North American Cypcraccfe. 309 



2 — 3 lines long, seldom more than 5 or 6-flowered, ami sometimes bear- 

 ing only one or two flowers. Scales often barren, seldom more than one 

 or two of them fructiferous, greenish, with a red stripe on each side of 

 the midrib. Bristles shorter than the nut, very slender and fragile, 

 sometimes entirely wanting. Stamens 3. Stjjlc 3-cleft about half its 

 length. iVw< whitish, often contracted at the neck, obscurely triangular; 

 or rather polygonal from the prominent longitudinal ridges which mark 

 its sides, and which are about 15 in number, with very fine transverse 

 lines. Tubercle conical-triangular, somewhat free at the base. 



Hab. Borders of ponds; generally partly under water; 

 Hudson's Bay to Florida. — June — July. 



Obs. When this plant grows in overflowed situations, its 

 culms are quite capillary, and the spikes seldom produce fruit. 

 In drier situations the culm is much firmer and wiry. Nees 

 ab Esenbeck refers to his ChcBtocijpervs iwhjmorylms, the Scir- 

 ims capillaceus of Michaux, and also the Schjnts trichodcs, H. 

 B. ^K. ; but Michaux's plant is surely nothing more than a 

 slender form of Eleocharis acicularis^ 



14. Eleocharis tenuis, Schnltcs. 



Culm filiform, quadrangular, with the sides concave ; spike 

 elliptical, somewhat acute at each end; scales ovate, obtuse; 

 bristles 2 — 3 or none ; nut obovate, triangular, with the angles 

 prominent, corrugated transversely, and somewhat papillose, 

 crowned with a minute short triangular tubercle. 



Eleocharis tenuis, Sehultes, mant. 2. p. 89. 



Seirpus tenuis, Willd. enum. hort> Beroi. 1. p. 76 ; Muhl.! gram. p» 

 21; Rcem. Si' Schult. 2. p. 127; Torr.IJl. 1. p. 44; Beck! hot. p. 425 ; 

 Big.fl. Bost. ed. 2. p. 21 ; Spreng. syst. 2. p. 205; Darlingt. ! fl. Ccst. 

 ed. 2. p. 20. 



S. quadrangulatus, Muhl. cat. ed. 2 p. 6. (not of Michx.J 



Culms scarcely thicker than a horse-hair, 8 — 12 inches long, acutely 

 quadrangular, the base clothed with one or two purple sheaths. Spike, 

 when young, rather obtuse. Scales dark chestnut-coloured, with a 

 whitish scarious margin ; several of the lowest ones larger and empty. 

 Bristles 2 — 3, short, slender and fugacious. Stjle 3-cleft. Nut of a 



