retain
their vitality a long time.

Greater Ragweed or Kinghxad. — This weed is a troublesome
pest in many Iowa fields along fences and railroads. The plants
are easily destroyed in fields by cultivation. The seed probably
retains its vitality for some time. Iron sulphate, 100 pounds
to a barrel of water will destroy it. Plant clean seed.

Nimble Will or Drop-Seed Grass. — This station has received
many letters complaining about this weed. The character of the
"roots" is so different from that of the roots of quack grass and
the other perennial weeds that we have mentioned before 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 this weed we found that by giving a
shallow plowing of four or five inches and harrowing to expose
the roots to the sun, they were killed, no growth making its ap-
pearance during the rest of the season. Of course this is not
effective during rainy weather.

Cocklebur. — The cocklebur is a serious menace to cultivated
crops in many parts of the state, more especially in southern
Iowa. The best method of combating the cocklebur is the rota-
tion of crops and clean culture. When 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 cultiva-
tor, 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 pos-
sible turn it into pasture. This certainly eradicated the cockle-
bur, ragweed and many other annual weeds.

Summer Fallow. — Undoubtedly this is a splendid method for
the eradication of weeds. I am not using the term, however, as
it is ordinarily used. To plow and then leave fallow for the
summer, but constant cultivation and harrowing must be resorted
to in order to remove the weed. The field must be kept free from
weeds during the summer and fall.

The Use of Chemicals. — In recent years many experiments have
been made with various chemicals to destroy weeds. Among
them iron sulphate, sodium arsenite, corrosive sublimate, copper
sulphate and common salt.

Some of these substances like sodium arsenite and corrosive

25.

sublimate are strong poisons. The copper sulphate is also poison-
ous but less so than the other solutions. Sodium arsenite will de-
stroy Canada thistle and many other weeds. It may be used
at the rate of l1/^ pounds to 52 gallons of water. Stock must
be kept away when the thistles are treated. The treatment must
be repeated as often as thistles appear. Corrosive sublimate was
found to be efficient in killing many weeds, but is not to be recom-
mended on account of its very poisonous nature. Salt, when ap-
plied in sufficient amount is efficacious, but it is expensive when
used in this way and can only be used as I have indicated for
Canada thistle and Horse nettle. Iron sulphate, which is a by-
product in the manufacture of wire is cheap, costing in 100 pound
bags, 92 cents per hundred pounds F. O. B. from several Iowa
points. If bought in 200 pound bags it costs 5 cents less per
hundred pounds. It comes in granulated form, is readily soluble
in water and may be made in various strengths of solution. For
most plants it is used at the rate of 100 pounds to a barrel of
water. The solution cannot stand over night. It may be applied
with a hand or traction sprayer. I have found it efficacious for
the following plants: Mustard, ragweed or kinghead, smart-
weed, dandelion, artichoke, velvet weed, small ragweed, lamb's
quarter, may weed, hedge mustard, pigweed, boot jack, etc. In
fact the majority of weeds found in grain fields readily yield to
the application of this spray.

WEEDS OF SPECIAL CROPS.

Small Grain. — It is well known that certain weeds occur with
certain crops since the very earliest times ; such weeds as common
mustard, darnel, corncockle, vetch and bindweed or wild buck-
wheat have been found with small grain. These weeds are as
common in Europe as in the United States. They are found
wherever small grain is cultivated. Formerly it was difficult to
remove these weed seeds from the grain, but with modern me-
thods of screening has made it possible to remove most of the
weed seeds.

Corn. — Locality sometimes determines the kind of weeds found
in the field; in southern Iowa cocklebur, horse nettle, arc com-
mon. In northern Iowa quack grass and artichoke occurs. The
smartweeds, fox tail pigeon grass, crab grass, shoestring, milk-
weed, pigweed and morning glory are common in all parts of
the state. In early spring northern nut grass may appear;
easily recognized by the yellowish appearance of the field. The
plant has grass-like leaves and spreads by its "roots." Rag-
weeds are also common in all parts of the state; velvet weed is
common and in western Iowa marsh elder and sunflower are
abundant.

Garden Weeds. — The most common garden weeds are purslane,
pigweed, lamb 's quarter, crab grass, nimble will, fox tail, spurge,
boot jack, smartweed, speedwell, horse weed, etc., are quite uni-
versal in the state.

Meadows. — The more important weeds in clover meadows are
curled and smooth dock, fox tail, nimble will, horse weed, pep-
per grass and smartweed, yarrow, pigeon grass and small rag-
weed. The buckhorn, bracted plantain, chicory, carrot, white
catchfly, evening catchfly, black medick and yellow clover are
occasional and of recent introduction.

Pastures. — In Iowa pastures the hoary vervain with blue flow-
ers in long spikes. Small ragweed, pigeon grass, fox tail and
golden rod are the most conspicuous weed in all parts of the
state.

Roadsides. — The weeds of the roadside are generally much the
same as those occuring in adjacent fields. In eastern Iowa dog
fennel or may weed, yellow clover and jimson weed. The fol-
lowing are general in the state: Small ragweed, greater rag-
weed, horse weed, pitch forks, golden rod, morning glory, par-
snip, milk weed. In western Iowa marshelder, sun flower, stink
weed, fetid marigold are among the most important weeds.

