gramine^e. (grass family.) 567 



4. U. nitida, Baldw. Panicle short, of few rigid spreading branches ; 

 spikelets (6" -8" long) oblong, 6 - 8-flowered ; palese equal, the lower acute, 

 serrulate near the apex ; stamen 1. — Swamps, Florida, Georgia, and westward. 

 Aug. — Culms slender, l°-2° high. Leaves linear, smooth. 



37. PHRAGMITES, Trim Reed. 



Large perennial marsh grasses, with broad and flat leaves and panicled spike- 

 lets. Spikelets 3 - 6-flowered, with the rachis bearded with long and silky hairs. 

 Lowest flower with a single stamen and imperfect ovary, the others triandrous 

 and perfect. Glumes unequal, pointed. Lower palea narrowly awl-shaped, 2-3 

 times as long as the 2-cleft upper one. Stigmas 2. Grain free. 



1. P. communis, Trin. Culms 5° -8° high; leaves numerous, l'-2' 

 wide ; panicle diffuse, nodding ; spikelets 3 - 5-flowered, about as long as the 

 white hairs of the rachis. — Deep river marshes near the coast, Florida, and 

 northward. Sept. 



38. ELYMUS, L. Lyme-Grass. 



Coarse flat-leaved perennial grasses, with rigid erect culms, bearing a single 

 6pike of 2 - 7-flowered spikelets, arranged 2 - 4 in a cluster at each joint of the 

 zigzag rachis. Glumes 2, placed side by side before the spikelets, coriaceous, 

 unequal-sided, mostly awned. Palese of the same texture as the glumes, the 

 lower convex on the back, tapering into a rigid awn ; the upper enclosing the 

 linear hairy-tipped grain. Stamens 3. Stigmas 2. 



1. E. Virginicus, L. Spike dense, erect (3' long), the base usually 

 included in the dilated sheath of the uppermost leaf; spikelets 2 -3 in a cluster, 

 2 - 3-flowered, smoothish, short-awned ; glumes lanceolate, strongly nerved. — 

 River-banks, Florida, and northward. July and Aug. — Culms 2° - 3° high. 

 Leaves rough. Sheaths smooth. 



2. E. Striatus, Willd. Spike dense, erect or slightly nodding (3'- 5' long), 

 long-peduncled ; spikelets 2-3 in a cluster, 1 -3-flowered, hairy, long-awned ; 

 glumes linear-subulate, long-awned, much longer than the flowers. — Rocky 

 woods and banks in the upper districts, and northward. July - Sept. — Culms 

 slender, 2° high. Leaves and sheaths smooth or pubescent. 



39. GYMNOSTICHUM, Schreb. 



Spikelets 2 - 3 on each joint of the rachis, raised on a short and thick stalk. 

 Glumes none, or a single awn-like rudiment. Otherwise as in Elymus. 



1. G. Hystrix, Schreb. Spike erect, 3' - 6' long, lax-flowered ; spikelets 

 yellowish, 3 - 4-flowered, smooth or rough-hairy, long-awned ; leaves and sheaths 

 smoothish. (Elymus Hystrix, Z.) — Upper districts, Georgia, and northward. 

 July. — Culms 2° - 3° high. Rachis 2-edged. 



