The identification of grasses by their vegetative characters

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BULLETIN No. 461

Contribution from the Bureau of Plant Industry
WM. A. TAYLOR, Chief

Washington, D. C. Vv = January 19, 1917

THE IDENTIFICATION OF GRASSES BY THEIR
VEGETATIVE CHARACTERS.

By LYMAN CARRIER,
Agronomist in Pasture Investigations, Forage-Crop Investigations.

CONTENTS.
Page. Page.
MMPROGUCHION sons ce etinet eee eacnee ete anaces 1 | Detailed descriptions of forty-eight seedling
What is meant by the term ‘‘grass’’........- Di et OTUSSOS aera Oe Wa eh rose Niall mp ich 9
Characteristics of grasses before the blooming Identification of small-grain seedlings.......- 26
SAR Ch area ama resaere at ae renters aM EE 2 | Analytical key to small-grain seedlings..--.. 27
How to use the key in identifying grasses... . 4 | Detailed descriptions of eight small-grain
Analytical key to grass seedlings............. Gril SCOGUING Sie once meine secs que leita alsa acter 27
INTRODUCTION.

It is often desirable to identify grasses by their vegetative char-
acters. The usual botanical classifications based on the structure of
the flowering parts are not useful for this purpose. Any mention
of the leaves which may be included in botanical descriptions is
usually for the purpose of confirming an identification. In lawns
and pastures the best grasses are seldom allowed to reach the flower-
ing stage, and some grasses change so materially in appearance as
they reach maturity that it is difficult to see a resemblance to the
young plants in those that have headed.

There have been previous attempts to work out keys for identi-
fying young grasses, especially those of McAlpine,? of Ward,? and
of Percival.2 Stebler and Schroter* have described and illustrated
fully the vegetative characters of the most common hay and pasture

1 McAlpine, A. N. How to know grasses by the leaves. In Standard Cyclopedia of
Modern Agriculture, v. 6, p. 153. 1890.

2 Ward, H. M. Grasses. 190 p., illus. Cambridge, 1901.

3 Percival, John. Agricultural botany. 798 p., illus. London, 1900.

£Stebler, F. G., and -Schréter, Carl. The best forage plants. 3 v. in 1, illus, pl.
London, 1889.

61167°—Bull. 461—17——-1

3

9 BULLETIN 461, U. S. DEPARTMENT OF AGRICULTURE.

grasses. Lewton-Brain' has described the leaf anatomy of many
British grasses.

The general plan of classification used in this bulletin follows some-
what that of Percival, but it is enlarged to include about three times
the number of grasses described by him.

- WHAT IS MEANT BY THE TERM “GRASS.”

In this discussion the term “ grass” is restricted entirely to those
plants which botanists group in the family Graminee or Poacez
and does not include the clevers and some other forage plants which
are often classed agriculturally under the term “grass.” The true
grasses are recognizable by the following characters: Stems jointed,
usually hollow; leaves in two ranks on opposite sides of the stem,
each consisting of two parts, the blade, usually narrow and elon-
gated, and the sheath, or basal portion, tubular and enwrapping
the stem, its margins free or rarely grown together; leaf nerves
parallel; at the junction of the sheath and blade a small membranous
appendage, the ligule, which is sometimes wanting.

The plants which are most likely to be mistaken for grasses are the
sedges (fig. 1), characterized by 3-ranked leaves on a solid, usually
3-angled stem, and the rushes (fig. 2), distinguished by solid stems,
tubelike closed sheaths, and cylindrical or straplike leaves, neither
folded nor rolled in the bud, and without ligules.

CHARACTERISTICS OF GRASSES BEFORE THE BLOOMING STAGE.

Grasses, like other flowering plants, may be considered as made up
of roots, stems, leaves, and flowering parts. The natural classifica-
tion of grasses is based mainly on the flowers and fruits, but the other
organs show much variation in structure; indeed, sufficient to identify
most grasses from their vegetative parts alone. :

Roots—The true roots of grasses are very slender and often much |
branched. They vary less than other organs, however, so that it is
rarely possible to identify a grass from its roots alone, at least from
the gross structure.

Stems.—Apart from the erect stems of grasses, which are usually
flower bearing, many species have stems of a different sort. In some
cases these are creeping, leaf bearing, and often rooting at the joints.
Such stems are termed stolons. Many grasses have underground
stems. These are jointed, bear scalelike reduced leaf sheaths, and are —
usually horizontal and coarser than roots. Such underground stems
are termed rootstocks or rhizomes. |

1 Lewton-Brain, Lawrence. On the anatomy of the leaves of British grasses. Jn Trans. —
Linn. Soc., London, s. 2, Bot., v. 6, pt. 7, p. 315-359, pl. 36-40. 1904.

IDENTIFICATION OF GRASSES. 3

Leaves (fig. 3).—A grass leaf consists of two principal parts, the
sheath or tubular basal portion which incloses the stem, and the
_ blade, nearly always long, narrow, and most commonly flat. The
sheaths are usually cylindrical in form, but in some grasses they are
laterally compressed, forming a keel at the back, in which case they
are described as compressed. In some grasses the nerves of the
sheaths are prominent, in others scarcely noticeable. A few grasses
have distinctively colored sheaths, the coloration being especially
noticeable in the portion below ground. At the junction of the
sheath and the blade are structures that are very useful in identify-
_ ing grasses not in blossom. On the inside of the sheath is a small

Fic. 3.—Different parts of a
grass: A, Blade; B, ligule;
C, collar; D, sheath; #,

Fig. 1—A common sedge. Fig, 2.—A Juncus. shoot or bud leaf.

organ, the ligule, apparently a continuation of the lining of the
sheath and usually very thin in texture. It usually consists of a thin.
semitransparent membrane, but sometimes it is a mere fringe of
hairs, and only in rare cases is it wholly absent. The ligules of some
grasses are wider than the sheaths and continuous with the hyaline
margins. Owing to its wide variation in form, the ligule is one of
the most dependable of characters for identification. Several special
terms are necessary to describe these forms: Entire, when there are
no notches or indentations along the margin; lacerate, when the
margin is much cut; truncate, when the apex is apparently cut off
squarely; acute, when the apex terminates in a sharp point; and
ciliate, when the margin is fringed with hairs. Other terms, such
as “toothed along the margins,” or “hairy on the back,” are self-
explanatory.

4 BULLETIN 461, U. S. DEPARTMENT OF AGRICULTURE.

The collar is a narrow band marking the place where the blade |
and the sheath join. It is often scarcely differentiated, but usually |
has a different color from either the blade or the sheath. In some §*

cases the collar is a continuous band extending from one margin of

the leaf to the other, but in others it is divided into two parts by | o

the midnerve. ‘The margins of the collar in some grasses are wavy,
in others straight; some are hairy, others entirely glabrous or hairless.
In some grasses one side of the collar is higher than the other, giving
it a spiral appearance.

