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U. S. DEPARTMENT OF AGRICULTURE.
BUREAU OF PLANT INDUSTRY—BULLETIN NO. 84.

B. T. GALLOWAY, Chief of Bureau.

THE SEEDS OF THE BLUEGRASSES,

I. THE GERMINATION, GROWING, HANDLING, AND ADULTERATION
OF BLUEGRASS SEEDS.

By Epa@ar Brown, Botanist in Charge of Seed Laboratory.

II. DESCRIPTIONS OF THE SEEDS OF THE COMMERCIAL BLUEGRASSES
AND THEIR IMPURITIES.
By F. H. Hitiman, Assistant Botanist, Seed Laboratory.

IssuED NovEMBER 14, 1905.

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WASHINGTON:
GOVERNMENT PRINTING OFFICE.
POS:

BUREAU OF PLANT INDUSTRY. >

B. T. GALLOWAY,
Pathologist and Physiologist, and Chief of Bureau.

VEGETABLE PATHOLOGICAL AND PHYSIOLOGICAL INVESTIGATIONS.

ALBERT F. Woops, Pathologist and Physiologist in Charge, Acting Chief of
Bureau in Absence of Chief.

BOTANICAL INVESTIGATIONS.
FREDERICK V. CoviLuE, Botanist in Charge.

FARM MANAGEMENT.
W. J. SprnuMan, Agriculturist in Charge.

POMOLOGICAL INVESTIGATIONS.
G. B. Brackerr, Pomologist in Charge.

SEED AND PLANT INTRODUCTION AND DISTRIBUTION.
A. J. Prerers, Botanist in Charge.

ARLINGTON EXPERIMENTAL FARM.
L. C. Corsert, Horticulturist in Charge.

{INVESTIGATIONS IN THE AGRICULTURAL ECONOMY OF TROPICAL AND
SUBTROPICAL PLANTS.

O. F. Cook, Bionomist in Charge.

DRUG AND POISONOUS PLANT INVESTIGATIONS, AND TEA CULTURE
INVESTIGATIONS.

Ropney H. True, Phystologist in Charge.
DRY LAND AGRICULTURE AND WESTERN AGRICULTURAL EXTENSION.
Caru 8. ScorIELp, Agriculturist in Charge.
EXPERIMENTAL GARDENS AND GROUNDS.
E. M. Byrnes, Superintendent.

SEED LABORATORY.
Epa@ar- Brown, botanist in Charge.

J. E. RockweE.u, Editor.
JAMES EK. JonEs, Chief Clerk.

SEED LABORATORY.
SCIENTIFIC STAFF.
EpeGar Brown, Botanist in Charge.
F. H. HriuMan, Assistant Botanist. J. W. T. Duvet, Assistant.
2

LEDER OF TRA NSi ITA:

U.S. DEPARTMENT OF AGRICULTURE,
BUREAU OF PLanT INDUSTRY,
OFFICE OF THE CHIEF,
Washington, D. C., July 15, 1905.

Sir: I have the honor to transmit herewith and to recommend for
publication as Bulletin No. 84 of the series of this Bureau the accom-
panying technical paper entitled ‘*‘ The Seeds of the Bluegrasses.”

This paper was prepared by Mr. Edgar Brown, Botanist in Charge
of the Seed Laboratory, and Mr. F. H. Hillman, Assistant Botanist,
Seed Laboratory, and has been submitted with a view to publication.

The bluegrasses are among the most important forage plants in
many sections of the United States and Europe, and large quantities
of seed are harvested annually for use in this country and for expor-
tation.

The process of cleaning the seed of the bluegrasses for market is
such that many of the distinguishing characters are lost, and separate
descriptions are necessary for the hand-picked and commercial seed of
the same species.

The seeds of the different commercial species are so nearly alike in
general appearance that at present none but the trained observer can
distinguish between them. ‘This similarity of appearance has encour-
aged the use of the cheaper and less desirable species, especially
Canada bluegrass, for the adulteration of or substitution for the more
expensive species.

The descriptions and illustrations herewith given of the bluegrasses
and of their impurities will be of great value in furnishing seedsmen
the necessary information to enable them to distinguish the different
species.

The accompanying illustrations are necessary for a complete under-
standing of the text.

Respectfully, B. T. GaLLoway,
Chief of Bureau.
Hon. JAMES WILSON,
Secretary of Agriculture.

CONE Bas:

Page.
I. THE GERMINATION, GROWING, HANDLING, AND ADULTERATION OF BLUE-

GRASS SEEDS se bye dears LO Willys seer tne eee SR ee eae. RO tas 9
Description of commercial and hand-gathered seeds. -......--------- g
Grades'and quality of commercialiseeds2-2.:-22--22--.-.2--.225---- 10
PAGING ER ACLOM ee) ee ne eae Peet ere eee Re ae Ase kk 10
Wei odnG sere busin el sate ee ree ieee eee eee em eS eee ee oar ae 11
Germination ....... Boa Ste sey es age ee EE aertiy te ae 12
Growinerands han Glin Gia a ee ee cee ee en ee eo ae 12

ROO Mpratcnsisa WentuckysOlUeerassy pers = hea ae cee ee ae ee ae 12
oa.compnessa. (Canada blweorass)= sess 5ne= 2 2 Sees ee 13
Poa trivialis (rough-stalked meadow grass) _.---.--------------- 13
LOGNEMOLAUS (WOOCnIMeAd OW: CLASS) iene see oe eee eS 13
Poon oras (Owl mead OwacTass)) peace ye ee eee 13
iRoaxorachniujerds(hexas*blueonass) =< 25. a. ss 28 So sh ee 14
Poa annua (annual bluegrass) -.-.-.--- diet Ma ep Se eee See aes 14
OCOLpU AA alpine mMCAdOW.OTASS)) ease See Se sn eee 14
J POXER SUMO NA NCO oy Signe 5 Ges NN aif ats oy oe Con epee ee ea feng EO 14
II. DESCRIPTIONS OF THE SEEDS OF THE CoMMERCIAL BLUEGRASSES AND THEIR
ITB URUELES Ss oye le gre MMM ADS fer ee Sel nee Oe ei eee 15
NER We OraSseS ees ee gs ee ee Soci ee es 15
Key to the seeds of the more common species of Poa as found
OneherbariwmMespeCimmen sms see epee ee ees atte ee ee 18
Key to commercial bluegrass seeds after preparation for market. - 19
Comparison of the principal distinguishing characters of blue-
OAT ISIS) TS (SLEIG Shes is eh els teehee ee ee nia ciate 20
DESETIPEOMSKOMSPCClES A eet oer ee My ele ee en ge os 22
Poa pratensis L., Kentucky bluegrass, June grass........_-- 22
Poa compressa L., Canada bluegrass, flat-stemmed bluegrass. - 24
Poa trialis L., rough-stalked meadow grass...............- 24
‘Poa nemoralis ., wood meadow erass.2 -22.2.. i522 2....-2. 26
Poa triflora Ehrh. (P. flava L., P. serotina Ehrh.), fowl
MMCACO Ws CTASS natal Se mre Ul tO ser ae ee ee ueecye Ge er as 27
Lomarachnuyerd Lor. bexas) bluegrass... 2 225.2222 see 28
ogrannua lus. -annualsmeadow-erass 2 =. - 4226.25 2 Ls 29
OORMDING lhe. alpine mead@weerass: = 54. S465 eee eS 29
BOOBS CLUCOREL OCT kOe tae rae ee ee ree een 30
1 EURO UMP OCIASNO) Oe ee as se ne A eS Si) Ae ae oO ol
Panicularia nervata (Wilid.) Kuntze, nerved manna grass,
sometimes called fowl meadow grass_...........----- 31
Panicularia americana (Torr.) MacM., reed meadow grass,
water meadow grass, tall manna grass ..__._......._.. 31

6 CONTENTS.

‘IJ. DESCRIPTIONS OF THE SEEDS OF THE COMMERCIAL BLUEGRASSES AND THEIR
Impvuritres—Continued.

Weed seeds commonly found with commercial bluegrass seeds
Bursa bursa-pastoris (L.) Britton, shepherd’s-purse --........---
Lepidium virginicum L., peppergrass ..-----.-------- <
Cerastium vulgatum L., mouse-ear chickweed
Alsine media L., common chickweed
Alsine’ graminea: (ie) “Britton soe ee ee ee
Carduus arvensis (is) Robs-. Canada thistle 9a— e
Taraxacum taraxacum (L.) Karst., dandelion
Matricaria inodora L., scentless camomile
Hieraciwim sp;, hawk weeds = 2 oes ne ee eee
Anthems cotula ts., dog fennel, may weed = 22 a ee
Chenopodium album L., lamb’s-quarters, pigweed_..-..--.-------
Plantago lanceolata L., rib-grass, buckhorn, English plantain...
‘Rumez crispus a. curled:dockoo-= 2 Soe ee
Rumex acetosella L., sheep’s sorrel, sorrel
Veronica arvensis L., corn speedwell
Juncustenuis Willd slender rush®. 33-2 e ee eee
Juncoides campestre (L.) Kuntze, field rush
SUNGCOLAES CLOTAGE DCS SWOOG TUS Ie Ba ee
Carex cephalophora Muhl., oval-headed sedge. .---..------------

Ergot occasionally found in commercial bluegrass seed
Claviceps purpurea (Fr.) Tul., ergot

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TEXT FIGURES.

