Order 156.--GRAMINE^. »?7l 



TEIBE3 AND GENERA. 



S Splkelct 1-flowered -witli no apparent rudiraent of a second 3. (2) 

 S Spikelet 2-flowere(l, ono of the fls. sterile or rudimentary. (7) 



S Spikelet 8-floworcd, the 2 lower (lateral) lis. sterile or rudimentary, (i) Tribo 6 



S Spikelet 2— oo -flowered, 2 or more of the fls. perfect. (8) 

 2 Inflorescence paniculaco. (3) 



2 Inflorescence strictly spiciite, spikes equilateral. (5) 

 2 Inflorescence Btrictly spicate, spikes unilateral. (6) 



3 Glainc3 none (or minute and the stamens 6). (a) Tribo 1 



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



4 Pales of the flower thin and soft, often awaed. (6) Trtbo 3 



4 Pales Of the flower coriaceous,— tipped with awns, (f ) Tribe 4 



— awnlcss. (g) Tribe 6 



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



5 Spikes prismatic, spikelets sessile in rows, (v) Tribe 9 



6 Spikelets rounded on the back, uppressed to the rachls. (g) Tribe 5 



6 Spikelets acutely keeled on the back, imbricated on each other, (x) | t iK«in 



7 Upperfls.of the spikelet abortive.— Fls. in imilateral spikes, (x) [ IrlbclO 



—Fls. paniculate, (k) Tribe 7 



7 Lower flower of the spikelet abortive. (8) 



• 8 Pales coriaceous, firmer in texure than the gls. Paniculate, (g) Tribo 6 



8 Pales mcmbmnoiis, thinner than the glumes. Spicate. (bb) Tribe 11 



Flowers in 2 or 4-rowed, — equilateral spikes, (v) Tribe 9 



— unilateral spikes, (x) Tribe 10 



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



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



10 Palo awned on the back or below the tip. (k) Tribe 7 



Tr. 1. OKTZE^. (Spikelets 1-flowered, panicled. Gls. obsolete. Stam. 1— G.) 



u Flowers perfect, flattened laterally, awnless. — Gl. 0. Stam. 2 or 3 Lekrsia. 1 



— Gl. minute. Stam. 6 Ortza. 2 



a Flowers monojcious, conves on the back, awned. Stamens 6 Zizawia. 8 



Tr. 2. AGEOSTIDE^E. (Spikelets 1-flrd., panicled. Gl. and pales thin. Grain free.) 



b Fls. surrounded at base with a tuft of long, silky hairs Calamaguostis. 9 



b Fls. naked or thinly bearded at base, (c) 



C Glumes both long-awned and longer than the awned pales. .'. Polypogon. 8 



C Glumes both awn-pointed (or minute and the pale awned) MuiiLnNBEBGiA. 7 



C Glumes awnless, conspicuous, (d) 



d Pale stalked in the glumes, awned on the back, monandrous Cinwa. ft 



d Palo sess. ia tho gls. 3-androus, — acute, awnless. Gls. shorter SponoBOLtra. 5 



— obtuse, often awned on the back Agrostis. 4 



Te, 3. PHLEOIDE-^ — e Gls. united at base, awnless. Pale 1, awned Alopecurus, 10 



— e Gls. distinct, mucronate. Pales 2, awnless Piileum. 11 



Tb. 4. STIPACEjE.— f Awn of the flower simple, straight, deciduous Ortzopbis. 14 



— f Awn of the flower simple, twisted, very long Stifa. 18 



— f Awn of the flower triple orS-parted Abistida. 13 



Tb. 6. PANICIE J3. (Spkl. 2-fl., lower fl. abortive. Gls. very unequal. B Pale foriaceous.) 

 g Spkl. apparently 1-flowerod, the lower glume wanting and the single abortive pale 



supplying its place.-Fla. spicate, unilateral Pabpalum. 16 



—Fls. diffusely panicled, all alike Millium. 16 



—Fls. paniculate, 2 sorts, one under ground AjjFHiCABPaM. 17 



g Spkl. evidently 2-flowered, both gl, present, abort, fi. neutral or 5 . (h) 



h. Fls. paniculate,— without awns or spines. Gl. very unequal Panjcum. 18 



— with the glumes and pale coarsely awned Opl[Smektt& 19 



h Fls. spike-panicled, — each with an invol. of awned pedicels Setaria. 20 



—each with a hardened, burr-like invol Cbnchrus. 21 



Te. 6. PLALAEIDE^.— i Sterile fls. 2 minute rudiments. Panicle spicate Phalaris. 22 



— i Sterile fls. 2 awned pales. Panicle spicate. . . . Ahthoxanthuu. 28 



— i Sterile fls. both 2-valved, J. Ponicle open Hieeochloa. 24 



Ttt. 7. AVENEiE. (Spkl. 2— co-flrd., panicled. Gls. large. Pale awned below the tip.) 



k Spikelet with 1 [lerf. flower and 1 awned stam. flower— above Holotts. 25 



—below. § AERHENATnERUM. 28 



k Spikelet with definitely 2 perfect fls. Pale subentire, awn dorsal. Aiea. 26 



k Spikelet with 2 or mora perfect fls. Palo 2-toothed at apex, (m) 