The auricles are earlike or clawlike appendages projecting from |)

the collar or the angles at the top of the sheaths in a few grasses.

They may be small or large, hairy or free from hairs. Often they
clasp the stems more or less, especially when young, but as they

become older and dried they may turn away from the stem. Only
- the narrow clawlike auricles are considered in the analytical key. _
The flowering parts are not used in this classification. If the
grass has reached the blooming stage it can be more easily identified
by using one of the many books on the subject.
The word glabrous is used to mean free from hairs.

HOW TO USE THE KEY IN IDENTIFYING GRASSES.

The analytical key (pp. 6-9) is composed of pairs of opposing
statements. The first statement of each pair is designated by a letter,
A, B, C, etc.; the second one has the same letter as the first, but
repeated, as AA, BB, CC, etc. The statements constituting each
pair may be close together, as “A. Auricles narrow and clawlike, |
clasping the stems more or less,” and “AA. -Auricles wanting, or at
least not narrow and clawlike,” or they may be separated as “ B. Col-
lar hairy,” and “BB. Collar not hairy.” If a specimen does not
agree with the first statement, all intervening headings should be
passed over at once until the corresponding second statement which ~
does apply is reached. :

One of the best ways to learn to use this key is to get specimens
of young grasses and endeavor to trace them. Take, for example,
orchard grass. The first thing that must be done is to determine
whether the leaf is folded (fig. 4, 4) or rolled (convolute; fig. 4,
B and (@) inthe bud. This is best done by cutting across the young
shoot with a sharp knife and examining it with a lens. Another
method of determining this point is to strip off the leaves carefully
until the youngest is exposed and then examine with a lens. With
the larger grasses it is easy to decide whether the leaves are folded
or rolled in the bud, but with the finer sorts, such as the bent grasses
or the fescues, it is sometimes difficult. The leaf in the case of
orchard grass is folded in the bud, so it will come in Group I.
The first line of the key, marked “A,” reads -“ Auricles

IDENTIFICATION OF. GRASSES. 5

- narrow and clawlike, clasping the stem more or less.” As orchard
_ grass does not have clawlike auricles, pass on to the line “AA,” which
reads “Auricles wanting, or at least not narrow and clawlike.” The
next line after “AA,” marked “ B,” reads “ Collar hairy.” Orchard
grass does not have a hairy collar; so, pass over the intervening sub-
jects to line “ BB. Collar not hairy.” The next line, “C. Sheaths
below ground bright yellow,” does not apply to this grass; so, pass
on to “CC. Sheaths below ground not yellow.” The next line, “ D.
Blades narrow and bristlelike, but with prominent veins on upper
surface,” does not apply; so, pass on to “ DD. Blades flat; nerves not
prominent.” The next line, “ E. Blades broad without white lines
‘along midnerve by transmitted light; tip of blade taper pointed,”
applies, and here is also given the name of the grass.

The number before the common name of the grass refers to the
number given this grass in the general description following the key.
As there are several hundred grasses and this key includes but 56,

Fie. 4.—Different arrangements of leaves in the buds: A, Folded; B and CO, rolled or
convolute.

it is readily apparent that some grasses not mentioned here might —
be traced out in the key and be given wrong names. If a specimen
answers all the requirements of the key as a certain grass but does
| not correspond with the detailed description, it is evidently not in-
| cluded in this bulletin.
While the characters which have been used are the ones that appear
to be the most reliable, it is not uncommon to find individual speci-
mens of every species which differ from the majority. For instance,
tall oat-grass often has a few hairs on the sheaths. Timothy and a
number of other grasses sometimes have pink or violet colored sheaths
below ground when grown under certain conditions. It is very im-
_ portant to study several specimens of a species, if possible, before
| attempting to identify it.

No claim is made that this key is infallible. It has been of much
assistance to the writer in identifying the common hay and pasture
grasses, and it is hoped that 1t may serve the same purpose for others.

6 BULLETIN 461, U. S. DEPARTMENT OF AGRICULTURE,

The small grains, while true grasses, have been placed in a separate
group (p. 26), as there is more danger of confusing them with each
other than with the other grasses. The grasses studied are all
common to the eastern part of the United States, and no attempt has
been made to include the distinctively western species.

ANALYTICAL KEY TO GRASS SEEDLINGS.
GROUP I.—Leaves folded in the bud; shoot apparently flattened.

A. Auricles narrow and clawlike, clasping the stems more or less.
1. Perennial rye-grass (Lolium perenne).
AA. Auricles wanting, or at least not narrow and clawlike.
B. Collar hairy.
C. Stolons present, creeping.
2. Carpet grass (Axronopus compressus).
CC. Stolons absent.
D. Leaves less than one-fourth inch wide.
3. Poverty grass (Danthonia spicata).
DD. Leaves one-fourth inch wide.

E. Collar divided by the midnerve.

4. Broom sedge (Andropogon virginicus).

EE. Collar not divided by the midnerve.

5. Yard-grass (HLleusine indica).
BB. Collar not hairy.

C. Sheaths below ground bright yellow.

6. Crested dog’s-tail grass (Cynosurus cris-
tatus).
CC. Sheaths below ground not yellow.
D. Blades narrow and bristlelike, but with prominent veins on
upper surface.
BK. poe Ges Ww ee plant growing in a dense tuft.
7. Sheep’s fescue (Festuca ovina).
EE. Rootstocks ae plant creeping, forming an even turf.
8. Red fescue (Festuca rubra).
DD. Blades flat; nerves not prominent.
E. Blades broad without white lines along midnerve by trans-
mitted light; tip of blade taper pointed.
9. Orchard grass (Dactylis glomerata).

EE. Blades narrow, with a white line on each side of the
midnerve, the leaf being held up to the light and
examined with a lens; tip of blade abrupt, boat
shaped.

F. Rootstocks usually wanting.
10. Annual bluegrass (Poa annua).
FF. Rootstocks present. .
G. Herbage pale bluish green.
11. Canada bluegrass (Poa compressa).
GG. Herbage dark green.
H. Ligule short, truncate; stems smooth.
12. Kentucky bluegrass (Poa pratensis).
HH. Ligule long, acute; sheaths rough.
13. Rough-stalked meadow grass (Poa trivi- ._
alis).

IDENTIFICATION OF GRASSES. va

GROUP II.—Leaves rolled in the bud: shoot apparently cylindrical.

