Bulletin No. 205 [March, 



mm. Florets not stipitatc ; lem- 

 ma awnless; panicle not 

 drooping. 



26. Sporoholus 

 gg. Spikelets with 1 or 2 staminate or rudimentary flor- 

 ets below the perfect one (first glume wanting in 

 Paspalum and in some species of Syntherisma, the 

 sterile lemma simulating a second glume). 

 h. Spikelets laterally compressed; glumes strongly 

 keeled; sterile florets falling attached to the 

 perfect floret. 

 i. Plants grayish-velvety thruout; one floret be- 

 low the perfect one, staminate; perfect 

 floret with a hooked awn on the back. 



32. Notholcun 



ii. Plants glabrous thruout; two florets below 



the perfect one. 



j. Panicle open; lower florets staminate; 



plants fragrant. 16. Torresia 



jj. Panicle contracted or spike-like; lower 



florets reduced to minute scales. 



15. Phalaris 



hh. Spikelets dorsally depressed; glumes not keeled; 



spikelets falling entire; fertile floret indurate. 



i. Spikelets subtended by 1 to several slender 



bristles, in a narrow spike-like panicle. 



11. Chaetochloa 

 ii. Spikelets not subtended by bristles. 



j. Spikelets subsessile along one side of a 

 slender axis; first glume obsolete or 

 minute, 

 k. Eaeemes subdigitate; fruit subin- 

 "durate with a flat, white, hyaline 

 margin; spikelets compressed, bi- 

 convex; annuals. 6. Syntherisma 

 kk. Eaeemes solitary or racemose; fruit 

 indurate, the firm margin inroUed; 

 spikelets plano-convex; first glume 

 obsolete; perennials. 8. Pdspalum 

 jj. Spikelets in open or compact panicles, 

 k. Floret subindurate; margins of lem- 

 ma hyaline, flat. 7. Leptoloma. 

 kk. Floret strongly indurate ; margins of 

 lemma firm, inrolled, at least at 

 base. 

 1. Sterile lemma awned or strong- 

 ly mucronate ; fruit pointed ; 

 spikelets short-pediceled in 

 clusters; coarse annuals. 



10. EchinocMoa 



11. Sterile lemma awnless; fruit 



not pointed; spikelets usually 



long-pediceled. 9. Panicum 



if. Spikelets 2- to miiny-flowoied ; sterile florets, if any, 



above the perfect ones (except in Uniola, Fig. 227). 



g. Glumes exceeding or equaling the florets (except in 



Sphenopholis and Koeleria; in these at least the 



second glume is usually longer than first floret), 



usually papery and shining. 



h. Spikelets at least 8 mm. long. 



i. Florets 2 to 4, awned from the back (awn 

 rudimentary in cultivated oats). 



