124 A TEXT-BOOK OF GRASSES 
154. The lemmas are the bracts of the spikelet above 
the glumes. They ordinarily subtend flowers but some- 
times are empty. The lemmas vary from 1 to many (as 
many as 50 in Eragrostis) and except in Streptocheta are 
in 2 ranks upon the rachilla. As is usually the case with 
bracts, the lemma represents the leaf-base, the blade 
not being developed. 
Streptocheta is an anomalous Brazilian genus in which the 
lemmas are spirally arranged. 
In the more primitive forms of grasses, the lemmas 
are usually bract-like in appearance and in a general way 
resemble the glumes, being greenish, keeled and nerved. 
In more modified forms such as Andropogonee, the lemmas 
are often thin and delicate, being entirely inclosed by the 
enlarged and indurated glumes. On the other hand, the 
lemma may be hardened, as in most Panicez, where the 
lemma of the fertile floret is hard, usually smooth and 
nerveless. Modification is carried to a greater extent in 
the lemma than in any other organ of the grass plant. 
For this reason the form of the lemma is of great impor- 
tance in classification, its shape, texture and nerving being 
uniform within definite limits in any given genus. In 
those genera, such as Andropogon and its relatives, 
Hilaria, Anthephora and the like, in which the glumes are 
enlarged, indurated or otherwise specialized, the lemmas 
are found to be thin or small or otherwise to show but 
little modification. 
In grasses having unspecialized or but slightly modi- 
fied glumes, as in most of the genera, the lemmas are 
usually strongly characteristic. The lemma, whether 
bearing a fertile flower or empty, as in the lower lemma in 
most species of Paniceze, or modified into a cluster of 