_ A. Auricles narrow and clawlike.
B. Sheaths reddish below ground; blades shining beneath.
C. Leaf margins smooth.
14. Italian rye-grass (Lolium multifiorum).
CC. Leaf margins rough.
15. Meadow fescue (Festuca elatior).
BB. Sheaths not reddish.
C. Rootstocks present.
16. Quack-grass (Agropyron repens).
CC. Rootstocks wanting.
' D. Hairs on sheaths pointing downward.
17. Virginia wild rye (Zlymus virginicus).
DD. Hairs on sheaths pointing upward.
18. Slender wild rye (Hlymus striatus).
AA. Auricles wanting, or at least not clawlike.
B. Sheaths not laterally compressed.
C. Collar or sheath hairy.
D. Sheaths not hairy. ;
19. Sweet vernal grass (Anthoranthum odo-
ratum).
DD. Sheaths hairy.
hi. Collar not hairy.
20. Soft chess (Bromus hordeaceus).
(NorE.—Tall oat-grass sometimes has hairy
sheaths ; it would then be placed here.)
EE. Collar hairy.
I’, Rootstocks present.
21. Switch-grass (Panicum virgatum).
FF. Rootstocks not present.
22. Downy brome-grass (Bromus tectorun).
Cc. Collar and sheaths not hairy.
D. Rootstocks or stolons present.
EK. Sheaths dark violet below ground.
23. Meadow foxtail (Alopecurus pratensis).
EE. Sheaths pale below ground.
IF’. Rootstocks more than one-eighth inch in diameter.
24. Reed canary grass (Phalaris arundinacea).
FF. Rootstocks less than one-eighth inch in diameter.
G. Leaves one-fourth inch wide.
25. Redtop (Agrostis alba).
GG. Leaves one-eighth inch wide.
26. Creeping bent (Agrostis stolonifera).
DD. Rootstocks and stolons not present.
EK. Sheaths white, with pink nerves.
27. Chess (Bromus secalinus).
EE. Sheaths without pink nerves.
EF. Margins of blades rough, retrorsely so near base.
28. Timothy (Phleum pratense).
FF. Margins of blades smooth.
G. Stems without buibs below ground.
29. Tall oat-grass (Arrhenatherum elatius).
GG. Stems with bulbs below ground. ~
30. Bulbous oat-grass (Arrhenatherum ela-
- tius bulbosum). ,

BULLETIN 461, U. S. DEPARTMENT OF AGRICULTURE,

BB. Sheaths laterally compressed.
C. Collar and sheath not hairy.
D. Rootstocks or stolons present.
E. Creeping stems (rootstocks) more than one-eighth inch in
diameter.
31. Johnson grass (Andropogon halepensis).
EE. Creeping stems (stolons) less than one-eighth inch in
diameter.
382. Nimble Will (Muhlenbergia schreberi).
DD. Rootstocks and stolons not present.
E. Ligule wanting.
33. Barnyard grass (Hehinochloa crus-galli).
EE. Ligule present.
~F. Ligule membranous.
34, Sudan grass (Andropogon sorghum
sudanensis ).
FF. Ligule a fringe of hairs.
G. Blades hairy above.
35. Yellow foxtail (Chaetochloa lutescens).
GG. Blades not hairy.
386. Spreading witch-grass (Panicum di-
chotomifiorum).
CC. Collar or sheath hairy (either or both).
D. Ligule membranous.
E. Sheaths white, with pink nerves.
F. Ligule entire, hairy on the back.
37. Rescue grass (Bromus unioloides).
FF. Ligule toothed on margin, not hairy on the back.
38. Velvet grass (Holcus lanatus).
EE. Sheaths pale, without pink nerves.
F. Stolons present.
G. Sheaths hairy.
39. Crab-grass (Syntherisma sanguinalis).
GG. Sheaths not hairy.
40. Small crab-grass (Syntherisma ischae-
mum).
FF. Stolons not present.
G. Habit of growth low and decumbent at the base.
41. Field paspalum (Paspalum laeve).
GG. Habit of growth upright.
42. Smooth paspalum (Paspalum dilatatum).
DD. Ligule a fringe of hairs. .
E. Rootstocks present.
438. Bermuda grass (Capriola dactylon).
EE. Rootstocks not present.
F. Sheaths hairy.
G. Collar hairy on the back.
44, False redtop (Tridens flavus).
GG. Collar not hairy on the back.
45. Green foxtail (Chaetochloa viridis).

IDENTIFICATION OF GRASSES. 9

FF. Sheaths not hairy.
G. Collar hairy on the back.
46. Flat-stemmed panic (Panicum anceps).
GG. Collar not hairy on the back.
H. Leaves one-sixteenth inch wide.
47. Slender meadow grass (Hragrostis pilosa).
HH. Leaves one-eighth inch wide.
48. Stink-grass (Hragrostis cilianensis).

DETAILED DESCRIPTIONS OF FORTY-EIGHT SEEDLING GRASSES.

1, Perennial rye-grass (Lolium perenne; fig. 5).

A perennial, glabrous, dark-green, tufted grass; leaves folded in the
bud; collar narrow, glabrous; auricles small, slender, clawlike; ligule
membranous, short, obtuse, toothed near the tip; sheaths reddish below
ground, smooth; blades’ flat, prominently
nerved above, glossy and smooth beneath,
long-linear, about one-eighth inch or more
wide, sharp pointed.

This grass makes considerable winter growth in
the Southern States and starts growth early in
the spring. It closely resembles Italian rye-grass
and meadow fescue when young, from which it is
readily distinguished by its folded leaf bud.

Fic. 5. — Perennial rye-grass Fic. 6.—St. Augustine grass (Stenotaphrum
(Lolium perenne) .1 americanum).

2. Carpet grass (Ax©onopus compressus ).

A perennial grass with creeping stolons, forming a dense turf; leaves
folded in the bud; collar narrow, indistinct, with a few hairs at margins;
auricles none; ligule a fringe of short hairs; sheaths glabrous, diverging
from stems; blades flat, usually short, linear, about one-eighth to one-

1 Hach figure shows a young plant and a detailed drawing of the leaf at the collar
illustrating the ligule and other appendages.

61167°—Bull. 461—17——2

10 BULLETIN 461, U. S. DEPARTMENT OF AGRICULTURE.

fourth inch wide, round pointed ; stolons compressed, about one-eighth inch
in diameter.* .

This grass is seldom found north of Tennessee or North Carolina, but it is common on
the sandv soils of the Gulf States. ;

3. Poverty grass (Danthonia spicata; fig. 7).

A tufted perennial; leaves folded in the bud; collar narrow, continu-
ous, hairy; auricles none; ligule a fringe of short hairs; blades often
curled, glabrous, rough on the under surface and margins, about one-
eighth inch wide, sharp pointed.

This grass is often found on poor sandy soils. The leaves, frequently curled, form a
small rounded tuft.

Fic. 7.Poverty grass (Danthonia spicata). 16. 8.—Broom sedge (Andropogon
virginicus).

