418 GRAMINE^. (GRASS FAMILY.) 



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

 into S. Colorado. 



31, DIPLACHNE, Beauv. Slender Grass. 



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

 stems. 



1. 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 11 -flowered: 

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

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

 New England across the continent. 



32. TRIPLASIS, Beauv. Svnd 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 ^- 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. MUISTROA, 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, interru|»ted or lobed at 

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

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

 eastward to Pennsylvania. 