J'oisonons Weeds. — The laity should become more familiar
with the poisonuos plants of the state. There are a great many
plants which are more or less poisonous to man and lower ani-
mals, a few are, however, deadly poisonous. Some of these dead-
ly poisonous plants are found in all parts of the state. The
most poisonous of these is the cowbane which occurs in low
grounds, has white flowers occurring in umbels, leaves divided,
fleshy roots, clustered, of a pungent odor and taste. The roots
are deadly poisonous, a small amount not larger than a hazel
nut taken in the fall, winter or spring has caused death to a
boy. In the year 1909 near Boone two boys were poisoned.
One lad a high school boy picked up some of the roots which
were turned over by a farmer while breaking a meadow. The
boy was carried to a farm house in the neighborhood and a
call sent for a doctor. The doctor made a rapid trip to the
house in his automobile, taking the boy, but when the hospital
was reached he died. The second boy died under somewhat dif-
ferent circumstances. This boy later evidently picked up some
of the plant to show the doctors Avhat his companion had eaten
and later he developed symptoms resembling those found in
poison ivy poisoning. Similar cases have been reported else-
where. Some persons who pull up the plant get eruptions on the
skin. I am told that the same thing occurs when persons pull
or come in contact with the leaves of the cultivated parsnip

27.

riming wild. This plant has yellow flowers and a straight tap
root. The root so far as I know is not poisonous at least I am a
witness to the fact that the root of the wild plant is not poison-
ous since I have eaten it. Jimson weed is another poisonous
plant. The plant is narcotic and has a pungent odor. It has
large white flowers leaves and a spiny "pod" (capsule) with
numerous blackish seeds. These seeds are very poisonous. Poison
ivy is another poisonous plant of the state which is not generally
recognized by the laity. It is often mistaken for Virginia
creeper, but is readily distinguished by the three leaves — the Vir-
ginia creeper having five — the leaves of the poison ivy are also
wider. The poison ivy plant may grow erect or creeping over
bushes and up trees. The berries are white, while those of the
Virginia creeper are blue. Poison hemlock is another poison-

Cowbane (Cicuta maculata). Common in low ground; flowers white, stem
hollow, fasciled, fleshy roots, "seed" fruit to the right; cross section lower
left hand corner. (U. S. Dept. Agr.)

ous plant in the state, as yet not common it belongs to the
same family as the cowbane and parsnip. The plant has a rank;
smell something like mice. The flowers are white, small in urn-

28.

bels. This is the plant that Socrates used to kill himself. Of
the other poisonous plants I may mention the seed of castor oil ;
the bark of black locust, the flowering spurge with milky juice,
the cultivated poppy, mandrake or may apple sneezcweed with
yellow flowers found in marshes. Wilting sorghum is poisonous
to stock. The leaves of black cherry and the seeds of plum and
cherry are poisonous. The so-called mushroom should be avoided
at all times, especially such as are brilliantly colored. We have
several deadly poisonous species in Iowa. While there are many
edible ones, unless you are familiar with them, they had better
be left alone.

WHAT TO DO IN CASE OF POISONING.

As soon as possible use an emetic to produce vomiting, use
tartar emetic; salt and gruel may be given, follow by infusions
of hot coffee and epson salts. In case of poison ivy poisoning
wash with soap immediately and follow with acetate of lead.

29.

APPENDIX.

Descriptions of a Few Weeds Especially of the Iowa Weed Law.

GRASS FAMILY — ( Gramineae. )

We have a large number of weedy plants in this family. In
addition to those mentioned above, atiention may be called to
the sandbur, sprouting crab grass, crowfoot grass, Johnson grass,
chess or cheat, etc. Mention may also be made of the fact that
wheat, rye, barley, oats and corn belong to the same family.

Foxtail or Piegon Grass (Setaria glauca). Annual root, a — sheath and
part of leaf, b — a spikelet with bristles and glumes and cross striated "seed".
c-d-e-f — other views of the flower, f showing stamens and stigmas exserted ;
pistil and stamens enclosed by the palea. (Charlotte .M. King.)

YELLOW FOXTAIL — (Setaria glauca (L.) Beauv.)
An erect annual one to two and one-half feet high, flat leaves
bristly cylindrical spike, from one to three inches long. The
heads are slender and the bristles tawny yellow. The small seeds

30.

of this species are conspicuously cross striated and are easily dis-
tinguished from the next species because of its larger size and by
it cross striation. This species also comes up in grain fields after
harvest, hence seeding the soil abundantly.

GREEN FOXTAIL — (Sctario, mridis (L) Beauv.)
An erect annual from one to three feet high, leaves four to
twelve inches long with rough margins, greenish, more or less
compound cylindrical spikes from one to five inches long or even
in some cases six. Bristles few, much longer than the spikelets.
Spikelets one-twelfth of an inch long, the chaff (second and third
glumes) as long as the minute chaff (fourth glume), the latter
being dotted and striate. A single head produces an enormous
number of seeds. "When fields are sown to oats this plant comes
up in the fall and late summer Deeding the soil.

Quack grass with a head somewhat more enlarged. (U. S. Dept. Agr.)

QUACK GRASS — (Agropyron repens (L.) Beauv.)
A perennial with widely spreading but shallow rootstocks which

31.

form dense mats. Flowering stems numerous, smooth, flowers
in spikes; leaves from 4 to 12 inches long, smooth or sometimes
pubescent; spike 3 to 10 inches long; the separate parts of the
spikes are spoken of as spikelets, these contain from 4 to 8 flow-
ers. The chaffy scales of the spikelets are spoken of as the empty
glumes. Each flower has a flowering glume and a palet; each
flower contains stamens and pistils.

