evil. GRAMINEvE. 
525 
23. Hieeochloe. Florets 3, awnless ; central one perfect, diandrous ; 
barren ones lateral, triandrous. 
JJ Panicle spike-like. 
21. Koeleria. Panicle cylindrical. Spikelets without a bractea at the 
base. Glumes unequal. Outer glumella entire, pointed. Stigmas 
plumose. 
22. Sesleria. Panicle cylindrical. Spikelets without a bractea at the 
base. Glumes nearly equal. Outer toothed, with a short bristle 
at the end. Stigmas filiform. 
30. Cynosures. Panicle unilateral. Spikelets with a pectinate bractea 
at its base. Glumes equal. Outer glumella linear-lanceolate, 
mucronate or awned at the end. 
ft Spikelets broader than thick, dorsally (not laterally ) compressed. Perfect 
floret 1, its glumellas hardening on the caryopsis ; barren 0; neuter 
as large as the perfect one, of one glumella. 
9. Milium. Panicle lax, diffuse. Spikelets without bristles at the 
base, awnless. Glume 1. 
ftf Spikelets flat in front, gibbous or very convex on the back (not late- 
rally compressed). Perfect floret 1, its glumellas hardening on the 
caryopsis ; barren or neuter as large as the perfect one, of 1 — 2 glu- 
mellas. 
24. Panicum. Panicle in a racemose somewhat unilateral compound 
spike. Spikelets without bristles at the base, awned. Glumes 2 ; 
lower one the smaller. 
44. Digitaria. Spikelets without bristles at the base, awnless, forming 
a digitate or shortly racemose compound spike. Glumes 2 ; lower 
one the smaller and sometimes obsolete. 
25. Setaria. Panicle in a compound cylindrical dense spike. Spikelets 
1—3 together, surrounded by an involucre of bristles. 
*** Spikelets with 3 or more perfect florets, laterally compressed. 
Glumes 2. 
t Outer glumellas with a dorsal awn from or below the middle. 
16. Aira. Outer glumella toothed at the end; awn slender. 
33. Avena. Glumellas herbaceous but ultimately cartilaginous and 
firmly inclosing the caryopsis ; outer one with two points or 
. bristles at the summit ; its awn long, twisted. 
tf Outer glumellas with or without a terminal or subterminal awn or bristle, 
but no dorsal awn. 
J Florets not mixed with long silky hairs. 
§ Glumes about as long as the rest of the spikelet. 
17. Triodia. Spikelets racemose. Outer glumella somewhat coriaceous, 
convex on the back, hairy at the base, 3-toothed at the end, 
middle tooth straight. Stigmas plumose. 
22. Sesleria. Panicle cylindrical. Glumellas naked at the base, 
membranous ; outer one keeled, toothed, and with a short bristle 
at the end. Stigmas filiform. 
