418 GEAMINE^E. (GRASS FAMILY.) 



base. — Tricuspis acuminata, Monro. From Texas to Arizona, and extending 

 into S. Colorado. 



31. DIPLACHNE, Beauv. Slender Geass. 



Ours are annuals, with flat leaves and geniculate-decumbent and branching 

 stems. 



I. D. fascicularis, Beauv. Smooth : leaves longer than the stems, the 

 upper sheathing the base of the crowded panicle-like raceme, which is com- 

 posed of many strict spikes : spikelets short-pedicelled, 7 to 1 1 -flowered : 

 flowering glume hairy-margined towards the base, with two small lateral teeth 

 as well as the short awn. — Leptochloa fascicularis, Gray, Man. 623. From 

 New England across the continent. 



32. T It I PL A SIS, Beauv. Sun> Grass. 



A tufted grass, with numerous bearded joints, and short involute-awl- 

 shaped leaves. 



1. T. purpurea, Chap. Stems ascending, 6 to 12 inches high : panicles 

 very simple, of few spikelets, the terminal one usually exserted, the axillary 

 ones included in the commonly hairy sheaths : awn much shorter than its 

 glume, seldom exceeding the eroded-truncate or obtuse lateral lobes. — Tri- 

 cuspis purpurea, Gray. Colorado (Hall Sr Harbour) ; about the Great Lakes 

 and along the Atlantic coast. 



33. PHRAGMITES, Trin. Reed. 



Tall and stout perennials, with numerous broad leaves and a large terminal 

 panicle, the silky hairs of the rhachis becoming very conspicuous as the seed 

 ripens. 



1. P. communis, Trin. Stems 5 to 12 feet high : panicle loose, nod- 

 ding ; spikelets 3 to 5-flowered ; flowers equalling the wool. — Found every- 

 where along the margins of streams and ponds. Looks like Broom-Corn at a 

 distance. 



34. MUNROA, Torr. 



Creeping annuals, very much branched from the base, with fasciculate 

 branches. 



1. M. squarrosa, Torr. Leaves 1 to 2 inches long, flat, 1 to 2 lines wide, 

 somewhat pungent, scabrous on the margin : spikelets mostly 3 : glumes al- 

 most unilateral, linear-lanceolate, keeled. — Bot. Whipple, 158. On the plains. 



35. KCELERIA, Pers. 



Tufted grasses, with simple upright stems : the sheaths often downy. 



1. K. cristata, Pers. Panicle narrowly spiked, interrupted or lobed at 

 the base: spikelets 2 to 4-flowered : flowering glume acute or mucronate: 

 leaves flat, the lower sparingly hairy or ciliate. — From California and OregOK 

 eastward to Pennsylvania. 