This plant, quack grass, is closely related to western wheat
grass which may be readily distinguished by the glaucus green

Squirrel Tall Grass, Wild Barley (Hordeum jubatum). Winter annual
or annual, a — part of stem, b — portion of spike showing the sterile and fertile
flowers and the long awned glumes, c — single flower with long awned glume.
A troublesome weed everywhere in the state. (Charlotte M. King.)

Drop Seed Grass or Wild Timothy (Muhlenbergia racemosa). I single
spikelet to the right. Stalk with roots (rootstock) clustered.

color which forms a decided contrast to the ordinary green of
blue grass or other grasses in this state. The spikelets, too, are
denser and thicker. This grass is commonly found along rail-

32.

ways. Slender wheat grass (Agropyron tenerum) has slender
spikes from 4 to 8 inches long; the numerous rootstocks are ab-
sent. Quack grass is frequently mistaken for drop seed grass
(Muhlenbergia mexicana) but this may be readily distinguished
from quack grass by its clustered thick and short rootstocks and
for this reason sometimes it is called the turkey foot grass. The
spikes containing the seed are slender. The empty glumes are
nearly equal.

Crab grasses. Left hand figure common Crab grass (PANICUM SANGUINALE) ; right
hand figure Smooth Crab grass (PANICUM GLABRUM).

SQUIRRELTAIL GRASS — (Hordeum jubatum L.)
An annual or winter annual from six inches to two feet high
producing fibrous roots. It forms solid and compact bunches.
Leaves not unlike those of blue grass, but paler in color, from
two to four inches in length, margins scabrous. Flowers in a
dense spike from two to four inches long, pale green or purplish
in color. The spike consists of a number of one-flowered spike-

33.

lets, three occurring at each joint, only one is perfect (bearing
stamens and pistil). The two other spikelets are awl-shaped
and rudimentary; these are borne on short stalks. One of these
sterile spikelets occurs on each side of the perfect flower which
bears a long awn. At each joint will be found six empty long-
awned glumes spreading at maturity. These give to the plant
the bristly appearance at maturity. When mature the spike
breaks up into joints consisting of the rudimentary spikelets and
a perfect flower, so that each joint has one "seed." The num-
ber of "seeds" in a spike varies from thirty-five to sixty. A
single cluster of plants may therefore produce from three hun-
dred to two thousand mature "seeds." The plant has a won-
derful capacity for "stooling. " From a single plant as many
as forty spikes may be produced, and the number no doubt often
exceeds this.

CRAB GRASS — (Panicum sanguinale L.}

A much branched, leafy annual one to three feet high, spread-
ing on the ground, with erect, smooth, spreading culms, frequent-
ly rooting at the lower joints. Joints smooth, though more fre-
quently bearded with de'flexed hairs. Sheaths loose, generally
pilose ; hairy, ciliate on the margins, with a membranaceous ligule.
Leaves two to four inches long with rough margins, occasionally
pilose at the base. Flowers produced in digitate spikes hence the
common name finger grass is sometimes given it. Spikelets less
than one-eighth of an inch long in pairs, one nearly sessile the
other with a stalk. Each flower consisting of two sterile glumes
(chaff) and the flower proper. The first bract very small, the
second about one-half to two-thirds as long as the spikelets, us-
ually hairy on the margin. The third glume somewhat longer
than the fourth which is five nerved and usually silky-villous
along the marginal nerves. Fourth glume smooth and acute.
The fruit is minute, pitted and cross striated, light straw color
except Avhere the sterile glumes remain attached. These are gray
in color and minutely hairy.

SEDGE FAMILY — (Cyperaceae.)

Of the Sedge Family the most important weed in the state is
the northern nut grass (Cyperus esculentus) ; this plant is read-
ily recognized by the yellowish cast of the corn field in the
spring and the little plant has corms or bulbs, and with roots
which enables it to spread.

DOCK AND SMARTWEED FAMILY — (Polygonaceae.)

This family also contains a large number of important weeds
many of them are very troublesome to our crops. Mention may
be made of smartweed, tanweed or devil's shoestring, sheep sor-
rel or horse sorrel, all common weeds in this state.

34.

CURLED DOCK — (Eumcx crispus L.)

This weed is a smooth perennial from three to four feet high,
leaves with strongly wavy and curled margins, lanceolate and
acute. In the lower leaves the bases somewhat truncate or in-
clined to be heart shaped. The flowers are collected in dense

Curled Dock (Ramex crispus) in clover meadows and along roadsides. A
common European weed. (U. S. Dept. of Agr.)

whorls, extended or prolonged into racemes, entirely leafless
above, but below with small leaves. The flower consists of six
sepals, the outer herbaceous, leaflike, the three inner larger and
somewhat curled, and after flowering forming the valves of the
fruit. These surround the three angled fruit (achene) all the
valves bearing a grain.

35.

PEACH-LEAVED DOCK OR PALE DOCK — (RumCX dltissimUS Wood).

A tall perennial with multiple roots; leaves oval, oblong, lan-
ceolate extending into a point, pale and thickish; the 'flowers in
spike-like racemes or panicles, flowers with nodding pedicels, the
valves of the flower are obscurely heart-shaped; commonly with
a conspicuous inflated grain. Common in alluvial soil every-
where in the state.