Avspikeletiol:Poas 5 <cawetee ee e e

ATT OLEHISIS) 8 (hissed ager Ae Ore En eae Aen: Or) S

. Unrubbed Kentucky bluegrass seed (Poa pratensis) .........-..----.
. Seeds of Kentucky bluegrass (Poa pratensis) - -- -
. Different forms of commercial seeds of Kentucky bluegrass (Poa

. Commercial seeds of Canada bluegrass (Poa compressa)-....-.------

Seeds of rough-stalked meadow grass ( Poa trivialis)........-...-----

. Seeds of wood meadow grass ( Poa nemoralis) - - - -
. Seeds of fowl meadow grass (Poa triflora)..---- -
. Seeds of Texas bluegrass (Poa arachnifera) -.----
. A cluster of Texas bluegrass seeds matted by the webby fibers. ..--..
. Seeds of annual meadow grass (Poa annua)... -.-
. Seeds of alpine meadow grass (Poa alpina) ----- -
HI OCCUS Ole OCISUG CINCO sx oe eee ee a a
. Seeds of nerved manna grass ( Panicularia nervata) ..-..2..---------
. Seeds of water meadow grass ( Panicularia americana) .......--------
. Seeds of shepherd’s-purse ( Bursa bursa-pastoris) -
. Seeds of peppergrass (Lepidiwm virginicum) ....-
. Seeds of mouse-ear chickweed ( Cerastium vulgatum).....-.----------
. Seeds of chickweeds (Alsine media and A. graminea)...--..-.-------
. Seeds of Canada thistle ( Carduus arvensis) ----- - -
. Prickles often found with bluegrass seed ----.---
. Seeds of dandelion (Taraxacum taraxacum)...--.
. Seeds of scentless camomile ( Matricaria inodora) -
. Seeds of hawkweed (Mieracitumsp.)--.--.-------
. Seeds of dog fennel (Anthemis cotula) .......----
. Seeds of lamb’s-quarters (Chenopodium album) .- - -
. Seeds of rib-grass ( Plantago lanceolata) ...-..-----
. Seeds of curled dock ( Rumex crispus) -.-.-------
. Seeds of sorrel (Rumezx acetosella)....-..--------

Seeds of corn speedwell ( Veronica arvensis) -.--- -

. Seeds of slender rush (Juncus tenwis)....-.------
. Seeds of field rush (Juncoides campestre).--------
. Seeds of wood rush (Juncoides albida).-..-------
. Seeds of sedge ( Carex cephalophora) -...---.------
. Ergot ( Claviceps purpurea) of Kentucky bluegrass

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ine Se eS OR Vile BEUEGK ASSES.

J. THE GERMINATION, GROWING, HANDLING, AND
AOUEGER ATION OF BEUBEWASS SEEDS:

By EpeGar Brown,

Botanist in Charge of Seed Laboratory.

DESCRIPTION OF COMMERCIAL AND HAND-GATHERED SEEDS.

Great difficulty is experienced in distinguishing the seeds of the.
species of Poa. It is especially important to be able to recognize
them, as the species vary greatly in value and the seed of one species
is frequently substituted for that of another.

The descriptions of the seeds of Poa already published have been
largely those of complete or hand-gathered specimens. But the seeds
of some kinds as they appear on the market are more or less broken
and have lost many of their distinguishing characters. The process
of cleaning often rubs off the web at the base of the seed and the
hairs along the sides and breaks the tip. On this account descriptions
based on specimens of perfect seeds are not to be relied upon in
identifying certain commercial Poas.

The mutilation of seeds during the process of cloning | is especially
marked in home-grown seed of Kentucky bluegrass (Poa pratensis).
Even the fande gathered seed of rough-stalked meadow grass (Poa
triwalis) is frequently so much injured about the slender apex as to
increase greatly the difficulty of distinguishing it from that of Ken-
tucky bluegrass. On the other hand, the commercial seeds of wood
meadow grass (Poa nemoralis) and foul meadow grass (Poa triflora)
retain much of the pubescence on the glume, often the web, and are
usually not broken on the tip.

It is important that descriptions and illustrations to be used in prac-
tical seed testing be taken from the commercial as well as hand-
gathered seed and be comparative in character. Those given in this
paper have been prepared from both hand-gathered and commercial
seed. The term seed is here used in its popular sense.

9

10 THE SEEDS OF THE BLUEGRASSES.

GRADES AND QUALITY OF COMMERCIAL SEEDS.

The seeds of all species except Kentucky bluegrass are known to the
American trade in only one grade. This is the so-catled ‘‘faney”
grade, which is based on relative cleanness and on the bright appear-
ance of the seed. ‘The quality of different samples passing under this
grade name is not necessarily uniform, but among the more careful
dealers a purity standard of from 80 to 90 per cent is usually maintained.

The seeds of Kentucky bluegrass and of Canada bluegrass raised in
this country are usually much cleaner and freer from foreign seeds’
than the EKuropean-grown seeds of rough-stalked meadow grass, wood
meadow grass, and fowl meadow grass.

Kentucky bluegrass seed is-~commonly offered in two grades—
‘‘fancy,” and ‘*extra-clean” or ‘‘extra-cleaned.” The latter names are
a survival of the time when the seed was hand cleaned and the ‘‘ extra-
clean” was the best seed on the market. With the advent of improved
machinery the ‘*‘ fancy” grade was established and it is now the only
gerade generally accepted by the intelligent purchaser. The ‘‘extra-
clean” still on the market belies its name, since it consists of the chaff
or cleanings from the fancy seed, and consequently contains only light
seed. Samples of ‘‘extra-cleaned” as offered usually contain less than
10 per cent of seed.

In some cases the growers find a sale for the rough or uncleaned
seed after it has been passed through a feed cutter. In this condition
it has very much the appearance of fine-cut straw with a large per-
centage of chaff, and can be scattered over pastures and other areas,
seeding them as effectually as could be done by the use of fancy
recleaned seed. If well cured, the germinating quality of such seed
is excellent, and the mass contains from 60 to 70 per cent of pure seed.
Except for foreign trade the percentage of germination has little to do
with the price and grade of bluegrass seed.

Aside from adulterated samples the purity of ‘‘ fancy” seed of all
species of bluegrass is usually good. Of the 2,887 samples of Ken-
tucky bluegrass tested by the Zurich Seed Control Station from 1876
to 1903 the average purity was 86.3 percent. Of the 69 samples
tested in the Seed Laboratory of the Department of Agriculture
during the past year the average purity was 75.02 per cent.

ADULTERATION.

The seed of Canada bluegrass (Poa compressa) is the only kind
used as an adulterant of Kentucky bluegrass in this country. During
the year 1904 649,451 pounds of Canada bluegrass seed were imported
from Canada, practically none of which is being sold under its true
name. Among the samples of seed sold for Kentucky bluegrass and
sent to the Seed Laboratory for examination a large number have

WEIGHT PER BUSHEL. EL

contained from 30 to 50 per cent of Canada bluegrass seed and several
have been entirely composed of the Canada seed.

It is significant in this connection that the price of Canada bluegrass
seed varies with that of Kentucky bluegrass seed, being usually about
one-half that of the latter. This adulteration is not merely a simple
fraud by which the farmer pays for what he does not get, but the
difference in the resulting pasture or hay crop is very important.
Canada bluegrass, while having many good qualities in common with
other species of Poa, is by no means a pasture grass, for which purpose
Kentucky bluegrass is unexcelled.

The seed of wood meadow grass (Poa nemoralis) is sometimes adul-
terated with other species of Poa, and samples have been offered under
this name that contain no wood meadow grass seed. One sample tested
in the Seed Laboratory contained 59.4 per cent of Poa pratensis and
23 per cent of Poa compressa, the remainder being chaff and dirt.
Samples of fowl meadow grass (Poa triflora) have been examined
which consisted largely of various common grass and clover seeds
combined with an abundance of weed seeds. These samples contained
small quantities of Kentucky and Canada bluegrass seeds, much chaff
and dirt, and some of them no seeds of fowl meadow grass.

The seed of Kentucky bluegrass is used to adulterate that of the
higher priced Poa trivialis, pure seed of the latter species usually
being hard to obtain. Some of the German authorities say that it is
necessary for every farmer to save his own seed of this grass in order
to be sure that it is pure. Hunter“ says:

Previously to 1883 good and genuine seed of this species (Poa trivialis) could not
be obtained in this country [England]. Seed of the Poa pratensis was commonly
supplied for it. It is now less difficult to procure genuine seed, but large quantities
of seed of Poa pratensis (which usually costs about one-third the price) are prepared

to resemble and are sold for Poa trivialis, and it is only by careful microscopic exam-
ination that the nature of the seed can be determined

WEIGHT PER BUSHEL.

The standard weight of a bushel of bluegrass seed of any grade is 14
pounds. The actual weight, however, varies from 6 to 8 pounds in the
case of *‘extra cleaned” to 27 pounds or more for especially good sam-
ples of fancy recleaned seed. In the bluegrass region of Kentucky it is
the usual practice to sell the seed fresh from the strippers or cured in
the chaff by the bushel of 14 pounds, but it is always weighed, not
measured. The cleaned seed is always sold by the pound. As the
weight per bushel of bluegrass seed depends directly on its purity,
it is customary in quoting the price of ‘‘fancy” seed to accompany it
with a statement as to the weight per bushel.

$$ —

«Treatise on Permanent Pasture Grasses, James Hunter. Chester, England, 1901.

12 THE SEEDS OF THE BLUEGRASSES.

The foreign trade is much more critical than the domestic trade, and
the seed exported usually weighs from 22 to 24 pounds per bushel,
while the domestic trade is content with seed weighing from 18 to 20
pounds. The heavier seed costs more per pound than the lighter seed,
since there is more labor in its preparation, but it is cheaper for the
purchaser.

GERMINATION.

The germination of commercial bluegrass seed is often poor. At
the Zurich Seed Control Station the average percentage from 3,069
samples of Kentucky bluegrass seed tested from 1876 to 1904 was 65
per cent, while 908 samples of Poa trivialis tested showed an average
of 72 per cent. The quality of Kentucky bluegrass seed as respects
germination appears, however, to be improving. Last year’s tests at
the Zurich station gave an average of 68 per cent, while a few years
ago 50 per cent was considered fair or satisfactory. Only the best
seed goes to Europe, and consequently the percentage of germination
of that offered in this country is low. As carefully cured seed will
germinate from 80 to 90 per cent, the cause for the poor quality of
commercial seed is doubtless to be found in the way it is harvested and
cured.“ The usual process is to pile the freshly stripped seed in ricks,
either outdoors or in barns. This mass heats quickly if not stirred
often during the first few days. One pile left without stirring reached
a temperature of 140° F. in sixteen hours, killing all the seed.

GROWING AND HANDLING.

