GRAMINEE 715 
awned hairy palet. 
8 Hierochloa Spikelets 3-flowered, the lateral ones staminate. 
TrisE vy AGrRosTipEa Spikelets all hermaphrodite and fertile, 
with 3 glumes, the first 2 empty. Rachella sometimes prolonged 
behind-the pales into a naked or plumose bristle. 
* Flower sessile within the glumes. 
9 Coleanthus Spikelets in small umbellate clusters, all perfect. 
10° Sporobolus Spikelets in contracted or open panicles, all perfect. 
* * Flower raised weet the glume onashort rounded or stalk- 
like base. 
Glumes long-awned. 
11 Polypogon Glumes much longer than the flower. 
+ + Glumes mostly awnless. 
12 Agrostis Lower PRES exceeding the very thin obtuse palets: inflor- 
escence spike-like to open paniculate, 
13 Gasrripium Inflorescence spike-like: glumes with a shining ventri- 
cose base. 
14 Cinna Flower distinctly stipitate: flowering glume short-awned be- 
low the tip. 
15 Muhlenbergia Flowers mostly bearded at base, early deciduous: 
_ flowering glume awned from the apex. 
+ + + Flowers with a more or less conspicuous tuft at hairs at 
base, shorter than the glumes. 
16 Calamagrostis Spikelets 2-flowered and mostly with the rudiments 
of a second flower present: palet awned from below the apex. 
Trine Iv CHLORIDEX Spikelets one, to several-flowered, in 
simple one-sided spikes. upon a jointless rachis. 
+ Spikelets one-flowered. 
17 Spartina Spikelets much flattened laterally, in 2 rows upon one side 
of a 3-angled rachis: spikes racemed. 
18 Beckmannia Spikes panicled: spikelets o-flowerad, or by sbettion 
1-flowered, upon one side of a flattened rachis. 
* * Spikelets 2-flowered or more, one flower perfect with one or 
more imperfect or neutral ones above it. 
. 19 Bouteloua Flowering glumes 3-cleft and 3-awned at the apex : im- 
perfect flowers often reduced to these awns. 
20 Exxvusine Spikes digitate at the summit of the stem: spikelets sev- 
eral-flowered. 
Trise vy Saipacem Spikelets strictly one-flowered. Flowers 
with a sharp-pointed callus at base, deciduous. Flowering glume 
wrapped around the flower and palet, coriaceous and indurated 
in fruit and terminated by a simple or triple awn. 
21 Stipa Awn simple, long, twisted below, not caducous. 
22 Oryzopsis Awn simple, caducous: flower clothed with long silky hairs. 
