256 GRAMINEJ-:. 



Lower palet usually beaiinj,' on tlie hack or k-twecii its teetli a twisted bent or straiglit 

 awn. Ovary bonietinK's liairy at toji. 



♦ Sjiikelets with two or more lower llorets perfeet. 



32. Danthonia. Spikelets several-tlowered. Lower jialet rounded on the back. Awn formed 



Irom till! three uniteil middle nerves, proeeediug from the elelt at the ajie.x. 



33. Aveua. Spikeht 'i-several-llowered. Lower palet rounded on the back, •2-lootlied at tip. 



Awn Irom the nddiiervc only. 

 3L Trisetum. Spikelet 2-several-llowered. Lower i)alet compressed and keeled, 'i-toothed or 

 2-pi)inted at apex. Awn from near the cleft, fiom the nddiiei ve only. 



35. Aira. Sjiikelet 2-tlowered, with or without a rudiment of a third liower. Lower floret 



awiied from near the base. 



* * Spikelets 2-flowered, with one flower staniinate. 



36. Arrhenatheruni. Lower flower stiinnnate, awncd ; ujiper }ierfeet and usually awidess. 



37. Holcus. Lower flower jierfect, awnless; upper staminate and awned. 



Subtribe VL FESTUCACE^. Spikelets panieled, several -(rarely 2-) many-flowered, the 

 rhachis usually prolonf,'ed and bearing an imperfect floret or a bristle. Palets pointless, 

 or the lower tipped with a straight and (except in JJruiitus) tciuiinal awn. 

 * Abortive flowers of several empty palets in a separate spikelet from the perfect ones. 



38. Lamarckia. Paidcle unilateral, spike-like. 



* ♦ Abortive or standnate flowers in the same spikelet with tlie perfect ones. 

 -1- liOWer 1 or 2 florets standnate or nculial. 



39. Pliragmitea. Spikehts in an amj.le ]ianiclc, with 1 staudnalc floret below 2 to 4 iierfect 



ones; riiM.his l>eanl,-d with lung hairs. 



40. Eremochloo. SpUahts in a short ncaily simple panicle, with 2 neutral florets below on(! 



fertile one, beyond which is a triple hairy rudiment. 

 +- +- Lowest flowers all perfect : grain not adherent to the palets : joints of the rhachis bearded 

 only in I'rinisjiis. 



41. Tricuspis. Lower palet bearded on the 3 nerves, one or all of whicli project into short 



awns. 

 ++ Lower palet pointed, awned or acute, the nerves, when present, running into the point. 



42. Dactylis. Glumes and lower palets herbaceous, awn-pointed, compressed-keeled. Spikidets 



in ilense 1-sided clusters in a 1 -sided panicle. 



43. Koeleria. Glumes aiui lower palet membranous, keeled, acute or mucronatc. Panicle con- 



trauted, spike-like. 

 +t ++ Lower palet pointless and awidess (except in Mdka), blunt, tlie nerves parallel. 

 = Lower glume 1-nerved, the upper 3-nerved. 



44. Eatonia. Glumes very iinlike, the upper much broader than the linear lower one and 



wrapped around the flowers. 



= = One or both glumes 5-nerved or more. 



45. Melica. Lower palet flatfish on the back, 7-nerved or more, mend)ranous at tip. Fertde 



flowers 1 to 3, the upjter enwraj)ping th(! 1 to 3 imiierlect ones. 

 4o. Distichlis. Lower jialet much compressed laterally, many-nerved, somewhat coriaceous. 

 Elowi'rs diacious. 



= = = Glumes 1 -3-ncrved. 



47. Lophochlcena. Low.r palet prominently 7-nerved, its nddnerve jiroduccd as an awn at the 



2-lootlicd or truncate scarious apex. U]iper palet appendagcd on the nerves. (Jlumes 

 much shoiter tiian the florets. 



48. Grlyceria. Lower palet rounded on the back, the 5 to 7 nerves not reaching the scarious 



mostly blunt apex. S]iikelets many-flowered, deciduous at maturity, the rhachis break- 

 ing up into joints. 



49. Atropis. Lower jialet chartaceous, convex or rounded on the back, faintly 5-nerved, the 



nerves not reaching the obtuse subdenticulati; or mucronulate ajiex. 



50. Poa. Lower jialct laterally comjircssed, mostly keeled, 5-ncrved, miMnbranous, the margins 



or nerves below with cobwebby hairs or pubescent; upiK'r ])alet falling with the lower. 



51. Eragrostis. T,ower palet 3-nerved, keidcd, deciduous, leaving the persistent upper one, 



.Spikrh-t flattened, usually many-flowered. 



52. Steiiochloa. Glumes long and nariow, much exceeding the 2 or 3 deciduous florets. Lower 



palet 3-nerved. 



-i- +- Lowest flowers all jicrfect : grain adherent to the palct.s. 



53. Briza. Lower i)alet rounded, very ol)tu.sc, pointless, mauy-iierved, becunnng ventricose. 



Spikelets somewhat heart-shaped. 