With the exception of our native western species, more or less seed
of all the commercial Poas is gathered in Europe, where they are
found wild. The harvesting is done by hand from the natural mead-
ows, woods, or other uncultivated areas. The seed is cleaned by hand
and carried to market in small quantities and collected by dealers who
supply the trade. The United States furnishes Europe with Kentucky
bluegrass seed, and Europe furnishes the seed of rough-stalked meadow
grass and wood meadow grass, as well as of the other commercial
species of Poa used in this country.

Poa pratensis (Kentucky bluegrass).—The bulk of the Kentucky
bluegrass seed comes from a limited area known as the bluegrass
region of Kentucky. The counties of Bourbon, Scott, Fayette, Clark,
and Woodford furnish most of it, although there is a small quantity
saved in Shelby County. Some is harvested in southwestern Illinois,
and there is another area on the border between Missouri and Iowa
where a considerable amount of seed is saved. The seed is gathered
from the natural woodland pastures as well as from those where it has

io

aSee Bulletin No. 19, Bureau of Plant Industry, ‘‘ Kentucky Bluegrass Seed: Har-
vesting, Curing, and Cleaning.”’

GROWING AND HANDLING. 18

been sown. It is customary to graze cattle on it nearly the entire
year, as they do not materially injure the crop of seed if they are kept
out for two or three weeks immediately before gathering. The seed
is harvested by pulling the heads off with a stripper, the grass not
being cut for hay. The cleaning is a rather difficult process, as it is
necessary to rub the heads thoroughly in ‘order to separate the seed
from the web at the base. The last of the chaff and dirt which is
blown out during the cleaning process is sold as ‘* extra-cleaned” seed.

Poa compressa (Canada bluegrass).—The seed of Canada bluegrass
is mostly produced in the Province of Ontario, along the north shore
of the eastern half of Lake Erie. The soil is a heavy clay on lime-
stone. In this section Canada bluegrass is not sown, but appears as a
volunteer in any fields that are not kept under cultivation, making a
thick growth and crowding out other grasses and weeds. It is nearly
always found in wheat fields when the wheat crop is a partial failure.
In this case the seed, ripening as it does at the same time as the
wheat, is thrashed with it and screened out in cleaning. Where the
seed is harvested alone the grass is cut with a mowing machine and
cured the same as ordinary hay, and afterwards thrashed with a
clover huller or grain separator. The hay is bright green, even when
not cut until after the seed is ripe, and is well liked by some farmers
as feed, while it is considered hard and of little value by others. A
good crop is from 200 to 300 pounds of clean seed per acre. There
has been some demand for this seed in the Southeastern States under
the name of Virginia bluegrass. The seed is easily cleaned, as it is
comparatively free from wool at the base and does not require rub-
bing, as does Kentucky bluegrass seed. No special machinery is used
except rather long sieves to insure sufticient screening.

Poa triwialis (rough-stalked meadow grass).—The wholesale trade
in the seed of rough-stalked meadow grass is largely confined to the
city of Hamburg, Germany. The seed is collected in the neighbor-
hood of that city and in the marshes of the Elbe. Seed of good
quality is also supplied from Denmark, where in one locality this
grass is grown especially for seed, and it is said to yield as much as
400 pounds to the acre. The seed is stripped or the grass is cut and
the seed allowed to after-ripen, when it is cleaned by hand.

Poa nemoralis (wood meadow grass).--The seed of wood meadow
grass 1s gathered by hand in the woods of Germany, and cleaned in
the same manner as is the seed of Poa trivialis.

Poa triflora (fowl meadow grass).—Though widely distributed
throughout the northern portion of the United States, this species is
chiefly a natural meadow grass of lowlands, and is usually so mixed —
with sedges and other grasses that seed collection on a commercial
scale has not thus far been undertaken in this country. The seed of
this species on the market comes from Europe and is very poor.

14 THE SEEDS OF THE BLUEGRASSES.

Prof. L. R. Jones, of the Vermont Agricultural Experiment Station,
reports the seed production from a nearly pure stand of this grass as
amounting to 6 bushels of 19 pounds each per acre. A small plat
yielded seed at the rate of over 7 bushels per acre. The seed is pro-
duced abundantly and ripens evenly. In Vermont it is harvested in
the latter part of July. The name fowl meadow grass is often applied
to another lowland grass, Panicularva nervata.

Poa arachnifera (Texas bluegrass).—The seed of Texas lice is
gathered by hand in northern Texas. It is cleaned by rubbing
between the hands, and, owing to the long, woolly hairs at the base of
the seed, it is never ‘‘ fancy clean.” The best seed is produced on
rich, black, waxy soil, and is ripe about May 1 to 15. Only a small
quantity is gathered each year, and consequently it is high priced and
can not be considered as a commercial seed at the present time.

Poa annua (annual bluegrass).—The seed of the annual bluegrass is
not on the market in this country, though the plant is common about
dwellings, especially in the South and East, and ripens its seed
throughout the summer. The seeds do not ripen evenly, the upper
ones falling before the lower flowers have opened. The seed is
gathered and used to some extent in Europe.

Poa alpina (alpine meadow grass).—Alpine meadow grass is best
known in Switzerland, where the seed ripens from the end of June to
the middle of July. The viviparous form can be propagated by scat-
tering the buds during the hot weather.

Poa sudetica.—The seed of Poa sudetica, which is a Kuropean grass,
is rare in the market, but is occasionally quoted by French and by
German firms. It is sometimes mixed to some extent with the seeds
of the meadow grasses, particularly water meadow grass (Panicularia
americana).

In addition to the foregoing, other species of Poa occur in the
western and northwestern United States, where they contribute to
the native forage of the stock ranges. The seeds of these species,
however, are not found in commerce.

DEVE Str VONS OF THESSEEDS OF Dik COMMER:
CHIlS DIEU RCRASSES AND hE TR INE URITTES.

By F. H. Hitman,

Assistant Botanist, Seed Laboratory.

THE BLUEGRASSES.

The ‘‘seeds” of the species of Poa, or the bluegrasses, are the
ripened florets or individual parts of the smaller clusters, or spikelets,
of the general floral system of the plant. The number of florets in
each spikelet varies from two to nine in the different kinds of Poa
commonly found in commerce. ‘There is some variation in the num-
ber of florets in the spikelets of each species. The florets separate
readily at maturity, and well-cleaned samples of seed contain few
whole or partial spikelets.

A complete, mature spikelet embraces, besides its several florets, a
pair of chaffy scales, termed empty glumes, between which the florets,
or at least the lower ones, rest. The empty glumes, while somewhat

Fig. 1.—I.—A spikelet of Poa: a, stem of spikelet; b, empty glumes; c¢, florets, or ‘‘seeds.’’ II.—Single
floret, back view: a, callus; b, keel; c, intermediate veins; d; marginal veins; e, hyaline portion of
glume. III.—Single floret, side view: a, callus; b, rachilla segment; c, keel; d, intermediate vein;
e, marginal vein; f, margin of glume. IV.—Single floret, front view: a, rachilla segment; b, mar-
ginal fold; c, palea; d, keelsof palea. V.—Terminal floret, front view: a, rachilla segment; b, aborted
floret; c, palea. VI.—Caryopsis, or grain: a, location of embryo; b, keeled face; c, grooved face.

dissimilar, are keeled, acute, and one or three veined. The keel of
each is usually hispid-ciliate above the middle. A portion of the stem
of the spikelet often remains attached to the base of the empty glumes
when these are found in commercial samples.

Each mature, well-developed floret or seed consists of a caryopsis,
commonly called grain, two inclosing scales which, together with
the empty glumes, constitute the chaff, and a slender appendage,
the rachilla segment. (Fig. 1.)

15

16 THE SEEDS OF THE BLUEGRASSES.

The caryopsis corresponds to an individual grain in wheat, rye, and
barley, and consists almost entirely of the seed proper, to which is
added only the thin wall of the seed vessel. This is intimately blended
with the seed coat, the two forming the covering of the true seed.
The caryopsis is spindle-shaped and often broadest between the middle
and the base. It is often bluntly keeled along one face and more or
less evidently grooved along the opposite face. In the: commercial
bluegrass seeds the grain is amber-colored or dull wine-colored and
semitranslucent. The surface is finely granular and dull. The kernel
of the seed forms that part of the grain within the seed and seed-
vessel walls. It consists of the embryo and endosperm, the latter
forming the greater part. The embryo is situated at the basal
extremity of the grain and is evident externally as a small ridge, often
within a slight depression, on the keeled face. The grain adheres
along its grooved face to the palea in some species in which free grains
are not common in well-cleaned commercial seed.

The two chaffy scales of the floret differ chiefly in size, form, rela-
tive position, venation, and texture. The larger one, called the flower-
ing glume or simply the glume, incloses the edges of the other, termed
palea. The grain rests between the glume and palea, its keeled face
lying against the glume. The rachilla segment is at the base of the
palea and opposite the glume. It is one of the articulating sections of
the rachilla, or axis of the spikelet.

The characters by which the different kinds of bluegrass seeds are
distinguished one from another are afforded by the glume, palea, and
rachilla segment, and involve size, form, color, veins of the glume,
form and texture of the apex of the glume, and the pubescence.

The glume is stifish and more or less pointed at the ends. Its base
is marked by the presence of a small, somewhat knob-like appendage,
the callus. The latter bears the scar of attachment of the floret and,
in certain species, a more or less pronounced tuft of webby hairs.
The back of the glume is more or less keeled along its longitudinal
center. Besides the fold forming the keel, the edges of the glume are
infolded along the marginal veins. ‘The marginal folds often are most
pronounced within and sometimes are confined to the lower half of the
glume, in which event the upper margins usually diverge and become
spreading or flaring at the apex. The keel is strongly arched length-
wise in some species and in others is nearly straight. Five veins
traverse the glume longitudinally; one occupies the keel, two are at
the marginal folds and are termed the marginal veins, while the other
two are situated midway between the keel and marginal veins and are
called intermediate or, by some authors, lateral veins. The interme-
diate veins exhibit considerable variation in distinctness in the differ-
ent species. The vein occupying the keel extends to the apex. The
apex and often the upper part of the lateral margins of the glume in

THE BLUEGRASSES. 17

most species are thin and translucent, or hyaline. The extent of the
hyaline portion of the apex has much to do with the form of the latter
and is variable in the different species.