4, Broom sedge (Andropogon virginicus; fig. 8).

A coarse, tufted perennial; leaves folded in the bud; collar small,
hairy, in two parts, separated in the middle by a broad gap; auricles none;
ligule membranous, hairy on the back and fringed with long hairs; sheaths
much compressed, hairy along the margins, merging indistinctly into the
blade; blades compressed near base, hairy along margins, about one-fourth
inch wide, sharp pointed.

The remains of the previous year’s growth persist as tough, woody, buff-colored tufts.

This grass is readily recognized by its peculiar collar, folded leaf bud, and strongly com- -
pressed sheaths and blades.

1 St. Augustine grass (Stenotaphruin americanum) would also trace to this place. It
very closely resembles carpet grass when young, but differs from it in the fact that the
collar is very much constricted (fig. 6).

IDENTIFICATION OF GRASSES. li
“SS
5. Yard-grass (Hleusine indica; fig. 9).

A tufted annual, decumbent at base; leaves folded in the bud; collar
broad, continuous, hairy; auricles none; ligule membranous, medium long,
coarsely toothed; sheaths white near the ground, green above. strongly
compressed, sparsely hairy along the margins; blades V-shaped in cross
section, about one-fourth inch wide, sparsely hairy above, tough in texture,
linear, obtuse pointed.

This is a common summer grass, making conspicuous tufts in lawns.

6. Crested dog’s-tail grass (Cynosurus cristatus; fig. 10).

A slender, erect, tufted perennial; leaves folded in the bud; collar broad,
continuous, glabrous; auricles none; ligule membranous, medium long,
truncate, toothed, continuous with the margins of the sheath; sheaths not
compressed, glabrous, bright yellow below ground; blades glossy below,
prominently nerved above, flat one-fourth inch wide, sharp pointed.

Tie. 9.—Yard-grass (Hleusine indica). Fic. 10.—Crested dog’s- Fic. 11.—Sheep’s
tail (Cynosurus cris- fescue (Festuca
tatus). ovina).

7. Sheep’s fescue (Festuca ovina; fig. 11).

A densely tufted perennial ; leaves folded in the bud; collar narrow, indis-
tinct, glabrous; auricles short, obtuse; ligule membranous, very short;
sheaths finely pubescent when viewed under a lens, not compressed, the
old ones remaining as dark-brown fibers; blades long, linear, thick, bristle.
like, about one-sixteenth inch wide, pale bluish green.

8. Red fescue (Festuca rubra; fig. 12).

A fine glabrous perennial grass with creeping rootstocks; leaves folded in
the bud; collar narrow, indistinct, glabrous; auricles none; ligule mem-
branous, short, entire, acute; sheaths minutely roughened, wider than
blades, not compressed, the old ones remaining as brownish red fibers ;
blades long, linear, thick, bristlelike, one-sixteenth inch or less wide, dark
green ; rootstocks fine, branching, producing tufts of shoots.2

1In some forms of velvet bent (Agrostis canina) it is difficult to determine whether
the leaf is folded or rolled in the bud. It may be distinguished from red fescue by its
soft, flat blades, which are prominently nerved. The old leaf sheaths of velvet bent are
grayish white in color instead of brown, as in red fescue.

~

12 BULLETIN 461, U. S. DEPARTMENT OF AGRICULTURE.

= J

This grass is distinguished from sheep’s fescue by its finer leaves, more acute ligule,
and habit of growth. Red fescue produces a fine even turf.

Fig. 12.—Red fescue (Fes- Fic. 13.—Orchard grass (Dactyiis glomerata).
tuca rubra).

9. Orchard grass (Dactylis glomerata; fig. 13).

A tufted, glabrous perennial; leaves foided in the bud; collar broad,
prominent, yellow; auricles wanting; ligule thin, membranous, very long,
often lacerate; sheaths white below, green above, strongly compressed, the

Fic. 14.—Annual bluegrass (Poa annua). Fig. 15.—Canada bluegrass (Poa compressa).

edges united below into a closed tube; blades long, soft, V-shaped in cross |
section, usually one-fourth inch or more wide, sharp pointed, pale green in |
color. |
This is a common meadow grass and is often found in pastures. It starts growth early |
in the spring.

IDENTIFICATION OF GRASSES. 13

10. Annual bluegrass (Poa annua; fig. 14).

A low-growing, glabrous, tufted annual; leaves folded in the bud; collar
glabrous; auricles none; ligule medium long, acute, entire; sheaths com-
pressed, glabrous; blades flat, short, linear, pale yellowish green, one-eighth
inch wide.

This grass often heads out when but 1 inch high. Rootstocks are rare; when present,

very short. In the South it makes considerable winter growth. Two white lines along
the midnerve may be noticed by holding a blade up to the light and examining with a lens.

11. Canada bluegrass (Poa compressa; fig. 15).

A glabrous, bluish green perennial with creeping rootstocks forming a
loose turf; leaves folded in the bud; collar light green; auricles none; ligule
membranous, entire, acute, medium long; sheaths strongly compressed, often
tinged with red; blades flat, long, linear, the apex like the bow of a boat,
bluish green but with double light lines along the midnerve when viewed by
transmitted light; rootstocks about one-sixteenth inch in diameter, each
branch usually terminating in a single shoot.

This grass has more of a bluish color and grows in looser turf than Kentucky bluegrass,
with which it is most likely to be confused.

Fic. 16.—Kentucky bluegrass (Poa Fic. 17.—Rough-stalked meadow grass
pratensis). (Poa trivialis).

12. Kentucky bluegrass (Poa pratensis; fig. 16).

A dark-green perennial, creeping by rootstocks and forming a dense turf;
leaves folded in the bud; collar narrow, glabrous; auricles none, ligule
membranous, very short, truncate, entire; sheaths green, smooth, com-
pressed ; blade long, linear, less than one-eighth inch wide, the tip abrupt
pointed like the bow ef a boat, dark green, but with two light lines along
the midnerve when viewed by transmitted light ; rootstocks slender, branch-
ing, producing tufts with several shoots.

13. Rough-stalked meadow grass (Poa trividlis; fig. 17).

A dark-green, glabrous perennial, creeping by stolons; leaves folded in
the bud; collar wide, glabrous; auricles none; ligule long, membranous,
toothed at apex; sheaths compressed, closed, rough to the touch; blades

14 BULLETIN 461, U. S. DEPARTMENT OF AGRICULTURE.
one-eighth inch wide, tapering to the tip; creeping stems always above
ground, giving off clusters of shoots.

This grass is distinguished from Kentucky bluegrass by being coarser and rough, by

the ligule, and by the above-ground stolons, the creeping stems of Kentucky bluegrass
being always below ground.