SHEEP SORREL — (Rumex dcetoselld L.)

A low smooth annual or perennial, usually the latter, growing
from six to twelve inches high ; producing an erect stem ,with
horizontal, creeping, woody rootstock or rhizome ; petioled, nar-

Sheep sorrel (RCMEX ACETOSELLA) .
Dept. Agr.)

1 staminate flower; b. pistillate flower. (U. S.

rowly hastate, narrow, lanceolate leaves, the upper linear ; flow-
ers on jointed pedicels ; dioecious small in a terminal naked pan-
icle ; small green calyx; exserted stamens; the valves (inner calyx

36.

lobe) not enlarging in fruit.

GOOSEFOOT FAMILY — (Ckenopodiaceae.)

This family contains a number of common and troublesome
weeds, among them the common lamb's quarter or goosefoot
(Chenopodium album), a weed commonly found in gardens and
along roadsides. Spinage also belongs to this family.

PIGWEED FAMILY — (Amaranthaceae.)

This family contains a number of troublesome weeds, in this
state one of the most common being the common pigweed (Amar-
anthus retroflexus) , and the common Iowa tumble weed (A.
graecizans. )

PINK FAMILY — (Caryophyllaceae.}

Of the Aveeds of this family mention may be made of the cow
Lerb, common in grain fields, the evening catchfly, wakerobin,

Corn Cockle (Agrostemma Githago). A hairy plant with purple flowers.
The long outer segments are lobes pf the calyx, 2 — capsule with calyx and
seeds, 3 — kidney-shaped seed. (U. S. Dept. Agr.)

37.

etc. The carnation belongs to the same family.

CORN COCKLE — (Agrostemma Githago L.)
A hairy annual weed, clothed with long, soft hairs. Leaves
linear-lancoolate, acute or long acuminate; flowers purple and
long peduncled; calyx lobes long, linear, surpassing the purple
red petals; seeds large, roughened and black.

ITKSLAXE FAMILY — (Portiilacaccae.)

This family contains but one common weed, the common pusley
or purslane (Portulaca aleracea) which is common in gardens

Purslane (P°rtulaca oleracea). General view of plant to the right. 1 —
flower in cross section, pistil in center with ovules attached, stigmas above,
stamens to the right and left, 2 — A capsule with a line in the middle where
the capsule splits. 3 — The same with top of capsule removed showing the
seeds. 4 — Seed. 5-6 — Stamens. (U. S. Dept. Agr.)

everywhere in the state, and the common moss rose of Peru is
cultivated.

38.

Charlock or Mustard (Brassica arvensis). A common weed in grainflelds
ind waste places. (U. S. Dept. Agr.)

CROWFOOT FAMILY — (Ranunciilaceae. )

.V number of weeds are members of this family, among them
the common crowfoot with a sharp acrid taste (Ranunculus
abortivus] ; also such cultivated ornamental plants as the peony,
larkspur, aconite, columbine and clematis. Many of these plants
are poisonous. .

MUSTARD FAMILY — ( Cru tiferae. )
Among: the common weeds not described below mention may

Butter Print or Indian Mallow (Abutilon theophrasti) . A velvety pubes-
cent annual, flowers ami capsule , e ach division with several seeds. (U. S.
Dept. Agr.)

be made of the tumbling mustard, pepper grass (Lepidium
apctalum), common everywhere in the state. Cabbage, turnip
and rutabaga, and mustard belong to the same family.
MUSTARD OF ENGLISH CHARLOCK — (Brassica arvensis (L.) Ktze.)
Lower leaves nearly divided to the middle, with the divisions
unequal, the terminal lobe larger. Upper leaves sessile much

40.

smaller than the lower. Flowers yellow, large and very fragrant.
Pods one to two inches long, irregular in outline, appearing
somewhat nodose, three to seven seeded or more occasionally.
The upper part of pod forms the beak. Seeds round, brownish
black, darker than in B. nigra and minutely pitted. The pods
of black mustard shorter and angled. Seeds of all of the mus-
tards mucilaginous. There are many other mustards in the state
like hedge mustard, pepper grass, etc.

Wild Carrot (Daucus Carota). Common in the East in clover meadows
and introduced into this state with clover seed. A bristly hairy biennial. 1
— general view, 2 — flower with stamens, pistil, corolla, 3 — fruit. (U. S. Dept.
Agr.)

MALLOW FAMILY — (Malvaceae.)

A number of very common weeds in this state belong to this
family, among them the common cheeses, and crisp mallow, also
such ornamental plants as the hollyhock.

, 4L

BUTTER PRINT OR VELVET WEED — (Abutilon Theophrasti Medic.)
A tall annual from two or four feet high; leaves roundish
heart-shaped and velvety, pubescent, taper pointed, pedicels
shorter than the leafstalk ; flowers small with yellow corolla ; pod
consisting of 12 to 15 beaked carpels which are pubescent. Com-
mon in waste places and vacant lots. Seeds preserve their vital-
ity for a long time.

Field Dodder (Cuscuta arvensis). Found on clover. a — flower; b —
flower spread apart ; c — capsule with stamens and styles therein ; d — seed.
(Dewey Division of Botany, U. S. Dept. Agr.)

Alfalfa Dodder (Cuscuta epithymum). a — flower; b — flower spread apart
to show stamens and corolla ; c — capsule showing styles ; d — seed. (U. S.
Dept. Agr.)

