GRAMINE^E. (GRASS FAMILY.) 605 



28. Dactylis. Glumes (rather long) and lower palet awn-pointed, herbaceous, compressed- 

 keeled. Panicle contracted in one-sided clusters. 



29-. Kceleria. Glumes (nearly as long as the spikelet) and lower palet membranaceous, 

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



37. Festuca, with grain sometimes free, may be looked for here. 



b. Lower palet awnless and pointless, blunt (except one Glyceria), the nerves parallel. 

 1. Glumes extremely dissimilar. U -3-flowered. 



30. Eatoiiia. Lower glume linear •, the upper broadly obovateaud folded round the flowers. 



2. Glumes similar in shape, but often unequal in size. 



31. Melica. Lower palet flattish-convex, many-nerved, membi-anaceous at the top, harden- 



ing on the loose grain. Fertile flowers 1-3, the upper enwrapping deformed sterile ones 



32. Glyceria, Lower palet convex or rounded on the back, 5-7-nerved, scarious at the 



tip. Spikelets maiiy -flowered ; the flowers deciduous at maturity by the breaking up of 

 the rhacbis into joiuts. 



33. Brizopyrnm. Lower palet laterally much compressed and often keeled, acute, rigid, 



rather coriaceous, smooth, faintly many -nerved. Spikelets flat, spiked-clustered. 

 37. Festuca. Lower palet slightly if at all laterally compressed, not keeled, only 1-5-nerved, 

 not cobwebby, and nearly witiiout scarious margins, acutish : otherwise as in Poa. 



34. Poa. Lower palet laterally compressed and mostly keeled, 5-nerved, membranaceous, 



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

 palet not remaining after the lower falls. Spikelets flattened. 



35. Eragrostis. Lower palet 3-nerved, keeled, deciduous, leaving the upper persistent on 



the rhachis. Spikelets flat. 



•«- +- Grain adherent to the upper palet. 



36. Briza. Lower palet rounded, very obtuse, pointless, many-nerved, flattened parallel to 



the glumes, soon ventricose, scarious-margined. Spikelets somewhat heart-shaped. 



37. Festuca. Lower palet convex on the back, acute, pointed, or awned at the tip, few-nerved. 



Spikelets terete or flattish. Styles terminal. 



38. Bromiis. Lower palet convex or keeled on the back, mostly awned or bristle-bearing- 



below the 2-cleft tip, 5-9-nerved. Styles scarcely terminal. 



* * Lowest flower of the spikelet neutral or staminate. 



39. Uniola. Spikelets very flat •, the one or more lowest flowers neutral, of a single empty 



palet. Flowers strongly compressed-keeled, crowded, coriaceous. 



40. Fliragmites. Spikelets strongly silky-bearded on the rhachis, loosely-flowered, the 



lowest flower staminate or neutral. Palets membranaceous. 



Subtribe 5. Bambusese. Culms woody and commonly arborescent. Spikelets and 

 flowers nearly as in the preceding Subtribe, awnless. 



41. Aruiitiinai'ia. Spikelets flattened, loosely 5- 14-flowered, in depauperate panicles. 



Subtribe G. Hordeinese. Spikelets 1 -several-flowered, sessile on opposite sides of a 

 zigzag jointed rhachis (which is excavated or channelled on one side of each joint), forming 

 a spike. Glumes sometimes abortive or wanting. Otherwise as in Subtribe 4. 

 * Spikelets single at each joint of the rhachis. 



42. Lepturus. Spikelets almost immersed in the excavations of the very slender rhachis, 



1-flowered. The filiform spikes usually several. 



43. Liolium. Spikelets many-flowered, placed edgewise on the rhachis of the solitary spike : 



glume only one, external. 



44. Tritscum. Spikelets 3- several flowered, placed flatwise on the rhachis of the solitary 



spike : both glumes present, transverse (right and left). 



* * Spikelets 2 or more at each joint of the rhachis : spike solitary. 

 +- Glumes anterior, forming a sort of involucre for the cluster of spikelets. 

 45- Hordeum. Spikelets 1-flowered, 3 at each joint, but the two lateral usually sterile. 

 46 Fly in us. Spikelets 1 - several-flowered, all perfect and similar. 