14, Italian rye-grass (Lolium multifiorum ;
fig. 18).

A tufted, glabrous annual, or some-
times perennial; leaves rolled in the
bud; collar prominent: auricles nar-
row and clawlike; ligule membranous,
short, thin, obtuse; sheaths not com-
pressed, strongly nerved, violet pink
below ground; blades three-sixteenths
inch wide, taper pointed, smooth on
the margins, prominently nerved on
the upper surface, glossy beneath;
nerves small, separated by light-green
lines when viewed by transmitted
light.

Fic. 18.—Italian rye-grass (Lolium multi-

This grass is very similar to perennial rye-
jilorum).

grass and meadow fescue. It is distin-
guished from meadow fescue by the smooth leaf margins and the nervation of the blades
when held up to the light and viewed with a lens. It is distinguished from perennial rye-
grass by its leaf bud, Italian rye-grass being convolute and perennial rye-grass folded.

yy
Y
YY
H] =
\\ iy ‘
\\ Y), H
- \\ / i
\ j ij
\ | /
2 i \f
|
- _—
=A 5 => Dey:
it f oo =
(
y r
Fic. 19.—Meadow fescue (Festuca elatior). Fic. 20.—Quack-grass (Agropyron repens),

15. Meadow fesoue (Festuca elatior; fig. 19).

A tufted, glabrous, dark-green perennial; leaves rolled in the bud; collar
broad, continuous; auricles none; ligule membranous, short, truncate;

IDENTIFICATION OF GRASSES. 15

sheaths not compressed, reddish pink below ground; blades flat, sharp
pointed, rough on the margins, glossy beneath, nerved above, three-
sixteenths inch wide; nerves separated into pairs by white lines when
viewed by transmitted light.

This grass closely resembles both Italian rye-grass and perennial rye-grass. It may be
distinguished from Italian rye-grass by its rough-margined blades (test with the tongue)
and also by the nerves in the blades. Perennial rye-grass is distinguished by having its
leaves folded in the bud.

16. Quack-grass (Agropyron repens; fig. 20).

A pale-green perennial, creeping by its long rootstocks; leaves rolled in
the bud; collar broad, continuous, hairy; auricles slender, clawlike; ligule
membranous, short, entire; sheaths hairy, not compressed ; blades flat, finely
hairy at the base, sharp pointed, one-fourth inch wide; nerves broad, not
prominent ; rootstocks strong, elongate, one-eighth inch or more in diameter.

This is a common, very aggressive grass. The hairs, while quite noticeable in the
spring, are often invisible in the fall unless a lens is used.

Fic. 21.—Virginia wild rye (Hlymus Fig. 22.—Slender wild rye (Elymus
virginicus). Striatus).

17. Virginia wild rye (Hlymus virginicus; fig. 21).

A loosely tufted perennial ; leaves rolled in the bud; collar broad, glabrous,
continuous ; auricles Short, clawlike ; liguie membranous, very short, entire ;
sheaths not compressed, glabrous, fine veined, retrorsely hairy; blades flat,
glabrous, dull above, glossy beneath, rough on the margins, one-fourth to
one-half inch broad, sharp pointed; nerves small, indistinct.

This grass resembles the small grains in habit of growth.

18. Slender wild rye (Elymus striatus; fig. 22).
A loosely tufted perennial; leaves rolled in. the bud; collar narrow,
glabrous, continuous; auricles long, slender, clawlike, overlapping; ligule
short, membranous, entire; sheaths not compressed, hairy, the hairs point-

16 BULLETIN 461, U. S. DEPARTMENT OF AGRICULTURE.

ing upwards; blades flat, glossy beneath, dull and densely pubescent above
and velvety to the touch, rough on the margins, one-fourth inch wide, sharp
pointed.

Fig. 23.—Sweet vernal grass (Anthoz- Fic. 24.—Soft chess (Bromus hordeaceus).
anthum odoratum).

19. Sweet vernal grass (Anthoxanthum odoratum ; fig. 23).

A low-growing tufted perennial; leaves rolled in the bud; collar broad,

hairy; auricles none; ligule long, obtuse, membranous; sheaths glabrous,
not compressed; blades fiat,
the margins rough and some-
times sparsely hairy near the
base, one-fourth inch wide,
sharp pointed.

This grass is easily recognized by its

sweet odor, which becomes more pro-
nounced in drying.

Fig. 25.—Switch-grass (Panicum virgatum). Fig. 26.—Downy brome-grass (Bro-

mus tectorum).
20. Soft chess (Bromus hordeaceus; fig. 24).

A slender, tufted annual; leaves rolled in the bud; collar broad, with
Wavy margins, glabrous; auricles none; ligule membranous, medium long,

IDENTIFICATION OF GRASSES. 17

truncate, toothed, hairy on the back; sheaths with reddish pink veins, not
compressed, densely hairy; blades flat, hairy, one-fourth inch wide, sharp
pointed; nerves distinct, separated by dark-brown lines.

21. Switch-grass (Panicum virgatum ; fig. 25).

A coarse perennial, creeping by rootstocks; leaves rolled in the bud;
collar broad, continuous, hairy ; auricles none; ligule a fringe of short hairs,
in front of a tuft of fine, soft hairs at the base of the blade; sheaths not
compressed, hairy along the margins near the top; blades flat, narrowed at
base, one-fourth to one-half inch wide, taper pointed ; rootstocks strong, one-
eighth inch or more in diameter.

\
\

Fic. 27.—Meadow foxtail (Alope- Fic. 28.—Reed canary grass (Phalaris arundi-
curus pratensis). nacea).

22. Downy brome-grass (Bromus tectorum; fig. 26).

A slender, tufted annual; leaves rolled in the bud; collar narrow, con-
tinuous, hairy; auricles none; ligule medium long, acute, hairy on the
margin near the apex; sheaths not compressed, hairy, veiny, the veins
pinkish below ground; blades flat, weak, hairy, one-fourth inch wide, sharp
pointed.

23. Meadow foxtail (Alopecurus pratensis; fig. 27).

A glabrous perennial with short rootstocks; leaves rolled in the bud;
collar broad, glabrous; auricles none; ligule membranous, long, obtuse;
sheaths smooth, not compressed, dark violet to maroon below ground;
blades flat, one-fourth inch wide, rough on the upper surface and along the
margins; rootstocks strong, branched, short, partly above ground, each ter-
minating in a single shoot.