PARSELY FAMILY — (Umlellifcrae.)

This family contains a number of weeds some of them most
troublesome. In addition to those described below mention
may be made of the poison hemlock (Conium maculatum}, some
of the cultivated plants are the carrot, parsley, lovage and dill.

42.

This family contains some of the most poisonous plants in the
vegetable kingdom, like the cowbane or water hemlock and poison
hemlock.

PARSNIP — (Pastinaca sativa L.)

A biennial with grooved stems; pinnately compound leaves,
with ovate to oblong cut toothed leaflets. Fruit oval to flattened
with broad wings. This tall stout glabrous or somewhat pubes-
cent biennial is as escape from cultivation. It has a straight tap
root in place of multiple thick fleshy roots as the poisonous hem-
lock or cowbane frequently called parsnip in this state.

Horse Nettle (Solanum carolinense) , a perennial weed troublesome in
southern Iowa. Potato-like flowers and prickly stem (Division of Bot.,
U. Dept. Agr.)

Buckhorn (Plantago lanceolata). With a timothy-like head and elongated
leaves. Common in clover meadows. (Charlotte M. King.)

CARRROT — (Dau-cuK Carota L.)
A biennial or annual with bristly stems and pinuately decom-

43.

pound leaves; bracts surrounding the flowers leaf -like; white
flowers in umbels becoming concave. This plant with a straight
tap root has been widely distributed with clover and alfalfa. It
is one of the most pernicious weeds of the eastern meadows.

Bull thistle (Cirsium lanceolatum). A troublesome biennial weed common
in woods, pastures and along roadsides. (U. S. Dept. Agr.)

COWBANE. WATER HEMLOCK — (ClCUta maculatd L.)

It is a smooth marsh perennial two to five feet high with pin-
nately compound leaves two or three times pinnate; the leaves
have long petioles, the coarsely serrate leaflets are lanceolate to
oblong lanceolate one-fifth inch long. Stalks of the umbellets
numerous and unequal. Flowers white, fruit broadly ovate to
oval, small one and one-half inches long. Grows in marshes
and in low grounds. The stems spring from thick fleshy under-
ground roots that taper at the lower end. These usually number
from three to five, but single specimens are also met with. On

44.

cutting the roots a sharp pungent odor is given off.

MORNING GLORY FAMILY — (ConVOlvuldCeae.)

In addition to the weeds described below, we have the Euro
pean bindweed or morning glory, the southern morning glory
(Ipomoea purpurea) and related species. The sweet potato be-
longs to this family.

Canada thistle (.Cirsium arvcnse). A common troublesome weed in gar-
dens, roadsides and sometimes in clover fields. Notice the perennial roots at
2, and the flowers at 3. (U. S. Dept Agr.)

DODDER — ( CllSCUttt Spp. )

The dodders are leafless excepting the small scales on the
stems, herbs of reddish or yellowish color, with thread-like stems
twining around the plants upon which they live. They pierce
the plant with small and short rootlets which are called suckers
or haustoria. The seeds are small, yet there is stored sufficient
nourishment in them to give the embryo a start. The seed ger-

.45

minates in the soil and grows sufficient in length to allow it to
come in contact with the plant upon which it lives, when it im-
mediately sends in its suckers, and thus becomes established upon
the plant as though it were a part of the host.

The dodders contain no chlorophyll, the green coloring matter
iound in leaves, and hence cannot make food, that is, make starch
out of raw material such as ordinary green leaves do, but must
derive nourishment entirely from the host upon which they live.
Such plants are called parasitic.

Cockle Bur (Xanthium canadense.)
(U. S'. Dept. Agr.)

Weed of cornfields and roadsides.

We have two troublesome dodders in this state, the clover dod-
der (Cuscuta epithymum Murr.) on alfalfa and clover, with
slender stem with elongated stigmas and field dodder (C. arven-
sis) with capitate stigmas.

HEDGE BINDWEED OB MORNING GLORY — (Convolvulus septum L.)

47.

NIGHTSHADE FAMILY — ( Solanctceae. )

This family contains a number of very troublesome and per-
nicious weeds, among them the common black nightshade (Sola-
num nigrum] with small white flowers, the Buffalo bur (S. ros-
tratum) with prickly stems and fruit and yellow flowers, leav.es
resembling those of the water melon; the ground cherry (Phy-
salis), the Jimson weed, two types, both species poisonous. Of
the cultivated plants it contains the potato, tomato and tobacco.

Burdock (Arctium
gardens and pastures.

Lappa). A common biennial weed
(Divi

waste places,

ision of Bot., U. S. Dept. Agr.)

HORSE NETTLE — (Solanum carolmense L.)
Horse nettle is a deep-rooting perennial, propagating freely
by its underground roots, these running roots are often three
feet long; stem from one to two feet high, somewhat straggling,
half shrubby at the base ; stem hairy or merely roughish with
minute hairs which are star-shaped, also armed with stout subu-

46.

Smooth, occasionally, however, pubescent, twining around sup-
ports or trailing. Leaves triangular, halberd or arrow-shaped,
the tip acute, or pointed, the basal lobes obliquely truncate or
sinuate lobed. The flowering peduncles four angled with two
leaf -like bracts which are commonly acute. Corolla is white or
tinged with rose purple.

Small Ragweed (.Ambrosia artemisiaetolia) . With deeply divided leaves
and branches with flowers. 1 — head with staminate flowers, 2 — pistillate
flower containing the "seed." (U. S. Dept. Agr.)

