GBAMINEJE. (GRASS FAMILY.) 537 



* * Sp kelets imperfectly several-flowered, but only one perfect flower, and this internediate. 



the one or two below it, and as many above, neutral. 



17. CTENIUM. Spikelets closely imbricated on one side of the axis of a single curved spike. 



* * * Spikelets with one perfect flower below and one or more neutral ones or rudiments above. 



18. BOUTELOUA. Lower palea 3-cleft and pointed or 3-awned at the apex. Spikes dense. 



19. GYMNOPOGON. Lower palea and the rudiment 1-awued. Spikes filiform, racemed. 



20. CYNODON. Flower and the rudiment awnless. Spikes slender, digitate. 



* * * Spikelets several-flowered ; more than one of the lower flowers perfect and fertile. 

 t- Spikes digitate at the summit of the culm, dense. 



21. DACTYLOCTENIUM. Glumes compressed-keeled ; outer one aw ned : lower palea pointed 



22. ELEUSINE. Glumes and palea both awnless and blunt. 



- ~ Spikes racemed, slender. 



23. LEPTOCHLOA. Spikelets loosely spiked. Lower palea pointless or awned at the tip. 

 gubtribe 4. FESTUCINE^:. Spikelets several- (few -many-) flowered, panicled ; the upper- 

 most flower often imperfect or abortive. Palea? pointless, or the lower sometimes tipped 

 with a straight (not twisted nor deeply dorsal) awn or bristle. Stigmas projecting from 

 the side of the flower. Stamens 1-3. 



* Culms herbaceous. Spikelets with the lower flowers all perfect. 



- Grain free from the paleae. (Also free in one or two species of No. 36.) 



*+ Joints of the rhachis of the spikelet at the insertion of each flower, or the whole rhacliis, 



bearded. Palese convex, not laterally compressed Glumes and paleae membranaceous. 



24. TKICUSPIS. Spikelets 3 - many -flowered. Lower palea hairy -fringed on the 3 nerves, one 



or all of which project into awns or mucronate tips, mostly from notches or clefts. 

 26. DUPONTIA. Spikelets 2 - 3-flowered. Lower palea scariou*, entire and awnless. 



H- -H- Rhachis of the spikelet and base of the flower not bearded. 

 1T Lower palea 1-poiuted. awned, or acute, the nerves when present running into the point. 



26. DiARRHENA. Glumes (short) and the rigid-pointed lower 3-nerved palea coriaceous, 



convex-boat-shaped. Stamens 2. Pericarp cartilaginous, large. Panicle loosely few- 

 flowered. 



27. DACTYLIS. Glumes (rather long) and lower palea awn-pointed, herbaceous, compressed- 



keeled. Panicle contracted in one-sided clusters. 



28. KCELERIA. Glumes (nearly as long as the spikelet) and lower palea membranaceoufl 



keeled, acute or mucronate, or rather blunt. Panicle contracted, spike-like. 



If 1f Lower palea awnless and pointless, blunt (except one Glyceria), the nerves parallel. 



a. Glumes extremely dissimilar, 1J - 3-flowered. 



29. EATONIA. Lower glume linear ; the upper broadly obovate and folded round the flower* 



b. Glumes aUk , but often unequal in size. 



80. MELICA. Lower palea flattish-convex, many-nerved, membranaceous at the top, hard 



ening on the loose grain. Fertile 'Sowers 1-3, the upper enwrapping some deform 

 s*eril3 flowers. 



81. GLYCERTA. Lower palea convex or rounded on the back, 5 - 7-nerved, scarious at tb 



tip. Spikelets many-flowered ; the flowers commonly deciduous at maturity by th 

 breaking up of the rhachis into joints. 



82. BRIZOPYRUM. Lower palea laterally compressed and often keeled, acute, rigid, rathei 



coriaceou? smooth, faintly many-nerved. Spikelets flat, spiked-clustered. 

 23. POA. Lower palea laterally compressed and mostly keeled, 5-nerved, membranaceoua 



scarious-margined, the margins or nerves below often cobwebby or pubescent : th* 



upper palea not remaining after the lower falls. Spikelets flattened. 



34. ERAGROSTIS. Lower palea 3-nerved, keeled, deciduous, leaving the upper persistent OK 

 . the rhachis. Spikelets flat. 



- +- Grain aSherent to the upper palea. 

 85. BRTZA. Lower palea rounded and very obtuse, pointless, many-nerved, flattened parallel 



to the glumes, becoming ventricose, broadly scarious-margiued. Spikelets compressed 



somewhat heart-shaped. 

 oG. FESTUCA. Lower palea convex on the back, acute, pointed, or awned at the tip, few 



nerved. Spikelets terete or flattish. Styles terminal. 



