Okder 156.— GRAMINE^. 7*71 



tribes and geneea. 



S Spikelet 1-flowered with uo npparent rudiment of a second 3. (2) 

 § Spikelet 2-flowered, one of the fla. sterile or rudimentary. (7) 



§ Spilcelet 8-flowered, the 2 lower (lateral) fls. sterile or rudimentary, (i) Trite 6 



§ Spikelet 2— co -flowered, 2 or more of the fls. perfect. (9) 

 2 Inflorescence paniculate. (3) 



2 Inflorescence strictly spicate, spikes equilateral. (5) 

 2 Inflorescence strictly spicate, spikes unilateral. (6) 



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



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



4 Pales of Iho flower thin and soft, often awaed. (6) .' Tribe 2 



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



— awnless. (g) Tribe 5 



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



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



6 Spikelets rounded 'iVn tUc back, upinusi^i-'il tu the rachis. (g) Tribe 5 



6 Spikelets acutely keeled on the back, imbricated on each other, (x) | T 'h 10 



7 Upper fls. of the spikelet abortive. — Fls. in unilateral spikes, (x) [ 



* ' —Fls. paniculate, (k) Tribe 7 



7 Lower flower of the spikelet abortive. (8) 



8 Pales coriaceous, firmer in texure than the gls. Paniculate, (g) Tribe 5 



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



9 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 awned at the tip or awnless. (u) Tribe 8 



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



Te. 1. OETZEJi:. (Spikelets 1-flowered, panicled. Gls. obsolete. Stam. 1— G.) 



a Flowers perfect, flattened laterally, awnless. — GI. 0. Stam. 2 or 3 Leersia. 1 



— Gl. minute. Stam. G Oetza. 3 



a Flowers monoecious, convex on the back, awned. Stamens 6 Zizania. 3 



Tk. 2. AGKOSTIDE^. (Spikelets J-flrd., panicled. Gl. and pales thin. Grain free.) 



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



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



e Glumes both long-awned and longer than the awned pales Poltpogon. 8 



C Glumes both awn-pointed (or minute and tho palo awned) MunLENBERQiA. 7 



C Glumes awnless, conspicuous, (d) 



d Pale stalked in the glumes, awned on the back, monandroua Cinna. 6 



d Palo sess. in the gls. 8-androus, — acute, awnless. Gls. shorter Spokobolus. 5 



— obtuse, often awned on the back. . . -Agbostis. 4 



Ta. 3. FHLEOIDE^.— e Gls. united at base, awnless. Pale 1, awned ALOPECtrnus. 10 



— e Gls. distinct, mucronate. Paloa 2, awnless Phleum. 11 



Te. 4. STIPACEiE.— f Awn of the flower simple, straight, deciduous OnYZOPSia. 14 



— f Awn of the flower simple, twisted, very long Stipa. 13 



— f Awn of tho flower triple or 8-parted , Aeibtid a. 12 



Tk. 5. PANICIE^. (Spkl. 2-fl., lower fl. abortive. Gls. very unequal, ii Palo coriaceous.) 

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



supplying its place.— Fls. spicate, unilateral Paspalum. 15 



—Fls. diffusely panicled, all alike Millium. 16 



—Fls. paniculate, 2 sorts, one underground AMPnioAEPDii. 17 



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



h Fls. paniculate,— without awns or spines. Gl. very unequal Pakicum. IS 



— ^^vith the glumes and pale coarsely awned Oplismbsus. 19 



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



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



Te. 6. PLALAfilDEiE.— i Sterile fls. 2 minute rudiments. Panicle spicate Phalaeis. 22 



— ^i Sterile fls. 2 awned pales. Panicle spicate Anthosantuum. 23 



i Sterile fls. both 2-valved, $. Panicle open HiKKOcnLOA. 24 



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



k Spikelet with 1 perf. flower and 1 awned stam. flower— above Holcus. 25 



—below § ARRHENATHKErM. 2S 



k Spikelet -with definitely 2 perfect fls. Pale suhentire. awn dorsal Aika. 26 



J; Spikelet with 2 or more perfect fls. Pale 2-toothed at apex, (m) 