18 BULLETIN 461, U. S. DEPARTMENT OF AGRICULTURE.

24. Reed canary grass (Phalaris arundinacea; fig. 28).

A coarse, glabrous perennial with stout rootstocks; leaves rolled in the
bud; collar broad, spiral, with wavy margins; auricles none; ligule very
long, obtusc, membranous, often torn, hairy on the back, wider than the
sheaths; sheaths not compressed, hya-
line on the margins; blades flat, rough
on the margins, one-half inch or more
wide, sharp pointed; rootstocks more
than one-eighth inch in diameter.*

25. Redtop (Agrostis alba; fig. 29).

A dark-green, glabrous perennial,
creeping by rootstocks ; leaves rolled in
the bud ; collar narrow, divided into two
parts by a space, glabrous; auricles
none; ligule membranous, thin, very
long, acute, finely toothed; sheaths
smooth, not compressed; blades flat,
distinctly nerved above, rough mar-
gined, one-fourth inch or more wide,
sharp pointed; rootstocks about one-
sixteenth inch in diameter.

Redtop. when young, resembles timothy, from
which it is distinguished by its ligule, root-
Fig. 29.—Redtop (Agrostis alba). stocks, and coarsely nerved leaves.
26. Creeping bent (Agrostis stolonifera; fig. 30, A).
A fine-leafed glabrous perennial, creeping by rootstocks; leaves rolled in
the bud; collar narrow; auricles none; ligule short, rather obtuse; sheaths

Fic. 30.—A, Creeping bent (Agrostis stolonifera) ; B, velvet bent (Agrostis canina).

smooth, not compressed; blades flat, distinctly nerved above, one-eighth
inch or less wide, taper pointed ; rootstocks very fine, branching, producing
numerous tufts.

+A variety of this grass called ribbon grass and grown for ornamental purposes is
readily recognized by its green leaves striped with white.

IDENTIFICATION OF GRASSES. 19

This grass produces a fine, dense turf. Velvet bent (Agrostis canina; fig. 30, B) is

similar to creeping bent, but grows in a still finer turf and is distinguished by a long

acute ligule and by scabrous blades when viewed with a lens.

Fig. 31.—Chess (Bromus secalinus). Fic. 32.—Timothy (Phleum pratense).

27. Chess (Bromus secalinus; fig. 31).

A tufted, pale-green annual; leaves rolled in the bud; collar broad,
glabrous; auricles none; ligule short, membranous, toothed near the tip;

Fig. 34.—Bulbous oat-grass-
Fig. 33.—Tall oat-grass (Arrhenatherum _ elatius

(Arrhenatherum elatius). bulbosum).

Sheaths not compressed, glabrous, rarely hairy, pink veined; blades flat,
glabrous, or sometimes sparsely hairy above, one-fourth inch wide.
This grass is often found in fields of winter grain.

20 BULLETIN 461, U. S. DEPARTMENT OF AGRICULTURE,

28. Timothy (Phileum pratense; fig. 32).

A stout, glabrous, tufted perennial ; leaves rolled in the bud; collar broad,
continuous; auricles none; ligule membranous, short, obtuse, the apex
usually with several large teeth; sheaths not compressed ; blades flat, indis-
tinctly nerved, rough on the margins, one-fourth inch wide, sharp pointed.

The thickened base, or “ corm,” of the old stem usually may be found attached above
the young plant below ground.

29. Tall oat-grass (Arrhenatherum elatius; fig. 33).

A loosely tufted perennial; leaves rolled in the bud; collar broad, divided
into two parts by a space, glabrous; auricles none; ligule membranous,
medium long, obtuse, finely toothed at apex, hairy on the back, sheaths not
compressed, usually glabrous, sometimes sparsely hairy, prominently nerved ;
blades flat, linear, one-half inch or more wide, sharp pointed; nerves in
pairs, not prominent, separated by white lines as seen by transmitted light.

30. Bulbous oat-grass (Arrhenatherum ela-
tius bulbosum ; fig. 34).

A loosely tufted perennial; leaves
rolled in the bud; collar broad, glabrous,
divided into two parts by a gap; auricles
none; ligule membranous, medium long,
obtuse, finely toothed at apex, hairy on
the back; sheaths not compressed, usually

Fic. 35.—Johnson grass (Andro- Fic. 36.—Nimble Will (Muhlenbergia
pogon halepensis). schreberi).
glabrous, sometimes sparsely hairy, prominently nerved; blades flat, linear,
one-fourth inch or more wide, sharp pointed; nerves in pairs, separated by
white lines when viewed by transmitted light.

There is a chain of from two to five bulbous growths at the base of the stems below
ground which distinguishes this grass from tall oat-grass. Bulbous oat-grass has been
recently introduced into this country and is occasionally found in eastern Virginia and
North Carolina.

31. Johnson grass (Andropogon halepensis; fig. 35).

A nearly glabrous perennial, creeping by rootstocks; leaves rolled in the
bud; collar broad; auricles none; ligule membranous, long, obtuse, lacerate
ciliate at top; sheaths compressed, glabrous, usually pale, the outer ones
sometimes reddish brown; blades flat, narrowed at base, and hairy at the
very base, one-half inch or more wide, sharp pointed ; midnerve white, very
thick ; rootstocks one-fourth inch or morc in diameter.

IDENTIFICATION OF GRASSES. aA

32. Nimble Will (Muhlenbergia schreberi; fig. 36).

A pale-green, glabrous perennial, creeping by stolons; leaves rolled in the
bud; collar narrow, glabrous; auricles none; ligule membranous, short,
lacerate; Sheaths compressed, loose; blades short when young, soft and flat;
stolons very slender, hard, wiry, much branched, the joints one-half to 1

inch long.

Often the fine, very much branched stolons of this grass lie off the ground and take
root only when the joints come in contact with the soil.

33. Barnyard grass (Hchinochloa crus-galli; fig. 37).

A coarse, nearly glabrous, tufted annual; leaves rolled in the bud; collar
broad, continuous, glabrous; auricles none; ligule wanting; sheaths com-
pressed, the outer ones with pink nerves, the inner ones pale; blades flat,
narrowed at base, the midnerve thick, sometimes sparsely hairy along the
margins near the base, one-half inch or more wide, sharp pointed.

Fic. 37.—Barnyard grass (Echinochloa crus- Fig. 38.—Sudan grass (Andropogon sor-
galli). ghum sudanensis).

34. Sudan grass (Andropogon sorghum sudanensis; fig. 38).

A coarse, nearly glabrous annual; leaves rolled in the bud; collar broad,
continuous, glabrous; auricles none; ligule membranous, long, lacerate,
wider than the sheaths; sheaths slightly compressed, hyaline margined ;
blades flat, narrowed at base, pale green above, one-half inch or more wide,
sharp pointed; midnerve thick, pale green.

This grass is similar to Johnson grass, but it does not have rootstocks. The midnerve
is also distinctive.

35. Yellow foxtail (Chaetochloa lutescens; fig. 39).

A coarse, tufted annual; leaves rolled in the bud; collar narrow, yellow,
continuous, glabrous; auricles none; ligule a fringe of short hairs; sheaths
compressed, glabrous ; blades flat near the base, hairy on the upper surface,
one-fourth inch or more wide, sharp pointed.

