92 



FIRST BOOK OF GRASSES 



Buffalo-grass (Bulbilis dactyloides) is placed in the 

 same tribe as the grama-grasses (page 57), but it has 

 been left until the last, so that the student might have 

 greater experience to draw on. It is dioecious (p. 23), 

 and the staminate and pistillate inflorescences are 

 strikingly different. (Recall Fig. 24, p. 32). 



Examine Fig. 82, B, 

 showing a pistillate 

 spikelet with a small 

 narrow first glume and 

 a very large, broad, 3- 

 toothed second glume 

 entirely infolding the 

 body of the floret. The 

 floret, removed from 

 the glume, is shown 

 in Fig. 82, C. Its 3- 

 toothed lemma ap- 

 proaches in form the 

 lemma of some of the 

 grama-grasses . (Com- 

 pare with Fig. 50, B). 

 This pistillate spike- 

 let as presented is not 

 at all puzzling, the 

 large thick second glume with overlapping edges en- 

 tirely inclosing the floret being the only remarkable 

 feature. These spikelets, however, are borne in the 

 curious inflorescence shown in Fig. 82, A. These little 

 hard white heads are borne, mostly two together, on 



Fig. 82. A, pistillate inflorescence of 

 Bulbilis dactyloides; B, pistillate 

 spikelet cut from the rachis; C, pis- 

 tillate floret; D, diagram of half a 

 head, showing one of the two rows 

 of spikelets; E, staminate inflores- 

 cence; F, staminate spikelet. 



