MORPHOLOGY OF THE FLORAL ORGANS “125 
awns, as in some species of Chloridez, is to be recognized 
by its position on the rachilla. In canary-grass (Phalaris 
canariensis L.) there are 2 minute bracts at the base of the 
fertile lemma. These are greatly reduced lemmas. The 
indurated lemma of Stipa and Aristida is peculiar in that 
it assumes a cylindrical form and extends downward into 
a hard, sharp-pointed callus (Figs. 35, 36). At maturity 
the fruits, by means of this sharp point and by the 
hygroscopic awns at the apex, are able to bury themselves 
in the soil. Certain genera of Andropogonee (Hetero- 
pogon, Chrysopogon) produce fruits similar in general 
appearance to those of Stipa, but in the former the fruit 
is developed from a spikelet instead of from a floret. 
In Heteropogon and other genera of Andropogonez with stout 
awns, the first glume is indurated, cylindrical and sharp-pointed at 
base as in the lemma in Stipa. Within this are the second glume, the 
sterile lemma and the fertile lemma, all thin and hyaline, the latter 
bearing the long stout awn. 
155. Sterile florets and sterile lemmas.—Sterile florets 
are those which differ from the perfect florets of the spike- 
let in which they are found in lacking pistils. They may 
also lack stamens, and consist of a lemma and palea, or 
the palea also may be lacking. The lemma of such a 
floret is called a sterile lemma. If a lower floret lacks 
stamens, then the lemma is the same as the third empty 
glume of some authors, when they refer to bracts above 
the first pair. In many genera of the series Poaoideze the 
upper florets are reduced to sterile florets. In Melica 
there may be 2 or 3 sterile lemmas successively convolute 
one within another. In most of the genera of Panicoidez 
there is a sterile floret below a terminal perfect one. The 
sterile floret of Panicum and its allies has been mentioned 