MINT FAMILY — (Labiatae.}

A number of troublesome weeds like the catnip, common ger-
mander or wood sage, and peppermint, with creeping " roots"; of
the cultivated species the scarlet sage, peppermint, hyssop, etc.
Many of the plants have a pungent flavor, and square stem, and
thus are easily recognized.

48.

late yellowish prickles which are usually numerous ; leaves oblong
or sometimes ovate, obtusely sinuate, toothed or lobed or deeply
cut, two or four inches long. The flowers are borne in what are
called racemes, which later become one-sided; the outer part of
the flowers, the calyx, consist of slender lobes, the corolla is light
blue or white, an inch or less in diameter. The flowers are fol-
lowed by the yellow globose berries, half to three quarters of an
inch in diameter. The seeds are yellowish, a little less than one-
twelfth of an inch long, minutely roughened. The flowers re-
semble those of the common potato, and are blue or white, an
inch or less in diameter. The yellow berries also resemble those
of the potato. The spiny character of the leaves and the further
resemblance of the flower to the potato should render it easy of
detection.

PLANTAIN FAMILY — ( Plant aginaceac. )

Of the plantains the most common weed not described is the
common dooryard plantain of which there are two kinds, Plan-
logo major and P. Kugelii; the bracted plantain is becoming a
troublesome weed in the southern part of the state, especially in
clover fields. This plant is something like the common plantain
but the leaves are narower and the heads with large bracts.
BUCKHORN — (Plaoitago lanceolata L.)

A perennial or biennial, pubescent, with short erect root-stocks ;
leaves narrowly oblong lanceolata ,somewhat shorter than the
scape, three to five ribbed ; scapes slender with spikes dense, at
first capitate, later becoming cylindrical ; bracts and sepals scari-
ious, brownish; calyx of four persistent sepals and glabrous co-
rolla. Two small smooth brownish seeds found in each vessel.
COMPOSITE FAMILY — ( Compositae. )

The Composite or Suriflower Family is a large family of plants
containing some of the most troublesome of our weeds. The fam-
ily gets its name from the common sunflower which is wreedy in
the western part of the state, but in addition there are a large
number of other weeds of this family like the dandelion, May
weed, sneeze weed, marsh elder, troublesome in western Iowa,
the leaf looks something like the sunflower, but the flowers are
like the common ragweed, tansy, and so on. Of the cultivated
plants attention may be called to the lettuce and chicory. Sneeze
weed with yellow flowers growing in low ground is poisonous.
Aster, golden rod, horse weed and dandelion belong to this fam-
ily.

BULL THISTLE — (Cirsium lanceolatum Willd.}

A branching biennial, three to four feet high, tomentose, be-
coming dark green and villous or hirsute with age, branchlets
bearing large heads ; leaves lanceolate, decurrent on the stem with

49.

prickly wings deeply pinnatifid, the lobes with rigid prickly
points, upper face roughened with short hairs, lower face with
a cottony tementum ; heads one and three quarters to two inches
high, bracts of the involucre lanceolate, rigid when young, more
flexible with age, long attenuated prickly pointed spreading tips,
arachnoid woolly; flower hermaphrodite, tube of the corolla ten
lies long, anther tips acute, filaments pubescent, achenes smooth,
one and a half inches long, pappus of numerous plumose bristles.
CANADA THISTLE — (Cirsium arvense (L.) Scop.)

A smooth perennial, spreading by creeping roots and root-
stocks, one to three feet high, corymbosely branched at the top ;
stem smooth; leaves lanceolate, sessile, and deeply pinnatifid,
lobes and margins of leaf with spiny teeth ; heads small, three-
fourths to an inch high, bracts appressed, the outer with a broad
base, inner narrow, all with an acute, never spiny tip ; flowers
purple, dioecious, one plant with stamens and the other with
pistils. Common in many parts of the state.

COCKLE BUR — (Xanthium canadense Mill.)

A course, rough annual from one to three feet high, stem
marked with brown punctate spots; leaves alternate, cordate or
ovate, three nerved, long petioled. Flowers monoecious, stamin-
nate and pistillate flowers in different heads, the pistillate clus-
tered below. The involucre of the staminate flowers somewhat
flattish of separate scales, receptacles cylindrical. Scales of the
fertile involucre closed in fruit two beaked, containing two
achenes (seeds). The bur is densely prickly and hispid, the
achenes are oblong without pappus. At the upper end of the
involucre are two large prickles.

Each bur, as stated above, contains two flowers which develop
into the "seeds." The statement is frequently made "that one
of these may germinate the first year, and the other lie dormant
until a later time. It has been found that if a bur lies in such
a position that one seed is up and other down, the one next the
soil may germinate while the other remains dormant. This is
one reason why the plant is difficult to exterminate.

GIANT RAGWEED. KiNGHEAD — (Ambrosia trifida L.)

This weed is a stout scabrous, hispid or nearly glabrous an-
nual, three to twelve feet high. Leaves all opposite and petioled
three nerved, deeply three to five lobed, the lobes are ovate and
lanceolate and serrate, the upper leaf sometimes ovate and undiv-
ided; flowers monoecious, staminate borne in spikes surrounded
by the larger bract-like leaves. The involucre is turbinate to
obovoid, five to seven ribbed, beaked, each rib bearing a tubercle
near the summit; the involucre enclosing a single oily seed,

50.