The palea is commonly more delicate in texture than the glume,
being partially hyaline. It usually is shorter than the glume, but in
some species equals or exceeds it in length. The difference in length
usually is most evident in the lower florets of the spikelet. Two veins
traverse the palea lengthwise and nearly meet at its apex. The mar-
gins of the palea are more or less acutely infolded along these veins,
which are called the keels of the palea. The keels are mostly covered
by the glume in some species, while in others they are almost wholly
exposed. There is some variation in this respect, however, among
seeds of the same species. The apex of the palea is often notched.

The rachilla segment is nearly cylindrical and usually somewhat :
curved. It is slightly expanded at the apex, which is obliquely trun-
cate, its terminal surface constituting the scar of at-
tachment to the succeeding floret. Different florets in
the same spikeletin certain species exhibit a marked
variation in the length of the rachilla segment, which
is shortest in the lower florets and conspicuously
longer in the terminal one, where it usuatly bears an
aborted floret as a small, pointed appendage.

The surface of the florets of different species of Poa
is subject to considerable variation. Some florets are

smooth, or glabrous; others bear numerous minute,
stiffish hairs, rendering the surface rough, or scabrous; Gee oe
and some have a fine, appressed pubescence covering grass seed (Poa
a part of the surface. Most of the species have a }”cunewenes of
more or less silky pubescence on the keel and mar- marginal vein; ¢,
ginal veins below the middle or somewhat higher on = Pupescence &
the keel. The intermediate veins are more rarely
pubescent. The keels of the palea are usually fringed with minute
hairs, or are hispid-ciliate, but in some species they are silky pubes-
cent. The basal web is wholly wanting in some species and in others
varies from a few fibers to a copious tuft. It readily separates from
the floret in most species. The rachilla segment is usually smooth,
but in some species it is appressed pubescent. The presence of the
hairs on the marginal veins often necessitates that care be used in
examining the rachilla segment with respect to pubescence. (Fig. 2.)

The color of mature seeds varies from very light brown to dark
brown. Sterile seeds are usually lighter or straw colored. Immature
seeds are more or less tinged with green; some are purplish. In cer-
tain species the glume is tinged with golden yellow near the apex.
The aborted terminal floret and all the hairs are white. The rachilla
segmént is lighter colored than the glume or palea.

5813—

18 THE SEEDS OF THE BLUEGRASSES. ~

_ Poorly cleaned samples are apt to contain many sterile florets.

These are slender, sometimes shrunken, and usually lighter colored
than the grain-bearing florets, which are comparatively plump and
often dark colored, owing to the color of
the grain appearing through thé thin palea.
(Fig. 3.)

The recognition of the several species of Poa,
when the identity is questionable, requires the
use of a good lens and a knowledge of the
principal distinguishing characters. A sample >
under examination should be spread thinly on

ape r, ty u ae
Fic. 3.—Seeds of Kentucky
bluegrass (Poa pratensis): a. a Sheet of paper, or, better still, on a black sur-

in bearing: , sterile. --
pone essay ies face. With a good light and means for turn-

ing the seeds over while under the lens, they can easily be examined
with reference to size, color, distinctness of veins. character of pubes-
cence, the condition of the margins of the glume, ete. Exposing the
different sides of the florets to the light while under examination is
often absolutely essential in determining the nature of the veins and
pubescence.

KEY TO THE SEEDS OF THE MORE COMMON SPECIES OF POA AS FOUND

ON HERBARIUM SPECIMENS.
Basal web present.
Web very persistent and conspicuous ---—----.--2=.--=222------- P. arachnijera.
Web easily removed, small; keel of the glume pubescent.
Intermediate veins distinct.
Intermediate veins sharply defined as narrow ridges; glume margins narrow,
not easily seen from the side; marginal veins usually smooth- P. trivialis.
Intermediate veins usually not sharply defined; glume margins broader, easily
seen from the side in fertile florets; marginal veins pubescent. P. pratensis.
Intermediate veins indistinct. Se,
Rachilla segment smooth or nearly so; florets 2-25 mm. long.
Florets usually broader above than below the middle; apex usually faring;

rachilla segment smooth ..-...------.--- wpe Ie ee ee eae P. compressa.
Florets not evidently broader above than below the middle; apex usually
golden yellow; rachilla segment sometimes rough ---..------- P. triflora.
Rachilla segment usually pubescent.
Florets 23-3 mm. long, usually not yellow at the apex. ----- P. nemoralis.

Basal web not present.
Florets strongly pubescent.
Intermediate veins distinct; palea keels prominent, oiten arched forward.
. P. annua.
Intermediate veins indistinct; palea keels not arched-----_--------- P. alpina.
Florets not pubescent —. 222 5-2. 22252 See eee P. sudetiea.

KEY TO COMMERCIAL SEEDS. 19

KEY TO COMMERCIAL BLUEGRASS SEEDS AFTER PREPARATION FOR
MARKET.

Seeds 4-6 mm. long; web longer than glume, forming a woolly tuft and causing the
SCOOSHORCLULOE Vita OWUISCILES: U1) CILCASCMIUD IC = see et ee se er P. arachnifera.
Seeds 2-2? mm. long, usually rubbed free from hairs and disconnected in the sample,
often more or less torn at the apex; commonest commercial kinds.
Intermediate veins distinct; seeds contracted at the apex and not wider above than
below the middle; hyaline margin of apex seldom present in rubbed seed.
P. pratensis.
Intermediate veins very indistinct; seeds broader above than below the middle; hyaline
margin of apex usually evident and flaring ..-....--:--...--.---- P. compressa.
Seeds 2-3 mm. long, chiefly unrubbed; disconnected or clinging somewhat in the
sample; usually not torn at the apex; smooth or the pubescence on the veins
and the web more or less evident.
Intermediate veins indistinct.

Rachilla segment usually pubescent; long, sterile racbilla segments conspicuously
common; intermediate veins scarcely evident; keeland marginal veins pubescent;
apex of seed often flaring; seed 23-3 mm. long ..-..--.-...-..- P. nemoralis.

Rachilla segment smooth; intermediate veins but slightly evident; keel and marginal
veins pubescent; apex of seed sometimes flaring; seed 2-23 mm. long. P. triflora.

Intermediate veins very distinct.

Rachilla segment smooth and slender; keel pubescent, marginal veins usually
smooth; apex of seed acute and compressed; seeds often distinctly curved as
VCUC On| ROM UILCESULE geen ea ees ee rhea nee Sa a= oe Bec arase Gaia P. trivialis.

OF THE BLUEGRASSES.

SEEDS

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22 THE SEEDS OF THE BLUEGRASSES.

DESCRIPTIONS OF SPECIES.
Poa pratensis L.
KENTUCKY BLUEGRASS, JUNE GRASS.

Spikelets 3-5 flowered; florets 2-2? mm., rarely 3 mm., long, lanceolate or fusiform
as viewed from the back, lanceolate or ovate-lanceolate as viewed from the side,
mostly acute or the terminal floret sometimes acuminate at the apex, glabrous
between the veins, varying from light brown to dark brown, sometimes tinged with
purple, sterile florets lighter; glume usually sharply keeled quite to the apex and
often strongly arched, particularly at the base; its marginal folds comparatively
broad, extending from the base nearly or quite to the apex, becoming hyaline-edged
above the middle in the lower florets, usually not expanded or flaring at the apex,
the edges nearly meeting in sterile florets, separated and usually distended forward
in fertile lower florets, often scarcely covering the palea keels of fertile terminal
florets, the hyaline edge more or less torn away and the margins jagged at the apex
in rubbed commercial seed; intermediate veins distinct and glabrous; keel and mar-
ginal veins silky pubescent below the middle or somewhat higher on the keel; basal
web well developed; pubescence and web wanting, except occasional traces of the
former, in well-rubbed commercial seed; palea nearly or quite as long as the glume,
its keels finely hispid-ciliate and usually covered for the greater part of their length
by the margins of the glume; rachilla segment slender, glabrous, varying from about
one-sixth of the length of the glume in the lower florets to one-half its length in the
terminal one; aborted floret of the sterile rachilla segment minute; grain 1; mm.
long, somewhat keeled and grooved, often broadest below the middle, reddish brown
or darker about the embryo, and semitranslucent. ‘Fig. 4.)

Fig. 4.—Different forms of commercial seeds of Kentucky bluegrass (Poa pratensis): a and 6, back
views: c-j, side views: g-j, iront views; j, a terminal floret.

Commercial Kentucky bluegrass seed is mostly free from the silky
and webby hairs present in hand-gathered samples, owing to the rubbing
process to which it is subjected before being marketed. The severe
rubbing results in more or less injury to the thin margins of the
olume, particularly at the apex, which is usually found to be more or
less torn when examined with a lens. Seeds of a well-rubbed sample
do not tend to cling in small bunches as do those which are unrubbed
or hand-gathered. Well-developed seeds are rather robust and have
the glume margins well separated and evidently distended forward.
Sterile seeds, or such as have the grain wanting or poorly developed,
are generally lighter colored, slenderer, and more compressed, while
the glume margins more nearly meet and are but slightly or scarcely
distended. Such are much lighter in weight than well-developed
seeds and consequently are mostly blown out with other chaff in well-
cleaned seed.

DESCRIPTIONS OF SPECIES. ies

Kentucky bluegrass seed is most readily confounded with that of
Canada bluegrass (Poa compressa) and rough-stalked meadow grass
(Poa trivialis). Owing to the difference in cost, Poa compressa is
sometimes mixed with or substituted for Kentucky bluegrass, while
the latter is sometimes similarly employed with respect to Poa

trivialis.

The characteristic differences between Kentucky bluegrass seed and
that of Canada bluegrass, as exhibited by the bulk samples and by
individual seeds under the lens, may be compared as follows:

KENTUCKY BLUEGRASS (Poa pratensis).

The usual, well-cleaned bulk samples are
brown in color.

Individual, well-matured seeds exhibit
the same brown color of the bulk sam-

ple.

