OUDER 155. GR AMINES. 381 



t inflorescence paniculate... (3) 



2 Inflorescence strictly spicate, spikes equilateral... (5) 



3 Inflorescence strictly spicate, spikes unilateral... (6) 



3 Glumes none (or minute and the stamens 6)... (a) Triho 1 



3 Glumes present, at least 1 conspicuous. . .(4) 



4 Pales of the flower thin nnd soft, often awned... (6) Tribe 2 



4 Pales of the flower coriaceous, * tipped with awns... (/) Tribe 4 



* 8wnless...(i7) Tribe 5 



6 Spikes cylindric, the spikelets condensed all around... (e) Tribe 3 



6 Spikes origmatic, spikelets sessile in rows . . . (o) Tribe 9 



6 Spikelets rounded on the back, appressed to the rachis...(</) Tribe 5 



6 Spikelets acutely keeled on the back, imbricated on each other... (z) j T 'b 10 



7 Upper tis. of the spikelet abortive. * Fls. in unilateral spikes... (x) ' " 



* Flowers paniculate... (k) Tribe 7 



7 Lower flower of the spikelet abortive... (8) 



8 Pales coriaceous, firmer in texture than the glumes. Paniculate... (g) Tribe 9 



8 Pales membranous, thinner than the glumes. Spicate... (66) Tribe 11 



9 Flowers in 2- or 4-rowed, * equilateral spikes. . . (u) Tribe 9 



* nnilateral spikes... (x) Tribe 10 



9 Flowers in panicles more or less diffuse ... (10) 



10 Pale awned at the tip or awnless...(n) Tribe 8 



10 Pale awned on the back or below the tip...(fc) Tribe 7 



i ORYZEJS. (Spikelets 1-jtoicered, panided. Glumes obsolete. Stamau\6.) 



a Flowers perfect, flattened laterally, awnless. Glumes 0. Stum. 2 or 3. Cut Grant . . . .LEKKSIA. 1 



Glumes minute. Stamens 6. Bice ORYZA. 2 



a Flowers monoecious, both kinds in the same panicle. Stamens 6. Indian Bice. ZIZAMA. 3 



Flowers monoecious, each kind in separate panicles. Stamens 512. 8 LUZIOLA. 4 



2. AGKOSTIDE/E. (Spikelels 1-jtouered, panided. Glumes and palet thin. Grain/iff.) 



6 Flowers surrounded at base with a tuft of long, silky hairs CALAMAGROSTIS. 10 



b Flowers nuked or thinly bearded at base. . .(c) 



e Glumes both long-awned and longer than the awned pule* POLYPOGON. 9 



e Glumes both awn-pointed (or minute and the pale awned) MCHLKNBERGIA. 8 



e Olumes awnless, conspicuous... ('') 



d Pale stalked in the glumes, awned on the back, monandrou*. Siceet Bted CINNA. 7 



d Pale sess. in the glumes, 3-androus, acute, awnless. Glume? shorter SPOROBOI.US. 6 



obtuse, often awned on back. Bent </. .AUROSTIS. 5 



3. PHLEOIDE^E.e Glumes united at base, awnless. Pale 1, awned ALOPKCCRUS. 11 



e Glumes distinct, mucronate. Pales 2, awnless. Timothy PHLEDM. 12 



f. Glumes distinct, pointless. Pales 2, awnless CRTPSIS. 13 



4. 8TIPACE.iE. -f Awn of the flower simple, straight, deciduous Osrzopsig. 16 



/ Awn of the flower simple, twisted, very long STIPA. 15 



/ Awn of the flower triple or 3-parted. Poverty Grass ARISTIDA. 14 



6. PANICE^E. (Spikelets 2-fltod., loicer Hotter abortive. Glumes very unequal. 9 Pale coriaceous.) 

 g Spikelet apparently 1 -flowered, the lower glume wanting and the single abortive pale 



supplying its place. Flowers spicate, unilateral PASPALUM. 17 



Flowers diffusely panicled, all alike. Millet Grass Miutiw. 18 



Flowers paniculate, 2 sorts, one under ground AMPHICARPUM. 19 



g Spikelet evidently 2-flowered, both glumes present, abortive flower neutral or f . . .(A) 



A Flowers paniculate, without awns or spines. Pale cartilaginous. Panic S PANICUM. 20 



without awns or spines. Pales herbaceous PENICILLARI A. 21 



with the glumes and pale coarsely awned. Cock-spur. . OPLISMENUS. 22 



A Flowers spike-panicled, each with an invol. of awned pedicels. Fox-tail SETARIA 23 



each with a hardened, burr-like invol. Burr ffro...CENCHROS 24 



I HALARIDK.E. f Sterile flowers 2 minute rudiments. Panicle spicate PBALARIS 25 



i Sterilo flowers 2 awned pales. Panicle spicate ~~..._.AjrrnoxATrnn;M 26 



i Sterile flowers both 2-valved, ;. Panicle open HIEROCBLOA 27 



/ AVENE^E. (Spikelets 2 - 00 -flowered, pnnicled . Glume* large. Pale awned below tht tip.) 



Ir Spikelet with 1 perfect flower and 1 awned staminate flower above. Sofl Grass. HOLCOS. 28 



below AKBHENATHERUM 31 



i .Spikelet with definitely 2 perfect flowers. Pale siibwitire, awn dorsal AHA 22 



A Spikelet with 2 or more perfect flowers. Pale 2- toothed at apex. . .(in) 



