32 



FIRST BOOK OF GRASSES 



while the sterile spikelets are many-flowered and 



awnless. 

 We shall next examine a grass having unisexual 



spikelets (see Lesson III, page 23), the two forms 

 borne on different plants (dioecious). 

 (In the group with relatively simple ' y 

 spikelets which we are now studying / 

 there are no monoecious grasses) jr 

 In Fig. 23 are shown the pistillate 

 and staminate spikelets of salt-grass 

 {Distichlis spicata). They differ but 

 little in appearance and are both 



Fig. 23. Pistillate 

 and staminate 

 spikelets of Dis- 

 tichlis spicata. 



borne in narrow 

 panicles. [9 sig- 

 nifies female, & 

 male. These signs 

 are commonly 

 used to indicate 

 pistillate and sta- 

 minate plants, 

 respectively.] 



In Fig. 24 are 

 seen the strikingly 

 diverse staminate 

 and pistillate spikelets of another dioecious species 



Fig. 24. Staminate and pistillate spikelets of 

 Scleropogon breiiifoliua. 