Nearly all the seeds taper from. the cen-
ter to both ends and are not broader at
the apex than at the base.

The apex of commercial seeds is usually
torn, obtusely pointed, keeled, and
scarcely hyaline.

The intermediate veins are almost in-
variably distinct.

CANADA BLUEGRASS (Poa compressa).

Average samples lighter colored than
those of Kentucky bluegrass.

The lighter color of individual seeds af-
fords the principal character for the
preliminary recognition of these seeds
in mixtures.

Most of the seeds are broader at the apex
than at the base, often distinctly broader
at the apex than at the middle.

Apex, of commercial seeds often torn,
mostly expanded or flaring, often but
slightly keeled.

The intermediate veins are very indis-
tinct or apparently wanting.

A number of the samples of Kentucky bluegrass seed examined con-
tained seed of the Canada bluegrass. As the latter seed found in com-
merce usually contains the prickles or even the seeds of Canada thistle
( Carduus arvensis), these are often found in samples of Kentucky blue-
grass seed containing the Canada bluegrass seed. Their presence indi-
cates the admixture, since the Canada thistle dees not grow in the
seed-producing localities of Kentucky, while it is abundant in Canada,
where the Canada bluegrass is produced. Samples of pure Kentucky
bluegrass seed are apt to contain the prickles of horse nettle (Solanum
carolinense), sometimes wrongly called bull thistle, a prickly plant
common in the bluegrass region of Kentucky. These prickles are
similar to those of the Canada thistle, but may be distinguished, as
shown hereafter in this paper in describing the impurities of the blue-
grass seeds. The fact that Canada bluegrass only begins to flower at
the time Kentucky bluegrass is ripe precludes the possibility of the
mixture of the two kinds of seed owing to the fact of growth together.
Such mixture can occur only after the seed is gathered, through acci-
dent or intent.

24 THE SEEDS OF THE BLUEGRASSES.
Poa compressa L.

CANADA BLUEGRASS, FLAT-STEMMED BLUEGRASS.

Spikelets 3-9 flowered; florets 2-23 mm. long, oblong-obovate or the terminal one
lanceolate as viewed from the back, somewhat narrowly oblong as viewed from the
side, obtuse or the terminal one acute, smooth between the veins, straw colored or
light brown; glume somewhat arched, especially at the base, and strongly keeled at
the back, the keel often less pronounced at the apex than at the base; margins
infolded from the base ior about three-fourths the length of the floret in the lower
florets and nearly to the apex in the upper ones, hyaline-edged above the middle,
often broadly so at the apex, which is more or less flaring in the lower florets, the
thin apex often torn and jagged in commercial seed; intermediate veins very indis-
tinct or not evident, glabrous; keel and marginal veins silky pubescent below the mid-
dle; basal web present, slight; palea nearly or quite equaling the glume, finely hispid-
ciliate on the keels, which are usually more orless exposed above the middle, sometimes
from the base; rachilla segment glabrous, varying from about one-fiith the length
of the glume in the
lower florets to one-
half its length in the
terminal one; aborted
floret of the sterile
rachilla segment min-
‘ ute; grain 1-13 mm.
long, keeled and
slightly grooved,
semitranslucent.
(Fig. 5.)

Fie. 5.—Commercial seeds of Canada bluegrass (Poa compressa): a and B,
back views: c-e, side views: j-i, front views of florets; 7,a terminal fioret.

The seed of Canada bluegrass is the cheapest of the bluegrass seeds,
and is therefore not adulterated with other Poas, although it is itself
used as an adulterant to a considerable extent.

Pure samples of Canada bluegrass seed almost always contain the
prickles and sometimes the seeds of Canada thistle (Carduus arvensis);
therefore, the occurrence of these prickles with other kinds indicates
the use of this speciesas an adulterant. Their occurrence with seed
of Poa trivialis without evidence of the presence of Canada bluegrass
seed is noted under the discussion of P. tr/valis.

Poa trivialis L.
ROUGH-STALKED MEADOW GRASS.

Spikelets 2 or 3 flowered; florets 2-23 mm., rarely 3 mm., long, narrowly lanceolate
or the fertile terminal one ovate-lanceolate as viewed from the back, usually lanceolate
and curved as viewed from the side, laterally compressed as compared with other spe-
cies, straw colored or light brown and sometimes purplish, sharply keeled, the keel
somewhat arched; margins of the glume scarcely or but slightly distended, narrowly
and rather sharply infolded nearly or quite to the apex, which is hyaline-edged, very
acute and rarely expanded; intermediate veins very distinct as narrow and sharply
defined ridges; keel slightly pubescent below the middle, orrarely smooth; marginal
veins smooth or sometimes pubescent, basal web present; palea nearly equal to the
glume, its keelssmooth or finely hispid-ciliate near the apex and mostly covered by
the margins of the glume exceptin the larger terminal florets; rachilla segment very
slender, glabrous, varying from one-fourth to one-half the length of the glume;
grain 1-1} mm. long, keeled and grooved, semitranslucent, reddish brown. (Fig. 6.)

pei bade licen il talks ii tees pen

Sreptld

DESCRIPTIONS OF SPECIES. 25

Rough-stalked meadow grass is chiefly hand gathered; consequently
the commercial seed is apt to bear more or less of the web as well as
the silky pubescence on the keel. In many samples, however, both
are rubbed away.

This seed resem-
bles that of Poa
pratensis and that
of Poa compressa
so closely that both
are employed as
adulterants,
former apparently
to considerable extent, since it has frequently been found to constitute
a considerable part of samples of so-called rough-stalked meadow

ee
*s
+i

th € Fic. 6.—Seeds of rough-stalked meadow grass (Poa trivialis): a and b,

back views; c-e, side views; f and g, front views; g, a terminal floret.

gYass.

consisted almost wholly of Poa compressa.
Europe contained prickles of Canada thistle, but no seeds of Canada

bluegrass were found.

One sample examined marked ‘* Poa trivialis” from Europe
Several samples from

The principal distinguishing characters of the three species may be

compared as follows:

ROUGH-STALKED MEADOW GRASS
(Poa trivialis).

Commercial seeds are usu-
ally pubescent on the
keel vein, usually smooth
on the marginal veins
and bear more or less of
the webby hairs, conse-
quently cling together in
masses.

As viewed from the side,
the seeds are somewhat
curved, much narrower
than the others, the
glume margins usually
only slightly evident.

Apex of the glume usually
uninjured, strongly
keeled, acute, slightly
hyaline-margined, often
curved.

Intermediate veins sharply
defined as narrow ridges.

Rachilla segment very slen-
der and less variable in
length than in P. pra-
tensis or P. compressa.

KENTUCKY BLUEGRASS
(Poa pratensis).

CANADA BLUEGRASS
(Poa compressa).

Commercial seeds rarely pubescent on the veins and
the webby hairs wanting; consequently mobile in bulk,
not clinging in masses; unrubbed seed pubescent on
the marginal and keel veins.

Seeds mostly straight as
viewed from the side,
glume margins citen
strongly distended.

Apex of the glume more or
less torn in commercial
seed; keeled, sharply
pointed, hyaline-edged
and not curved in un-
rubbed seed.

Intermediate veins dis-
tinct as rather coarse
ridges.

Seeds straight, the glume
margins somewhat eyi-
dent from the side.

Apex of the glume often
torn, otherwise some-
what keeled, obtuselty
pointed, broader than the
base, hyaline-edged.

Intermediate veins indis-
tinct or apparently want-
ing.

Rachilla segment coarser than in P. trivialis and often

very short.

26 | THE SEEDS OF THE BLUEGRASSES.

Poa nemoralis L.
WOOD MEADOW GRASS.

Spikelets 2 or 3 flowered; florets 23-3 mm. long, lanceolate or ovate-lanceolate,
mostly acute at the apex, light brown, sometimes yellowish tinged -near the apex;
glume rather broadly keeled and somewhat arched at the back; margins of the
glume narrowly infolded quite to the apex or hyaline-edged and often flaring above
the middle; intermediate veins very indistinct; keel and marginal veins silky
pubescent below the middle; basal web slight; surface between the veins glabrous;
palea nearly equal to the glume, evidently shorter in florets having a flaring apex,
its keels hispid-ciliate and usually covered by the margins of the glume; rachilla
segment varying from one-fourth to three-fourths of the length of the glume, the
sterile rachilla segment very uniformly much longer than the others, more or less
appressed pubescent, the pubescence somewhat variable and sometimes nearly want-
ing; aborted floret of the sterile rachilla segment often one-half as long as the seg-
ment; grain 13 mm. long, rather slender, semitranslucent. (Fig. 7.)

Fic. 7.—Seeds of wood meadow grass (Poa nemoralis): a-c, back views; d and e, side
views; j-j, front views; j, a terminal floret.

Commercial wood meadow grass seed is not rubbed in preparation
for market, and therefore possesses much of its rather persistent and
prominent silky pubescence, and the thin tips of the florets are mostly
uninjured. The pubescence of the rachilla segment is persistent and
present in most of the seeds of all pure samples of this species. It
affords the most marked characteristic by which the seeds of P. nemo-
ralis may be distinguished from those of other commercial species of
Poa. The conspicuously longer rachilla segments of the terminal
florets are noticeably abundant in samples of this species, since these
florets constitute from one-third to one-half of all the seed. The
abundance of the long rachilla segments is helpful in distinguishing
these seeds from those of other Poas.

Commercial seed of P. nemoralis is apt to be very much adulterated
with other species of Poa. Of a number of samples examined less
than half were true to name. One was nearly pure Canada bluegrass
seed, and the rest consisted in part of one or all of the following
species: P. pratensis, P. compressa, and P. trivialis.

The following comparison of characters should render it compara-
tively easy to distinguish the seeds of ?. nemoralis from those of the
other species.

DESCRIPTIONS OF SPECIES. oT

Woop MEADOW GRASS KENTUCKY BLUEGRASS (Poa CANADA BLUEGRASS
(Poa nemoralis). pratensis); ROUGH-STALKED (Poa compressa) .
MEADOW GRASS (Poa trivi-
alis).

