HOW TO KNOW THE GRASSES 



Tribe X. ZIZANIEAE. Aquatic grasses; spikelets 

 consisting of a single staminate or pistillate 

 floret; glumes lacking or reduced to ridges at 

 the tip of the pedicel. Fig. 19. Pages 147, 148. 



Figure 19 



Subfamily PANICOIDEAE. Spikelets with a single perfect floret 

 and a sterile one below it. The spikelet consists of a first glume 

 (sometimes small or absent), a second glume as long as the whole 

 spikelet, a sterile lemma, and a fertile floret. The spikelets are dorsally 

 compressed and disarticulation is always below the glumes. 



Tribe XI. PANICEAE. The glumes 

 and sterile lemma are thinner in 

 texture than the fertile lemma and 

 pcdea, which are hard or leathery. 

 The first glume is usually much 

 shorter than the second. Spikelets 

 borne in panicles or racemes. Fig. 

 20. Pages 149-175. 



Figure 20 



Tribe XII. ANDROPOGONEAE. Spikelets with 

 two equal hardened glumes, which completely 

 inclose the thin, delicate sterile lemma and fer- 

 tile floret. Spikelets borne in racemes or spikes, 

 a pair of them borne at each joint of the rachis. 

 One spikelet of each pair is perfect and fertile, 

 the other usually staminate, sterile, or rudimen- 

 tary. Fig. 21. Pages 176-183. 



Figure 21 



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