SMALL RAGWEED — (Ambrosia artemisiaefolia L.)
This weed is a puberulent or hirsute annual, branched, one to
three feet high; leaves thin, once to twice pinnatifid; the upper
leaves are alternate, the lower, usually opposite, pale or canescent
beneath. Flowers monoecious, the staminate above and the pis-
tillate in the lower axils of the leaves. The fertile heads are
obovoid or globose. Short beaked. Four to six spined.

BURDOCK — (Arctium Lappa L.)

A coarse, branched biennial from a foot to three feet high;
hairy ; leaves large, roundish or heart-shaped, thin, obtuse, entire
or dentate, floccose tomentose beneath. Petioles deeply fur-
rowed, heads of purplish or whitish flowers, clustered or some-
what corymbose. The involucre surrounding the flowers (heads)
are lengthened into hooked tips, glabrous or slightly cottony.

Where burdocks are allowed to grow freely the fruit clings
to the fleece of animals, often forming large balls which may be
found on the tails of cattle and horses. When they are common
where sheep pasture the burdocks work into the wool which
soon becomes of little value. The plant is enormously produc-
tive.

51.

Suggestions for the Teacher

The most important point in connection with the study of
plants is to train the powers of observation. The child should
learn to discriminate between plants. While important to know
the name of a plant, it is far better to be able to tell what the
differences are. For instance, we have about 1100 different kinds
of flowering plants in the state of Iowa. They differ from each
other by one or more characters. The student should learn the
most important differences. To illustrate, we have in Iowa, two
kinds of morning glory, one the common bindweed or wild
morning glory, native to Iowa, with flowers from one to two
inches long, leaves large halberd, or arrow shaped, and running
rootstocks often called "roots" but these so-called roots have
small scales. The European bindweed has much smaller flowers,
less than one inch long, leaves small ovate and arrow shaped,
and running roots, no scales on these.

Many people do not know that we have two kinds of dandelion
in the state. The common one (Taxaxacum officinale,) olive green
seeds and coarsely divided leaves, and the red-seeded one (Tar-
axacum erythrospermum) with red or dark brown seed and
deeply divided leaves.

There are eight thistles in the state, all of these are easily
distinguished by a very simple key which I will insert here for
convenience. The characters are all very obvious.

A. Perennial. Plants living year after year.

1. Heads large, numerous.

a. Leaves woolly both sides — Woolly Thistle (C. can-

escens, N. W. la.)
a. Leaves hairy on lower surface — Field Thistle (C.

discolor, la. general.

2. Heads small. Leaves slightly woolly underneath —

Canada Thistle (C. arvense, la. general.)

3. Heads large, usually 1, blooms early — Prairie Thistle —

(C. Hillii, la. general.)

B. Biennial. Plants form flowers the second season and then
die.

1. Heads with numerous sharp spines. Leaves very spiny

— Bull Thistle (C. lanceolatum, la. general.)
2. Head not spiny but sticky.

a. Leaves not hairy or sparingly ; in swamps — Marsh

Thistle (C. muticum, N. la. rare.)
a. Leaves hairy at least below.

Heads very large ; in swamps — Iowa Thistle — ( C.

iowense, meadows, la. general.)
Heads smaller; in woods — Wood Thistle (C. altis-

simum, E. la.)

The C. of the Sunflower family (Compositae), stands for the
genus Cirsium, which includes all of the true thistles. There are
other so-called thistles but the botanical name should only be
applied to the plants of this genus. The Russian thistle is not
a true thistle but belongs to the Goosefoot Family (Chenopo-
diaceae. ) The student should early recognize that certain plants
belong to some particular family and with a little practice such
plants as the sunflower, aster, goldenrod, purple cone flower,
may weed, and dandelion, will readily be recognized as belonging
to the composite family.

To facilitate the work of the teacher I have added a few ques-
tions which the student should answer. If the teacher is not
familiar with the terms that are here used, any of the larger
dictionaries will assist in getting the definitions, sepals, petals,
stamens, pistils, bracts, ray flowers, achene, etc. Simple leaves
may be linear, hastate, halberd, cordate, acute, acuminate, cleft,
lobed, dissected, and sagittate. Compound leaves may be pin-
nate (rose), and palmately (horse chestnut) compound. Fruits
may be berry (black nightshade, horse nettle), capsule (Jimson
weed), pod (clover and sweet clover), achene (sunflower, thistle),
caryopsis or grain fruit (corn, wheat, crab grass). Flowers,
regular (morning glory, strawberry), irregular (sweet clover,
sweet pea), polypetalous (crowfoot, clover), gameopetalous
(morning glory, horse nettle), apetalous (smartweed), calyx col-
ored like petals (smartweed.)

QUESTIONS AND TOPICS.

1. Describe accurately in your own language the chief points
of the following weeds: Greater or giant ragweed, dandelion,
quack grass, burdock, velvet weed, dock, parsnip, cocklebur and
other weeds mentioned in the Iowa weed law.

2. Note the methods of reproduction in the following weeds :
Canada thistle, dock, quack grass, foxtail, burdock, bull thistle,
cocklebur, horse nettle, velvet weed.

3. Note the difference in the underground parts of the fol-
lowing weeds: Morning glory, quack grass, milkweed, sheep

53.

sorrel. Determine whether roots or underground stems. Are
there any small scales present on the underground portions ?

