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 