Silky pubescence of the Silky pubescence of the veins wanting or but slight.
veins mostly present and

prominent.
Apex of the glume slen- Apex of the glume acute. Apex of the glume broadly
derly pointed or nar- flaring.

rowly flaring.
Intermediate veins indis- Intermediate veins dis- Intermediate veins indis-
tinct. tinct. tinct.

Rachilla segment pubes- Rachillasegment smooth, not exceeding half the length
cent, often more than of the glume.
half the length of the
glume.

Poa triflora Ehrh. (P. flava L., P. serotina Ehrh.).
FOWL MEADOW GRASS, FALSE REDTOP.

Spikelets 2-4 flowered; florets 2-2 mm.long, lanceolate or ovate-lanceolate as
viewed from the back, broadly keeled and strongly arched at the back, light brown
and usually strongly tinged with yellow above the middle, sometimes purplish,
margins of the glume narrowly infolded below the middle or quite to the apex,
which is hyaline-edged, expanded but scarcely flaring; intermediate veins indis-
tinct; keel and marginal
veins silky pubescent below
the middle; basal web
slight; palea nearly or quite
equal to the glume, finely
hispid-ciliate on the keels,
which are mainly covered
by the glume margins in the
lower florets; rachilla seg-
ment slender, glabrous or
sometimes slightly scabrous, from one-fourth to one-half or two-thirds the length of.
the glume; aborted floret of the sterile rachilla segment often prominent and nearly
as long as the rachilla segment; grain 1 mm. long, comparatively robust and smooth,
scarcely keeled or grooved, semitranslucent. (Fig. 8.)

Fic. 8.—Seeds of fowl meadow grass (Poa triflora): a-c, back
views; d and e, side views; /-h, front views; h, a terminal floret.

Most, if not all, of the seed of P. trzflora on the market appears to
be of foreign production. The samples examined have proved to be
the worst found among the bluegrasses. It is probable that a better
grade of seed could be secured from the natural meadows in this coun-
try where this species often constitutes the principal grass. The
seeds of P. triflora are very similar to those of Canada bluegrass and
wood meadow grass.

28

THE SEEDS

OF THE BLUEGRASSES.

The principal distinguishing characters of the three kinds are as

follows:

FOWL MEADOW GRASS
(Poa triflora).

Seeds 2-253 mm. long.

Seeds mostiy narrower at
the apex than at the cen-
ter.

Seeds usually yellowish at
the apex.

Intermediate veins usually
evident but indistinct.

Pubescence of the veins
and the web often pres-
ent in commercial seed.

Rachilla segment mostly
smooth,sometimesslight-
ly rough, often two-
thirds the length of the
glume.

CANADA BLUEGRASS
( Poa compressa).

Seeds 2-25 mm. long.

Seeds mostly broader at the
apex than at the center
or base.

Seeds not yellowish at the
apex.

Intermediate veins indis-
tinct or more commonly
not evident.

Pubescence of the veins and

the web mostly absent in
commercial seed.
Rachilla segment smooth,
not exceeding one-half of
the length of the glume.

WooD MEADOW GRASS

(Poa nemoralis).

Seeds 23-3 mm. long.

Seeds narrower or not
broader at the apex than
at the center.

Seeds sometimes yellowish
at the apex.

Intermediate veins indis-
tinet.

Pubescence of the veins
usually present in com-
mercial seed.

Rachilla segment pubes-
cent or sometimes only
rough, oftenthree-fourths
the length of the glume.

The name fowl meadow grass is often applied, both by seedsmen
and by writers upon grasses, to Panicularia nervata.

Poa arachnifera Torr.

TEXAS BLUEGRASS.

Spikelets 4 or 5 flowered; florets +6 mm. long, narrowly lanceolate, acuminate,

straw colored or light brown; glume strongly keeled quite to the apex and somewhat
arched; margins narrowly infolded below and becoming broadly hyaline above the
middle, not widely flaring at the apex; marginal and keel veins strongly pubes-

Fic. 9.—Seeds of Texas bluegrass (Poa arachnifera): a and b, back views, seeds showing the long
hairs of the web; c and d, side views; e-g, front views; g, a terminal floret.

cent with long, silky hairs; basal web copious, often twice as long as the floret,
very persistent; surface between the veins glabrous, the keel hispid-ciliate above the
middle; palea from three-fourths to four-fifths the length of the glume, its keels
more or less exposed, silky pubescent to the middle and hispid-ciliate at the apex;
rachilla segment varying from about one-sixth to one-third the length of the glume,
glabrous; aborted floret of the sterile rachilla segment minute; grain slender, 13-3
mm. long, oblong-fusiform, nearly opaque, distinctly grooved and keeled. (Fig. 9.)

DESCRIPTIONS OF SPECIES. 29

Texas bluegrass seed in commerce is unrubbed, and as the silky
pubescence and web are very persistent they are always present. The
hairs are so long and copious that the seeds cling in loosely matted,
woolly bunches, and thus are easily distinguished :
from all the other commercial Poas. (Fig. 10.)

Poa annua L.

ANNUAL MEADOW GRASS.

Spikelets 3-5 flowered; florets 15-3 mm. long, ovate or
ovate-lanceolate and relatively robust, strongly keeled and
arched at the back, more or less densely pubescent, light
brown or dark brown and often purplish or yellowish;
margins of the glume very narrowly infolded below the
middle, thin and broadly hyaline above the middle inthe Fig. 10.—A cluster of Texas
lower florets, flaring, gaping, or infolded at the apex; inter- bluegrass seeds matted by
mediate veins usually distinct as narrow ridges extending — *& webby fibers.
from the base to the margin of the apex, glabrous or pubescent; marginal veins
and keel densely soft-pubescent below the middle; surface between the veins some-
times more or less pubescent at the base; web wanting; palea somewhat shorter than
the glume, except in the terminal floret; keels of the palea coarse and prominent,
mostly exposed, usually arched forward and exposed to side view in florets having a
well-developed grain, often contracted toward the rachilla segment at the base, silky
pubescent from near the base nearly to the apex; rachilla segment glabrous, from
one-fourth to one-third the length of the glume, aborted floret of the sterile rachilla
segment minute; grain 1-13 mm. long, robust, distinctly granular, keeled and grooved,
slightly translucent. (Fig. 11.)

The seed of Poa annua is not in the trade and is not apt to become
mixed with the commercial bluegrass seeds. It may be readily distin-
guished from the common commercial species of Poa by its abundant

fame 29
ge

Sara?

teins

Fic. 11.—Seeds of annual meadow grass (Poa annua): a and b, back views; c-e, side views; j-i, front
views; 7, a terminal floret.

pubescence, arched and silky pubescent keels of the palea, and robust

form. The seed most closely resembles that of Poa alpina, from which

it is distinguished in individual seeds by its distinct intermediate veins

and prominent, arched, and silky pubescent but not hispid-ciliate palea

keels.
Poa alpina L.

ALPINE MEADOW GRASS.

Spikelets 3-6 flowered; florets 23-33 mm. long, ovate-lanceolate or obovate, the
uppermost lanceolate, broadly keeled, arched, acute, or obtuse, ight brown, some-
times purplish, and often yellowish tinged at the apex; margins narrowly infolded
below the middle and becoming broadly hyaline at the apex; intermediate veins

30 THE SEEDS OF THE BLUEGRASSES.

indistinct or evident only below the middle; keel and marginal veins silky pubescent
below the middle or higher on the keel, which is hispid at the apex; surface between
the marginal veins and keel appressed pubescent at the base; web wanting; palea
nearly or quite equal to the glume, its keels not arched as in Poa annua, slightly
silky pubescent below the middle and hispid-ciliate above; rachilla segment glabrous,
_varying from no longer than wide to one-third the length of the glume; aborted
floret of the sterile rachilla segment minute; grain 14 mm. long, keeled and grooved,
semitranslucent, dark reddish brown, granular. (Fig. 12.)

Fig. 12.—Seeds of alpine meadow grass (Poa alpina): a and b, back views; c-e, side views; /-h, front
views; h, a terminal floret.

The seed of Poa alpina is not on the market and is not likely to be
found in commercial seeds. Individual seeds of P. alpina closely
resemble those of P. annua, but are to be distinguished by the indis-
tinct intermediate veins of the glume, the variable rachilla segment,
and especially by the keels of the palea, which are slenderer, not
arched, less pubescent, and strictly hispid-ciliate above. The plant is
alpine and occurs in the northern part of the United States as far
west as Colorado, in Canada and Alaska, and in Europe and Asia.

Poa sudetica Haenke.

Spikelets 2 or 3 flowered; florets 3-4 mm. long, lanceolate or ovate-lanceolate;
apex acute or acuminate; glume somewhat arched and strongly keeled at the back,
light brown or dark brown, sometimes tinged with purple; margins of the glume
narrowly infolded below the middle, narrowly hyaline-edged above the middle and
not flaring at the apex; all the veins distinct, never silky pubescent, usually hispid;

Fic. 13.—Seeds of Poa sudetica: a and b, back views; -c-e, side views; f and g, front views; g,a terminal
floret.

general surface scabrous or sometimes glabrous; web not present; palea equaling or
somewhat exceeding the glume and often separated from it at the apex in florets
having a well-developed grain; keels of the palea hispid-ciliate, mostly exposed and
more or less evident from the side; rachilla segment varying from one-fifth to one-
third or even one-half the length of the glume, glabrous or scabrous, sterile rachilla

DESCRIPTIONS OF SPECIES. ol

segment tapering to the apex, the aborted floret usually minute, but sometimes con-
spicuous and nearly equal to the rachilla segment; grain about 2 mm. long, robust,
light brown, slightly keeled and grooved, semitranslucent. (Fig. 13.)

This is a European species not found in the American market.
Panicularia spp.

Owing to the fact that Panicularia nervata is sometimes sold as fowl
meadow grass, a description of its seed is presented. A description
of the closely allied P. americana, which is often associated with
P. nervata, is added as an aid in comparing the two species.

Panicularia nervata (Willd.) Kuntze.
NERVED MANNA GRASS, SOMETIMES CALLED FOWL MEADOW GRASS.