Pa BULLETIN 461, U. S. DEPARTMENT OF AGRICULTURE,

36. Spreading witch-grass (Panicum dichotomifiorum; fig. 40).

A coarse, tufted, glabrous annual; leaves rolled in the bud; collar broad,
continuous, glabrous; auricles none; ligule a fringe of hairs; sheaths slightly
compressed, glabrous; blades flat, glossy beneath, dull above, one-half ——
wide, sharp pointed; midnerve light green, slightly rough.

37. Rescue grass (Bromus unioloides; fig. 41).

A coarse, tufted grass, annual or sometimes perennial ; leaves rolled in the
bud; collar broad, continuous, hairy; auricles none; ligule long, membra-
nous, entire, hairy on the back; sheaths strongly compressed, hairy, the
older ones with pink nerves; blades flat, sparsely hairy, one-half inch wide.

This grass makes considerable winter growth in the Southern States.

38. Velvet grass (Holeus lanatus; fig. 42).
A pale, tufted, hairy perennial; leaves
rolled in the bud; collar continuous,
hairy ; auricles none; ligule short, mem-
branous, coarsely toothed at apex, hairy

on the back; sheaths compressed, pink |
nerved, densely hairy; blades flat, soft, |
hairy, one-half inch wide, sharp pointed. —

Fic. 39.—Yellow foxtail (Chaetochloa Fic. 40.—Spreading witch-grass
luteseens). (Panicum dichotomifiorum.)

39. Crab-grass (Syntherisma sanguinalis; fig. 43).

A pale-green annual, creeping by stolons; leaves rolled in the bud; collar
broad, prominent, sparsely hairy; auricles none; ligule membranous, long,
acute, toothed; sheaths compressed, hairy; blades flat, sparsely hairy, wavy
margined, one-fourth inch wide, sharp pointed ; stolons about one-sixteenth
inch in diameter, much branched.

40. Small crab-grass (Syntherisma ischaemum; fig. 44).
A low-growing annual, creeping by stolons; leaves rolled in the bud; collar ;
broad, sparsely hairy; auricles none; ligule membranous, long, entire; |
sheaths compressed, glabrous; blades flat, sparsely hairy at base, otherwise
glabrous, one-fourth inch wide, sharp pointed; stolons about one-sixteenth
inch in diameter, branched.

IDENTIFICATION OF GRASSES. 23

41. Field paspalum (Paspalum laeve; fig. 45).

A coarse, tufted perennial; leaves rolled in the bud (fig. 4, C); collar
hairy, broad, continuous; auricles none; ligule membranous, thin, acute,

Fie. 41.— Rescue grass (Bromus Fig. 42.— Velvet grass (Holcus lanatus).
unioloides).

long; sheaths strongly compressed, sparsely hairy on the margins and mid-
nerve; blades flat, hairy above, near the base, and along the margins, one-
fourth inch wide, sharp pointed, tinged with reddish brown near tips.

P1e, 43.—Crab-grass (Syntherisma Fig. 44.—Small crab-grass (Syntherisma
sanguinalis). ischaemum).

This grass very closely resembles smooth paspalum, false redtop, and flat-stemmed panic
when young. The blades are usually creased lengthwise from the manner in which they
are rolled in the bud. It starts growth in late spring.

j

24 BULLETIN 461, U. S. DEPARTMENT OF AGRICULTURE,

42. Smooth paspalum (Paspalum dilatatum; fig. 46).

A coarse, tufted perennial; leaves rolled in the bud; collar medium broad,
continuous, hairy; auricles none; ligule membranous, thin, acute, long;
sheaths strongly compressed, densely hairy below, sparsely so above; blades
sparsely hairy at base, one-fourth inch wide, sharp pointed, thin, narrowed
at base.

Smooth paspalum is a taller growing grass than field paspalum, which it closely resem-
bles. The densely hairy sheaths and usually darker green color are characteristic. It is

often grown in the Southern States for hay. The membranous ligule distinguishes this
grass from false redtop and flat-stemmed panic.

43. Bermuda grass (Capriola dactylon; fig. 47).

A low-growing perennial, creeping by rootstocks or stolons, or both; leaves
rolled in the bud; collar narrow, with a ring of stiff hairs; auricles none;
ligule a fringe of short hairs; sheaths strongly compressed, sparsely hairy ;
blades soft, rough margined, one-eighth inch wide, sharp pointed; root-
stocks one-eighth inch in diameter, mostly below ground, but becoming
stolons on hard soil.

Fig. 45.—Field paspalum (Paspalum Fic. 46.—Smooth paspalum (Paspalum
laeve). dilatatum).

44. False redtop (Tridens flavus; fig. 48).

A coarse, tufted perennial; leaves rolled in the bud (fig. 4, @): collar
hairy on the back; auricles none; ligule a fringe of short hairs; sheaths
strongly compressed, tough, firm, smooth, glossy, slightly hairy on the upper
margins; blades narrowed at base, taper pointed, minutely hairy above,
smooth and glossy beneath, one-half inch wide, sharp pointed.

This grass closely resembles the field and the smooth paspalums, from which it is
distinguished by its ligule, and flat-stemmed panic, from which it differs in not having

rootstocks. The leaves are creased lengthwise from the manner in which they are rolled
in the bud.

—

IDENTIFICATION OF GRASSES. 25

45. Green foxtail (Chaetochloa viridis; fig. 49).

A coarse, tufted annual; leaves rolled in the bud; collar narrow, hairy;
auricles none; ligule a fringe of hairs, longest near the margins; sheaths
slightly compressed above, hairy along the margins; blades soft, flat, nar-
rowed at base, one-fourth to one-half inch wide, sharp pointed.

46. Flat-stemmed panic (Panicum anceps; fig. 50).

A coarse perennial with short rootstocks; leaves rolled in the bud
(fig. 4, C) ; collar hairy on back and margins; auricles none; iigule a fringe

Fic. 47.—-Bermuda grass (Capriola dactylon). Wig. 48.—False redtop (Tridens
flavus).

of short hairs; sheaths strongly compressed, glossy, usually glabrous; blades
sparsely hairy on upper surface near base, three-eighths to one-half inch
wide, sharp pointed.

This grass closely resembles the field and smooth paspalums, from which it is distin-

guished by its hairy ligule and rootstocks, and also false redtop, from which it differs in
the presence of rootstocks.

47. Slender meadow grass (Hragrostis pilosa; fig. 51).

A slender, tufted annual; leaves rolled in the bud; collar narrow, hairy;
auricles none; ligule a fringe of hairs; sheaths slightly compressed, gla-
brous; blades dull and sparsely hairy above, glossy below, less than. one-
eighth inch wide, sharp pointed.