4. How do you know that quack grass is a stem? How do
you know that milkweed is a root?

5. Determine the duration of life of as many weeds as pos-
sible. For example, foxtail (annual), wild barley or squirrel
tail grass (winter annual), bull thistle, wild carrot and burdock
(biennial), quack grass, Canada thistle, tanweed, morning glory
(perennial.)

6. Determine the root and stem character of as many weeds
as possible. Determine also the space they occupy in the soil,
whether deep or shallow rooted and how these roots injure the
crops.

7. Determine the number of seeds produced by some indi-
vidual weeds and make a record of the result.

8. Now determine the weed seeds produced per acre of some
weed.

9. Make a study of the following weed seeds : Foxtail, cockle-
bur, burdock, plantain, catnip, ragweed, dock, smartweed, butter
print or velvet leaf, may weed or dog fennel, mustard, sweet
clover, dodder, lambs quarter, buckhorn, wild carrot and pig-
weed.

10. Why are weeds detrimental to agriculture?

11. Determine the number of different kinds of weeds on a
given area. If you cannot name them dry the specimens and
send to me for identification.

12. In what ways do weeds spread? Give a concise account
of the methods and give illustrations of each.

13. What weeds are scattered by the wind, water, snow, ani-
mals and explosive properties.

14. Germinate some of the weed seeds. Determine the per-
centage of germination and study the characters of the weed
seedlings. How many seeds in the cocklebur and how many seeds
germinate the first season.

15. Try to germinate the seeds of some weeds immediately;
take another lot of the same kind, stratify in sand or earth and
allow them to freeze. Plant the seed in April. If you find any
difference determine the percentage in each case.

16. Determine the percentage of impurities in clover seed.
Obtain bulletin 115 of the Iowa Agricultural Experiment Sta-
tion which gives methods in detail. This bulletin will be sent
upon application.

17. Make a collection of weeds and weed seeds. Specimens
can be preserved and dried for reference.

54.

18. Determine the kinds of weeds found in the following
places : The corn fields, garden, roadsides, pasture and in vacant
lots, door yards and barn yards.

19. After these points have been carefully studied and the
habits of the plants determined, suggest a method of extermina-
tion of weeds studied.

20. Determine the yield of corn or other crops per acre in
some clean fields and compare them with some weedy fields.
Which fields give the largest yield.

21. Become familiar with a few poisonous plants such as
poison ivy, which is frequently a climbing plant, jimson weed,
a rank smelling herb with large white flowers, the cowbane with
clustered roots and clustered white flowers in umbels like parsnip.

BIBLIOGRAPHY.

The following papers and books may be used for reference:

Pammel, L. H. Some weeds of Iowa. Bull. la. State College
Experiment Station, Ames, 70. Russian thistle, Bull. 26; Quack
and Wheat grasses, Bull. 83; Press bulletins, 11, 12 and 13.
These may be had, except No. 70, by writing Prof. Curtiss, Ames.

Pammel, L. H. and Charlotte M. King. Notes on Eradication
of Weeds with experiments made in 1907 and 1908. Bull. 105.
Iowa Agricultural Experiment Station.

Results of Seed Investigations for 1908 and 1909. Bull. 115.
See also Bull. 88 of the same station by L. H. Pammel, R. E.
Buchanan and Charlotte M. King. Iowa Agricultural Experi-
ment Station.

Pammel, L. H. Weeds of the Farm and Garden. Orange Judd
Co., New York. About 300 pages. In press.

Floras and Manuals. The following cover our territory.

Britton. Manual of the Flora of the Northern States and
Canada. Henry Holt & Co.

Robinson and Fernald. Gray's Manual of Botany of Northern
United States. American Book Co.

Clark, Geo. H. & Fletcher, J. Farm Weeds of Canada. Pub-
lished by the Department of Agriculture, Canada. Price $1.00.

Htichcock, A. S. & Geo. L. Clothier. Report on Kansas Weeds.
Bulls. Kansas Agricultural Experiment Station, 57; 80.

Key for Families

1. Plants grass-like.

Stems solid, 3 angled, Cyperaceae 34

Stems hollow, round in cross section, Gramineae 30

2. Plants not grass-like.

Flowers inconspicuous.

Flowers with thin, not greenish bracts, Amaranthaceae 37
Flowers greenish, succulent herbs, Chenopodiaccae 37
Flowers greenish, 3 sepals enclosing the seed, acrid herbs,

Polygonaceae 34
Flowers conspicuous.

Succulent plants, Portulaceae 40

Plants not succulent, acrid, sepals petal-like,

Polygonaceae 34
Plants not succulent, acrid, sepals and petals present,

Ranunculaceae 40
Plants not acrid.

Stems with swollen joints, . . Caryophyllaceae 37

Stems with joints not swollen.

Flowers regular of separate parts.

Flowers in umbels, Umbelliferae 42

Flowers not in umbels.

Pungent herbs, 6 separate stamens,

Cruciferae 40
Bland herbs, stamens in one set,

Malvaceae 41

Flowers in one pie ce, Gamopetalous
Flowers irregular, stem 4 angled, Labiatae 47
Flowers regular, stem not 4 angled.

Twining plants, Convolvulaceae 45

Not twining plants.

Conspicuous flowers not in heads.

Fruit a berry, Solanaceae 48

Flowers in heads, Compositae 49

Flowers inconspicuous.

Plantgainaceae 49

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