576 
CXIII. GRAMINEiE 
Spikelets in more or less spreading, loose panicles. Rhachilla not prolonged, 
except in Deyeuxia. 
Spikelets awned. 
Spikelets | in. Empty glumes unequal. Flower- 
ing glume rigid, tip produced in a long, 3-branched 
awn 22. Aristida. 
Spikelets ^ in. Empty glumes nearly equal. Fruit- 
ing glume narrow, acuminate, tip produced in a 
long, simple awn .23. Stipa. 
Spikelets 1 in. Empty glumes nearly equal. Fruit- 
ing glume obovoid or rather broad, tip narrowed 
into a long, simple awn 24. Oryzopsis. 
Spikelets minute. Flowering glume shorter than the 
empty glumes, hairy, thin, shortly awned on the 
back, tip truncate, minutely jagged . . .30. Agrostis 
Spikelets minute. Flowering glume stiff, hairy on 
the lower half, narrowed into a long, slender awn . 31. Muehlenbergia. 
Spikelets £ in., narrow. Empty glumes unequal, 
long-pointed. Flowering glume much shorter, 
awned, enveloped in a tuft of long, silky hairs . 32. Calamagrostis. 
Spikelets £ in. Rhachilla terminating in a tuft of 
hairs. Flowering glume thin, tip 2-lobed, awned 
in the cleft 33. Deyeuxia. 
Spikelets awnless. 
Spikelets ^ in. Empty glumes nearly equal, thin. 
Flowering glume thick, smooth, hard, shining . 25. Milium. 
Spikelets minute. Glumes thin. Empty glumes 
unequal. Flowering glume acute. Grain free 
from the glumes ; pericarp loose .... 29. Sporobolus. 
Spikelets minute. Flowering glume shorter than 
the empty glume, thin, glabrous, tip truncate, 
minutely jagged 30. Agrostis . 2 
Tribe VI. Avenese. Spikelets ^-1 in., in panicles, narrow, 
terete, 2-5 -flowered. Flowering glume long-awned. 
Flowering glume 2-4-lobed at the tip, awned on the 
back. Grain adherent to the pale . . . .34. Arena. 
Flowering glume produced in 2 long points, awned in 
the cleft. Grain free . . .... 35. Danthonia. 
Tribe VII. Chloridese. Spikelets small or minute, sessile in 
2 rows along one side of the usually digitately arranged spikes. 
Spike solitary. Spikelets 3-10-flowered. Empty 
glumes very unequal. Flowering glume toothed and 
awned at the tip ...... 36. Tripogon. 
Spikes 2-5 in a cluster. Spikelets 1 -flowered, not 
awned. Empty glumes nearly equal . . .37. Cynodon. 
Spikes 4-7 in a cluster. Spikelets 3-6-flowered, not 
awned. Empty glumes unequal .... 38. Eleusine. 
Tribe VIII. Festueese. Spikelets in spreading or contracted 
panicles, rarely in spikes, 3- to many-flowered or sometimes only 2- 
flowered in Koeleria and in Eragrostis interrupta, stalked or rarely 
sessile. Rhachilla usually jointed below each fertile flowering 
glume, often prolonged, tip naked or bearing 1-3 rudimentary 
glumes. 
1 Species 1 and 2. 2 Species 3 and 4. 