Florets 1-13 mm. long, robust, ovate (obovate with reference to the plant), light
brown, purplish and sometimes greenish when immature; glume rounded at the
back, prominently seven-veined, its margins
somewhat infolded at the base and not flaring at
the apex, which is sometimes narrowly hyaline;
surface smooth, except the veins, which are
sometimes scabrous; palea equal to or sometimes
longer than the glume, broad, the keels exposed,
prominent and nearly meeting at the rounded
and sometimes slightly notched apex, usually F!¢. 14.—Seeds of nerved manna grass
scabrous above the middle; rachilla segment one- ot sae Rei Gand by pacleaia
fifth to one-fourth the length of the glume, sub- er
cylindrical and scarcely expanded at the apex, the terminal one somewhat longer
than the others and tipped by a minute, aborted floret; grain loosely held by the
stifish glume and palea, obovate, slightly flattened, }-1 mm. long, smooth, some-
what polished, very dark brown or black, sometimes slightly translucent. (Fig. 14.)

Panicularia americana (Torr.) MacM.
REED MEADOW GRASS, WATER MEADOW GRASS, TALL MANNA GRASS.

Florets 3-33 mm. long, elliptical-oblong as viewed from the front or back, some-
what spindle-shaped as viewed from the side, obtuse at the apex, brown, or purplish
before complete maturi-
ty; glume rounded at the
back, distinctly seven-
veined, its margins nar-
rowly infolded at the
base and not flaring at
the apex; surface smooth
Ry between the scabrous
d a veins; palea equal to the

"glume, concaye, its keels
exposed, nearly meeting

Fic. 15.—Seeds of water meadow grass (Panicularia americana): a,b, at the apex, very finely
and ¢, back, side, and front views of seeds: d, grain. x :

hispid-ciliate; rachilla
segment one-fifth to one-fourth the length of the glume, subcylindrical, somewhat
expanded at the apex, that of the terminal floret slightly longer and tipped by a
minute, aborted floret; grain broadly oblong, 13-2 mm. long, somewhat flattened,
very dark brown, slightly translucent, smooth, and somewhat polished when fully
developed. (Fig. 15.)

32 THE SEEDS OF THE BLUEGRASSES.

WEED SEEDS COMMONLY FOUND WITH COMMERCIAL BLUE-
GRASS SEEDS.

The following weed seeds are those most frequently found with the
various kinds of bluegrass seed.

Bursa bursa-pastoris (L.) Britton.
SHEPHERD’S-PURSE.

Seeds 3-1 mm. long, oval-oblong, one extremity often pointed by the whitish tissue
of the scar, flattened with rounded edges; faces similar and usually presenting two shal-
low grooves; color yellowish or reddish brown,
usually darker near the scar; surface nearly
smooth; endosperm absent; embryo curved
upon itself, the cotyledons incumbent; seeds
Cc developing a coat of transparent mucilage
when placed in water. (Fig. 16.)

Seldom found abundantly, but occurring
frequently in all of the commercial bluegrass

Fig. 16.—Seeds of shepherd’s-purse (Bursa
bursa-pastoris): a, side view; b, edge view;
c, Natural size of seeds. seeds.

Lepidium virginicum L.
PEPPERGRASS.

Seeds 14 mm. long, much flattened, ovate with one edge straight and thicker than
the other, the curved edge narrowly margined, the mar-

gin usually hyaline and broadest at the broad end of the eons
seed; faces similar, each nearly crossed lengthwise by a Ree

curved groove; scar at the small extremity, marked by eee
a small, whitish tissue; surface smooth, dull, and red- Cig

dish yellow; endosperm wanting; embryo curved upon eee
itself, the cotyledons accumbent; seeds developing a i
copious coat of transparent mucilage when placed in view; b, edge view; ¢, natural
water. (Fig. 17.) size of seeds.
Frequently found in home-grown seed and sometimes very abundant, especially in
poorly cleaned seed.
Cerastium vulgatum L.

MOUSE-EAR CHICKWEED.

Seeds about 4 mm. long, flattened but not thin, rounded or triangular, the broad
edge rounded, the narrow edge notched; surface roughened by small tubercles
or very short ridges, dull, and reddish-

0, @ brown; embryo cylindrical, curved about
o ee the endosperm, its extremities nearly

5 meeting at the notch in the seed coat.
(Fig. 18.)
Fig. 18.—Seeds of mouse-ear chickweed (Ce- Found irequently; sometimes abundant in

rastium vulgatum): a, side views; 6, natural poorly cleaned seed.
size of seeds.

Alsine media L.
COMMON CHICKWEED.

Seeds circular-ovate, about 1 mm. in diameter with little variation in size, flattened
with plane faces and flattened edges; scar in a small notch in the edge; surface dull,
slightly tubercled, the tubercles in rows on the edges and in more or less evidently

WEED SEEDS FOUND WITH BLUEGRASS SEEDS. Bal

concentric rows on the similar faces; color brown, or reddish in immature seeds:
embryo cylindrical, curved about the endosperm, its extremities nearly meeting at
the sear. (Fig. 19, a.)

Alsine media is very common in the United States, but is so low-growing that the
American method of seed stripping prevents the occurrence of its seeds in abundance
in commercial bluegrass seeds. Its seeds
are common in European bluegrass seeds,

€- ¢
particularly those of rough-stalked meadow ©
3
grass. A
fo)
<i @
Alsine graminea (L.) Britton. ¢
Fie. 19.—Seeds of chickweeds: a, Alsine me-
Seeds similar to those of Alsine media, ex- dia; b, A. graminea; c, natural size of seeds.

cept in form and surface markings; usually ~
circular or oval; faces and edges somewhat rounded, finely roughened by short, inter-
lacing ridges which are arranged more or less concentrically on the faces and
parallel on the edges; surface dull; color grayish-brown, immature seeds reddish.
(Fig. 19, bd.)

Not found in American seed; frequent, although not abundant, in European seed.

Carduus arvensis (L.) Robs.

SS
) 4 CANADA THISTLE.
Seeds (akenes) 2-3 mm. long,

oblong-lanceolate, flattened with
obtuse edges, slightly ridged along
each face, straight or curved edge-
wise, sometimes facewise; apex
truncate, often obliquely so, con-
cave with a ring-like border; corolla scar represented by a central, conical projection;
surface dull and mostly smooth, sometimes with several narrow, longitudinal grooves;
color brown, the apical margin usually lighter
and sometimes yellowish. (Fig. 20.)

Prickles of Canada thistle and horse nettle
(Solanum carolinense) often occur in certain
bluegrass seeds. While the presence of the
former is significant with respect to adultera-
tion, the two kinds are apt to be confounded.

The prickles of Canada thistle are 2-6 mm.
long, very slender, yellowish, usually expanded
and laterally flattened at the base, which con-
sists of a portion of the leaf tissue and is darker
colored than the rest of the prickle, somewhat
rounded or angular in form and jagged-edged.
(Fig. 21, cand d).

The prickles of horse nettle (Solanum caro- Fie. 21.—Prickles often found with blue-

Fria. 20.—Seeds of Canada thistle ( Carduus arvensis): a, well-
matured seeds; 6, natural size of seeds; c,ashriveledseed.

linense) are coarser, 4-8 mm. in length, light pres seed cand) Horse merle (Sola
yellow in color, usually not darker at the base CT Ea tanga Sea eA oh
/ 2 ’ ide size; c and d, Canada thistle (Carduus
They are produced on the stems and the coarse arvensis) enlarged and natural size; land
midribs of the leaves, and on breaking off have 2, characteristic forms of the bases of
a transversely flattened scar. They occur fre- VERSE NOU SHOS Cie ypule aes

quently in samples of Kentucky-grown Poa pratensis and are easily mistaken for
those of Canada thistle. (Fig. 21, a and b.)

Matured seeds, shriveled seeds, and prickles from the leaves and stems of Canada
thistle are frequently found in Canada bluegrass seed. The presence of the prickles

34 THE SEEDS OF THE BLUEGRASSES.

in the more expensive kinds of bluegrass seed indicates the probable use of Canada
bluegrass seed as an adulterant. These prickles have been found, however, in rough-
stalked meadow grass seed in which no trace of Canada bluegrass seed appeared.
Owing to the troublesome nature of Canada thistle. care should be taken not to
introduce its seeds with those of the bluegrasses.

2

Taraxacum taraxacum (L.) Karst.
DANDELION.

% # Seeds (akenes) 3-4 mm. long, including the per-
sistent base of the beak, which forms the pointed
- F ge apex of the seed, lance-shaped or broadly so,
b straight or curved, flattened or slightly four-
angled with similar faces, barbed in the upper,
Fic. 22.—Seeds of dandelion (Tarara- broader half; teeth directed toward the apex,
cum taraxacum): a, side views; >, nat- prominent on the edges and arranged in about
ural size of seeds. P 9
five rows on each face, which has two slender
grooves with three rows of teeth between them; surface dull; color light brown or
dark brown. (Fig. 22.)
Occurring occasionally in both American and European seed, these seeds have
appeared most frequently in Kentucky bluegrass and rough-stalked meadow grass
seeds.

Matricaria inodora L.
SCENTLESS CAMOMILE.

Seeds (akenes) 14-2 mm. long, slender or
robust, oblong with obtuse extremities, taper-
ing somewhat from the truncate apex to the
base, slightly flattened; faces dissimilar, one
having three prominent, longitudinal ribs FiG. 23.—Seeds of scentless camomile
joined at the apex, the lateral ribs and a partial eee GAM a ie a mm!
one joined to them at the apex appearing on
the opposite face, which also presents two small cavities separated by the partial
ridge; surface between the ridges transversely roughened, dark brown or black and
darker than the brown or yellowish ridges. (Fig. 23.)

Found only in foreign-grown seed, chiefly in rough-
stalked meadow grass and wood meadow grass seeds.

