44 Graminaceae 
the joint. Glumes subequal, with a terminal straight awn. Lemma smaller than the 
glumes, thinner, usually hyaline, entire or notched, with an awn in the notch or on the 
back; awn either twisted and bent at base or small and straight, or reduced to a minute 
point. Palet smaller than the lemma. Stamens 1—3. Stigmas plumose. Grain free. 
In wet places. (Gk. polys—much, pogon=beard.) 
A. Panicles dense, cylindric; glumes notched at apex, with awns 2—3 times their 
length; annual. W. E. P. monspeliensis Desf. (Annual Beard-grass) 
AA. Panicles lobed or interrupted; glumes obtuse or attenuate at apex, with awns 
equaling them; perennial. W. 
FP. littoralis Sm. (Seaside Beard-grass) 
SPOROBOLUS DROP-SEED 
Annual or perennial. Leaves flat or rolled up. Spikelets in an open-pyramidal 
to spike-like panicle. Rachilla very short, glabrous, scarcely jointed, not prolonged be- 
yond the flower. Glumes usually unequal, membranous,. awnless, slightly keeled or 
convex, 0—3-veined. Lemma 0—3-veined, as long as the glumes or longer, in ours 
awnless but sometimes very acuminate. Palet as long as its lemma or shorter, with 2 
prominent veins and often split between them. Stamens 2—3. Grain free, readily 
falling from the spikelet; ovary loosely enclosing the seed, often thin and evanescent. 
(Gk. spora=seed, ballein—to cast forth; referring to the deciduous grain.) 
A. Panicle contracted, spike-like. 
B. Annual. 
C. Upper leaf projecting beyond the panicle. E. (S. vaginaeflorus neglectus.) 
S. neglectus Nash (Poverty-grass) 
CC. Upper leaf not reaching the top of the panicle. W.E. (S. filiformis; S. 
gracillimus. ) S. simplex Scribn. (Mountain Drop-seed) 
BB. Perennial. 
D. Lemma 1.7mm. long. E. 
S. depauperatus Scribn. 
DD. Lemma 3—3.5 mm. long. 
E. Stem smooth; glumes acuminate, 2/3 as long as the lemma; ligule 0.5 mm. 
long; spikelets 4 mm. long. E. (S. cuspidatus.) 
S. brevifolius Scribn. (Short-leaved Drop-seed) 
EE. Stem minutely roughened by cross-walls; glumes acute, less than 1% as 
long as the lemma; ligule 2 mm. long; spikelets 3 mm. long. E. 
S. richardsonis Mer. 
AA. Panicle open, branches mostly spreading. 
F. Plant 6—9 dm. high; spikelets not purplish, 1.5—-3 mm. long; lower glume 
V/the length of the upper or less; lemma |-veined or veinless, 1.5—-2 mm. long. 

G. Sheaths naked or sparingly ciliate at the throat; panicles 2—-3 dm. long; . 
spikelets 1.5—-2 mm. long; glumes veinless, glabrous. E. 
S. airoides Torr. (Fine-top Drop-seed) 
GG. Sheaths with.a conspicuous tuft of hairs at the throat; panicles 1—2 dm. 
long; spikelets 2—2.5 mm. long; glumes |-veined, scabrous on the keel. C. E. 
S. cryptandrus Gray (Sand Drop-seed) 
FF. Plant 0.8—4 dm. high; spikelets somewhat purplish, I1—1.5 mm. long; 
glumes equal or nearly so; lemma 3-veined, 1|—1.5 mm. long. 
H. Annual; lemma | mm. long or less. E. 
S. confusus Vas. 
HH. Perennial; lemma |—1.5 mm. long. C. E. 
S. asperifolius Thurb. (Rough Drop-seed) 
