TWENTY-FIBST ANNUAL MEETING. 



89 



30. Spikes solitary or paniculate, spreading or deflexed, flattened (80). 



30. Spikes triangular, racemose; spikelets much flattened 27 Spartika. 



30. Spikes racemed, slender, usually numerous 33 Leptochloa. 



31. Spikelets in dense fascicles or glomerate clusters indistinctly or not at all 



one-sided 47 Dactylis. 



31. Spikelets not as above (32). 



32. Spikes digitate at the summit of the culm, (sometimes scattering ones lower 



down); spikelets crowded 32 Eleusine. 



32. Spikes, etc., not as above (33). 



33. Spikelets with 1 (rarely 2) perfect flower and a bristle-like rudiment or awn- 



like pedicel 29 Gymnopogon. 



33. Spikelets not as above, many-flowered, narrow 39 Diplachne. 



34. Spikelets sessile and remotely alternate on long and filiform branches of the 



panicle, one (or 2) flowered and a bristle-like rudiment or an awn-like 



pedicel 29 Gymnopogon. 



34. Spikelets not as above (35). 



35. Spikelets two-flowered (36). 



35. Spikelets three to many-flowered (41). 



35. Spikelets one-flowered, at least but one flower perfect (52). 



36. Swamp grasses, very tall (7-12 ft.), with long and broad leaves 36 Phragmites. 



36. Not as above (37). 



37. Second glume broadly obovate, not keeled 41 Eatonia. 



37. Second glume not broadly obovate (38). 



38. Flowering glumes with a fine dorsal awn below the middle 25 Deschampsia. 



38. Flowering glumes destitute of awns (39). 



39. Palet about equaling the flowering glume (40). 



39. Palet shorter than its glume, ciliate on keel and apex 43 Melica. 



40. Spikelets usually more than 2-flowered, somewhat compressed 4S Poa. 



40. Spikelets usually one (rarely 2) flowered, not compressed 19 Sporobolus. 



41. Flowering glumes with a flattish, twisted, bent awn 2(> Danthonia. 



41. Awns absent or not as above (42). 



42. Swamp grasses, very tall (7-12 ft.), with long and broad leaves 3fi Phragmites. 



42. Not as above (43). 



43. Spikelets in dense fascicles or glomerate clusters at the ends of the short 



branches of a close, short panicle 4(> Dactylis. 



43. Spikelets not as above (44). 



44. Drooping flat spikelets an inch long and nearly half an inch wide 4.5 Uniola. 



44. Spikelets not as above (45). 



45. Flowering glumes 3 to 5 or many-nerved, more or less involute, the upjjer 



two or more empty or imperfect 43 Melica. 



45. Flowering glumes 5 to many-nerved, the upper one empty (46). 



45. Flowering glumes 3 or one-nerved (47). 



46. Flowering glumes rigidly membranaceous or subcoriaceous, faintly many- 



nerved, much compressed and keeled ; spikelets many-flowered dioecious, 46 Distichlis. 



46. Flowering glumes 5-7-nerved, often with a few loose or webby hairsat base; 



spikelets somewhat compressed, usually 2-5-ttowered 48 Poa. 



46. Flowering glumes obtuse, more or less denticulate at the apex, not keeled 

 but rounded on the back, 5 to 9-nerved, the nerves separate and all van- 

 ishing before reaching the apex ; spikelets terete or flattish 49 Glyceria. 



46. Flowering glumes narrow, rounded on the back, more or less distinctly 3-5- 



nerved, acute or tapering into a straight awn , 50 Festuca. 



46. Flowering glumes rounded on the back or compressed and keeled, 5-9- 



nerved, acute or awned from below the mostly 2-cleft apex, grain adher- 

 ing to the palet 51 Bromos. 



47. Second glume broadly obovate, shorter than the spikelet, not keeled, 



3-nerved 41 Eatonia. 



47. Second glume not broadly obovate (48). 



48. Flowering glumes not keeled but rounded on the back, (at least below,) the 



palet broad (49). 

 48. Flowering glumes keeled (.50). 