J i Hieracium sp.
a HAWKWEED.
— Seeds (akenes) 1-3 mm. long, cylindrical, pointed at
b the base; apex truncate, bearing a small tuft of short,

whitish, marginal bristles (the remnants of the pappus
Fic. 24.—Seeds of hawkweed bristles); surface lightly ten-ridged lengthwise; color
(Mieraciumsp.): a, side views; brown or black, reddish in immature seeds. (Fig. 24.)
Ummaturalisize ohsceds. Found most frequently in wood meadow grass seed.
The seeds of several species of hawkweed, occurring in both America and Europe,
are practically indistinguishable. Specific determinations can not be made by exam-
ination with a lens. The troublesome character of orange hawkweed (Hieracium
aurantiacum), whose seeds are 14-1? mm. long, justifies care in the use of seed
containing seeds of any species of hawkweed.

4

WEED SEEDS FOUND WITH BLUEGRASS SEEDS. 35

Anthemis cotula L.
DOG FENNEL, MAYWEED.

Seeds (akenes) cylindrical, broadly club-shaped, 13-2 mm. long, straight or
curved; surface dull and usually roughened by
many small tubercles more or less distinctly
arranged in ten rows, indistinctly few-tubercled
or nearly smooth, but commonly more or less
evidently ten-ribbed; base tipped by the rounded,
whitish scar; apex rounded or slightly pointed;
color varying from light to dark brown. (Fig. 25.) gig. 95.—seeds of dog fennel(Anthemis

Found occasionally, but never abundantly, in eotula): a, side views; b, natural size
both American and European bluegrass seed. of seeds,

Chenopodium album L.
LAMB’S-QUARTERS, PIGWEED.

Seeds nearly circular, lens-shaped, with blunt edges, 1-1} mm. in diameter, occur-
ring in commercial seeds as free seeds or as fruits, the seeds proper being invested by
the thin pericarp; free seeds jet black, smooth
or nearly so, and highly polished; scar occu-
pying a curved groove extending from the cen-
ter to the edge of one face and usually evident
as a light-colored line; fruits only slightly
larger than the seeds, mostly gray or black and
dull; pericarp wall often broken away, expos-

ing theshining black surface of theseed; again,

Fig. 26.—Seeds of lambs quarters (Chenopo- this wall and the seed coat are often. broken

dium album): a, various forms of seeds; 0, : : ee: 2

Bien ciecloneeeds: exposing the yellowish or whitish embryo and

endosperm; embryo cylindrical, occupying

the border of the seed and surrounding the endosperm, its extremities almost meet-

ing, the tip of the caulicle occupying an extension of the seed coat at the edge beside
the sear. (Fig. 26.)

Found chiefly in Kentucky bluegrass and Canada
bluegrass seeds, but not frequently and never abun-
dantly.

Plantago lanceolata L.

RIB-GRASS, BUCKHORN, ENGLISH PLANTAIN.

Seeds oval-oblong, 13-3 mm. long, flattened, one
face convex, the other having a deep groove and Fie. 27.—Seeds of rib-grass (Plan-
rounded, infolded edges which scarcely meet at one —‘@g0 lanceolata): a, front and back
end; surface smooth or slightly uneven, shining in eae Oi seeds.g0; Delunalsizerds
fresh seed, brown or somewhat amber-colored; scar sis”
situated at the center of the grooved face; embryo straight, in the center of the
endosperm, usually evident through the somewhat transparent endosperm and seed
coat. When placed in water the seeds develop a coat of transparent mucilage.
(Fig. 27.)

Small seeds are found to some extent in both American and European seed; more
commonly in Kentucky bluegrass than in Canada bluegrass seed.

36 THE SEEDS OF THE BLUEGRASSES.

Rumex crispus L.
CURLED DOCK.

Seeds (akenes) 13-23 mm. long, triangular with equal faces and broadly ovate-
lanceolate; color dark reddish brown; surface smooth, polished; apex acute; base
obtuse, contracted, and ey truncate at the scar; edges narrowly margined;

faces longitudinally concave in poorly developed

seeds; true seed coat thin; embryo cylindrical, rest-

$ ing in the center of one face of the endosperm;

caulicle pointing to the base of theakene. (Fig. 28.)

4 Found occasionally, especially in Kentucky biue-

grass and in Canada bluegrass seeds; small, imper-

Fie. 28.—Seeds of curled dock (Ru- fectly developed seed more commonly found than

Bee ee eras large, heavy seed. Their sharply three-angled,

beechnut-like form distinguishes them from other

impurities, except one or two other kinds of dock. The docks are destructive weeds,
and care should be taken to prevent the sowing of their seeds.

FAy

Rumex acetosella L.

SHEEP’S SORREL, SORREL.

Seeds (iruits) acutely oval, three-angled, with equal faces, 1-1} mm. long; repre-
sented in commercial seed by the seed-like akene only or by the akene covered by
the thin, closely fitting perianth segments, which are six in number, three broad
ones covering the sides of the

akene and three small ones cover- es

ing the angles at the base; covered *
Q

by the perianth, the seeds are °

finely roughened, dull, and red- . .

dish brown; venation of the three
broad segments evident; small
segments at the basal angles oiten
broken away; akenes but slightly
smaller than when covered by the perianth, bluntly three-angled; surface smooth,
somewhat polished, reddish brown or wine colored, often semitranslucent; angles
dark at the apex; internal structure essentially the same as in Rumex crispus.
(Fig. 29.)

_One of the commonest impurities in commercial
seed, found in all seed of the cultivated bluegrasses.

Fie. 29.—Seeds of sorrel (Rumex acetosella): a, b, and e,
seed enveloped by the perianth; d, seed with perianth
removed; ¢, natural size of seeds.

Veronica arvensis L.

CORN SPEEDWELL.

Seeds 3-3? mm. long, flattened and thin, more or
iat Seeds or eonl speedwelin ess comikirls oval, plane or sometimes curved face-

( Veronica arvensis): aandb,front wise; center of the inner face marked by the relatively

views; ¢, back view; d, natural large, raised chalaza, which is united by a narrow

aot eed ridge (the raphe) to the scar on the edge of the
smaller extremity of the seed; external face slightly ridged longitudinally, indicat-
ing the position of the embryo, which is surrounded by the endosperm; surface dull,
finely roughened by somewhat radially-disposed ridges, and reddish yellow. (Fig.
30. )

gh

uth wy ay

Ss adh ae Le

lah

WEED SEEDS FOUND WITH BLUEGRASS SEEDS. 34
Found in bluegrass seed of various species, especially common in seed of Kentucky
bluegrass. The relatively prominent chalaza and the radially uneven surface dis-
tinguish them from the seed of the closely allied Veronica
peregrina, which sometimes occurs in commercial seed.

Juncus tenuis Willd.”

° e es

b
rh
Seeds very minute, about 4 mm. long, broadly spindle-
shaped, the extremities usually slightly curved; surface Fi. 31.—Seeds of slender rush
(as seen under a lens) nearly smooth; color reddish (Juncus tenuis): a, seeds en-
Sees : : larged; 6, natural size of
yellow, darker at the extremities, which sometimes bear ....4.
a small white tissue. (Fig. 31.)
Often quite abundant in poorly cleaned Kentucky bluegrass seed, sometimes cling-
ing in bunches of several seeds each.

SLENDER RUSH.

Juncoides campestre (L.) Kuntze.

FIELD RUSH.

6
a 4 Seeds 14-13 mm. long, oval, not flattened, the ex-
ce tremities unequally pointed, the basal extremity turned
8 slightly to one side and consisting of soft white or
b yellowish tissue; a narrow and often indistinctly de-

Tr eae of Geld wate CUE fined whitish ridge extends from the base to the apex;
Een Caapesic\a a= dificrent body of the seed wine-colored and semitranslucent or
views; b, natural size of seeds. grayish. (Fig. 32.)

Found frequently in the seed of wood meadow
grass and of the Poa sudetica of European origin.

Juncoides albida DC

WOOD RUSH.

Seeds 1-14 mm. long, narrowly oval, not flattened; base without an appendage of
soft tissue; apex more acutely pointed than the base;
a distinct brown or reddish brown ridge joins the base
and apex; body of the seed reddish brown or wine-
colored, often semitranslucent. (Fig. 33.)

Found in various species of European-grown blue-
grass seed. The usually smaller size, absence of the
basal appendage, and more distinct and constant oO ee aes ze Af Spsodruah Chink:
dish-brown lateral ridge serve to distinguish these — oides athida): a, different views:
from the seeds of Juncoides campestre. b, natural size of seeds.

Carex cephalophora Muhl.

OVAL-HEADED SEDGE.

Seeds (akenes) 13-2 mm. long, lens-shaped and broadly ovate, contracted at the
base and tipped at the apex by a conical appendage (the base of the style); surface
smooth and dull; color varying from light to dark brown; apical appendage often
broken away in seeds found in commercial samples; perigynium broadly ovate-
lanceolate, plano-convex, the tapering extremity usually rough-edged and notched at

38 THE SEEDS OF THE BLUEGRASSES.

the apex; surface sometimes slightly grooved or ridged lengthwise, otherwise smooth;
color varying from light brown to greenish or dark brown. (Fig. 34.)

Seeds of sedge (Carex) are found in
both American and European bluegrass
seed. Owing to the wide area of their
production, the seeds of various species
of Carex occur in commercial blue-
grass seed. The seeds of Carex are
fruits (akenes) and occur free or in-
closed within a sac-like covering (the

; perigynium). Carex cephalophora is
Fic. 34.—Seeds of sedge (Carex cephalophora): a, seeds th : .
gee are e species most commonly found in

inclosed by the perigynium; b and c, seeds with 2

perigynium removed; d, natural size of seeds. Kentucky bluegrass seed.

ERGOT OCCASIONALLY FOUND IN COMMERCIAL
BLUEGRASS SEED.

Claviceps purpurea (Fr.) Tul.

ERGOT.

This is a fungus growth affecting the grain (caryopsis) of
many grasses. It is very common in the seed of redtop and
other species of Agrostis, and occasionally occurs in bluegrass
seed. The grain of the seed becomes elongated, extending »,, 85.—Ergot (Clave
beyond the glume and palea, attains about twice the length of — ceps purpurea) of Ken-
the glume, and is club-shaped, straight, or, more commonly, — tucky bluegrass: a,en-
somewhat curved. It is black, dull, and somewhat grooved /#78¢4; >, natural size.
lengthwise. (Fig. 35.)

O