418 GRAMINEJE. (GRASS FAMILY.) 



base. Tricuspis acuminata, Munro. From Texas to Arizona, and extending 

 into S. Colorado. 



31. DIPLACHNE, Beauv. SLENDER GRASS. 



Ours are annuals, with flat leaves and geniculate-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. From 

 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 $r 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. MUNRO A, 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. 



36. 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 Oregon 

 eastward to Pennsylvania. 



