TO THE GENERA OF THE FAMILY GRAMINEJE. IO49 



I Empty glumes of pist. fls. indurated, with 3 green terminal ligulate 

 lobes; extensively creeping grasses with pist. spikelets clustered in 



upper sheaths; e.g. = spk Bulbilis. 



// Empty glumes and habit not as above. 



7)i Very tall corn-like grasses (2-10 m. high), with rather short and 

 very broad, evenly distributed, spreading leaves; fl. gls. very long- 

 silky-hairy, e.g. = spk, (Arundo.) 



mm Habit not as above. 

 n Flowering glumes narrowed into a 3-branched awn; e.g. = spk. 



Aristida. 

 nn Flowering glumes awnless or with a simple awn (which may be 

 borne between two awn-pointed teeth). 

 o Flowering glumes, at least one of them, bearing an awn on back, 



or between the terminal teeth, or strongly 3-toothed. 

 P Awn borne on the back below the apex or apical notch; e.g. = 

 spk. except in Avena, Trisetum, and Bromus. 

 q Glumes 3. 



r Panicle spike-like, very dense. 



5 Empty glumes densely covered with woolly hairs . . (Lagurtjs.) 

 ss Empty glumes not densely woolly, sometimes villous. 



/ Empty glumes not awned Alopecurus. 



// Empty glumes awned Polypogon. 



rr Panicle open, branches long and slender. 



5 Apex of fl. glume bifid Apera. 



55 Apex of fl-. glume entire Agrostis. 



qq Glumes 4 or more, the 3d sometimes sterile. 

 r One of the two flowers awnless, one flower staminate only. 

 s Plant glabrous, awn on lower flower only, long bent and 



twisted Arrhenatherum. 



55 Plant soft-velvety; awn on upper flower only, usually hooked. 



Holcus. 

 rr At least two, usually all, of the flowers with awns. 

 5 Rachilla produced beyond the insertion of the upper flower; 

 stigmas terminal. 



t Spikelets more than 7 mm. long Avena. 



tt Spikelets 7 mm. long or less Trisetum. 



ss Rachilla not produced beyond the insertion of the upper 



flower. 

 / Spikelets many-flowered; fl. gl. about 6-8 mm. long; stigmas 



inserted below apex of ovary Bromus. 



It Spikelets 2-fld.; fl. gls. nearly glabrous Aira. 



ttt Spikelets essentially 3-fld., but the two lower fls. staminate 



or sterile, fl. glumes ciliate or silky, fragrant-aromatic 



grasses. 



u Fifth glume very acute, 3d and 4th staminate. . . SAVASTANA. 



uu Fifth glume obtuse, 3d and 4th empty.. . Anthoxanthum. 



pp Awn borne between two terminal teeth, or the apex 3-toothed. 



q Spikelets nearly sessile in the axils of the clustered rigid apical 



foliage leaves, low erect or prostrate grasses; western; 



e.g. < spk MuNROA. 



qq Spikelets in ordinary spikes or panicles. 



r Spikelets i-fld. (glumes 3), or with a rudiment of a second. 

 s Inflorescence spicate. 



/ Spikelets reflexed; e.g. < spk Atheropogon. 



tt Spikelets ascending; e.g. = spk Gvmnopogon 



ss Inflorescence paniculate; e.g. = spk ClNNA. 



rr Spikelets 2-manv-fld. (glumes 4 or more). 



s Spikelets regularly spiked, e.g. <spk Triticum. 



ss Spikelets paniculate. 



[Trichclana, with very long silky glumes, rarely has awns.) 



