569 
gramine^e. (grass family.) 
9. Muhlenbergia. Lower glume smaller. Pale® chiefly hairy- 
bearded at the base, the tip of the lower one mucronate- 
pointed or produced into a slender bristle or awn. Stamens 3. 
10. Brachyelytrum. Lower glume nearly obsolete, the upper mi¬ 
nute. Lower palea long-awned from the tip; the upper 
grooved on the back and bearing a long and slender naked 
pedicel of an abortive second flower. Stamens 2. 
— — — Glumes and pale® not bristle-pointed. Flower surrounded by 
a conspicuous tuft of downy hairs at the base. 
11. Calamagrostis. Lower palea mostly awned on the back. 
* * * (StIpe^e.) Pale® coriaceous, or indurated in fruit, commonly 
shorter than the membranaceous glumes, on an obconical rigid 
callus; the lower involute, closely inclosing the upper and the 
grain, 1-3-awned at the apex. Squamul® mostly 3. Inflores¬ 
cence racemose or panicled: spikelets usually large. 
12. Oryzopsis. Awn simple, jointed with the tip of the elliptical 
lower palea, deciduous, not twisted. 
13. Stipa. Awn simple, twisted near the base: pale® cylindrical. 
14. Aristida. Awn triple. Upper palea very short. 
*** Nos. 50 - 52, though awnless, would apparently belong here. 
Tribe 3. CHLORIdEyE. — Spikelets (rarely 1-flowered, usually) 
several-flowered, with the upper flowers imperfect, disposed in 
one-sided spikes ! Glumes persistent, the upper one looking 
outward. Rachis (axis) jointless. Spikes usually racemed or 
digitate. Stamens 2 or 3. 
* Spikelets strictly 1-flowered. 
15. Spartina. Spikelets imbricated, 2-ranked, flat: spikes alternate. 
* * Spikelets 1^-flowered, viz., with one perfect and one imperfect 
neutral flower. 
16. Bouteloua. Lower palea 3-pointed or 3-awned at the apex. 
17. Gymnopogon. Lower palea and the rudiment 1-awned. 
18. Cynodon. Flower and rudiment awnless: spikes slender, digitate. 
* * * Spikelets several-flowered. (Pericarp more or less loose.) 
19. Eleusine. Spikes digitate: spikelets imbricate-crowded, awnless. 
20. Leptochloa. Spikes racemed, slender. Lower palea pointless 
or awned. 
Tribe 4. FESTUCI # NE^E. Spikelets several- (few-many-) flow¬ 
ered, panicled ; the uppermost flower often imperfect or abor¬ 
tive. Pale® pointless, or the lower sometimes tipped with a 
straight (not twisted nor deeply dorsal) awn or bristle. Sta¬ 
mens 1-3. Squamul® 2. 
* Pale® free from the smooth grain. (Lower flowers perfect.) 
— Lower palea 2- 3-cleft and pointed, or awned at the apex. 
48* 