It closely resembles stink-grass, but it is not so large.

26 BULLETIN 461, U. S. DEPARTMENT OF AGRICULTURE,

48. Stink-grass (Hragrostis cilianensis; fig. 52).

A slender, tufted, often decumbent annual; leaves rolled in the bud; collar }°

narrow, hairy; auricles none; ligule a fringe of hairs; sheaths glabrous,

Fig. 51.—Slender mead-
Fic. 49.—Green foxtail (Chae- Fig. 50.— Flat - stemmed ow grass (Hragrostis
tochloa viridis.) panic (Panicum anceps). pilosa).

slightly compressed; blades flat, dull, and sparsely hairy above, glossy
beneath, one-eighth inch wide.

Stink-grass is very similar to slender meadow grass
except that the plants of stink-grass are about twice as
large as those of slender meadow grass. In most botan-
ical works this grass is called Hragrostis major.

IDENTIFICATION OF SMALL-GRAIN
SEEDLINGS.

The seedlings of small grains are, under
all conditions, very difficult to identify.
Men who are constantly growing these
grains usually learn to distinguish the
different species. Even certain varieties
in a species are sometimes recognizable.
But there is great variation even in the
different varieties, and the varietal differ-
ences in each species make it difficult to find

Fig. 52.—Stink-grass (Hra. 2 Combination of characters that will always

Ghost coninciists)- hold true for the species.

All of the small grains so far as studied have their leaves rolled

in the bud. The most dependable characters are found in the collar,

4
”

5

&

IDENTIFICATION OF GRASSES. 97

the presence or absence of claws, the pubescence and the general
shape of the blades, especially at the tips. The lgules of all are
very similar, the principal differences being in shape and length.

ANALYTICAL KEY TO SMALL-GRAIN SEEDLINGS.

A. Collar without clawlike appendages.
49. Oats (Avena sativa).
AA. Collar with clawlike appendages which clasp the stem more or less.
B. Claws hairy.
C. Sheaths and blades finely pubescent, soft, and velvety.
50. Emmer (Triticum dicoccum).
CC. Sheaths and blades not pubescent.
D. Collar and claws large.
51. Spelt (Triticum spelta).
DD. Collar and claws slender.
52. Wheat (Triticum aestivum).

BB. Claws not hairy.
| C. Collar and claws large and prominent.
D. Nerves of blades not prominent, upper surface rough.
53. Barley (Hordeum sativum).
DD. Nerves of blades broad and prominent, smooth on upper sur-
face.
54. Polish wheat (Triticum polonicum).
CC. Collar and claws slender.
D. Blades and sheaths sparsely hairy.
55. Rye (Secale cereale).
DD. Blades and sheaths free from hairs.
56. Durum wheat (Triticum durum).

DETAILED DESCRIPTIONS OF EIGHT SMALL-GRAIN SEEDLINGS.

49. Oats (Avena sativa; fig. 53).

Collar broad, separated into two parts by midnerve, free from claws,
finely hairy; ligule membranous, long, acute, toothed; sheaths sparsely
hairy ; blades hairy along margins, flat, rough, one-half inch wide.

The blades are longer and more taperingly pointed than those of wheat. Some varieties

of spring oats are free from hairs on sheaths and blades. Spring oats have a more upright
habit of growth than the winter varieties.

50. Emmer (Triticum dicoccum; fig. 54).

Collar medium broad, with claws; collar and claws sparsely hairy ; ligule
thin, membranous, acute, toothed; sheaths finely pubescent, soft and vel-
vety, the hairs seen only with a lens, one-fourth inch wide, sharp pointed ;
blades prominently nerved.

51. Spelt (Triticum spelta; fig. 55).

Collar broad, similar to that of barley, with large, hairy claws; ligule
membranous, medium long, toothed, acute; sheaths free from hairs; blades
free from hairs near base except a few at margins, one-fourth inch or more
wide, sharp pointed on older, abrupt on younger plants; nerves small.

~

28 BULLETIN 461, U. S. DEPARTMENT OF AGRICULTURE.

52. Wheat (Triticum aestivum; fig. 56).

Collar broad, not spiral, continuous, with small, slender claws, hairy
along margins and claws; ligule long, truncate, toothed; sheaths not keeled,

free from hairs; blades long, free from hairs, smooth, flat, the older ones
abrupt pointed, one-half inch wide.

Fie. 53.—Oats (Avena sativa). Fic. 54.—Emmer (Triticum dicoccum).

58. Barley (Hordeum sativum; fig. 57).

Collar broad, prominent, yellow, sometimes red, one side higher than the
other, with large claws clasping the young shoot spirally; ligule membra-

Fig. 55.—Spelt (Triticum spelta). Fic. 56.—Wheat (Triticum sativum).

nous, medium long, acute, entire; sheaths sparsely yJairy; blades broad at
base, shorter than those of wheat, rough on upper surface, one-half inch

wide, sharp pointed ; nerves not prominent, covered with white specks when
viewed under a lens,

IDENTIFICATION OF GRASSES. 29

54. Polish wheat (Triticum polonicum ; -fig. 58).
Collar broad, spiral, with claws, hairy on margins and claws; ligule long,
acute, notched on top; sheaths not hairy; blades one-half inch wide, long,
sharp pointed; nerves broad and prominent on upper surface.

Fie. 57.—Barley (Hordeum sativum). Fig. 58.—Polish wheat (Triticum polonicum).

It is difficult to find characters which will distinguish this grain from barley, although
there is considerable difference in the appearance of the two when growing. The claws

Fig. 59.—Rye (Secale cereale). Fic. 60.—Durum wheat (Triticum durum).

of Polish wheat are more slender than those of barley and may have rudimentary hairs
when viewed with a lens, while barley has none. The collar of Polish wheat is not so
broad and prominent as that of barley.

30 BULLETIN 461, U. S. DEPARTMENT OF AGRICULTURE,

dd. Rye (Secale cereale; fig. 59).

Collar broad, not spiral, continuous, with fine, sharp claws barely over-
lapping; ligule short, truncate, lacerate; sheaths sometimes hairy; blades
toothed on margins, hairy at base on upper side, sparsely hairy elsewhere, ©
one-half inch wide, abrupt pointed.

The sheaths and blades are usually covered with a powdery bloom, which gives a pale |
bluish cast to this plant. —

56. Durum wheat (Triticum durum; fig. 60).

Collar broader than that of common wheat, but not so noticeable as that
of barley; claws small, free from hairs; ligule acute, thin, membranous,
toothed, medium long; sheaths free from hairs; blades prominently nerved,
soft, glabrous, one-half inch wide, abrupt pointed.

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