SEDGE FAMILY. 

 19. Eleocharis tenuis (Willd.) Schultes. Slender Spike-rush. (Pig. 



Scirpus tenuis Willd. Enum. i: 76. 1809. 

 Eleocharis tenuis Schultes, Mant. 2: 92. 1824. 



Perennial by rootstocks, culms tufted, filiform, 

 mostly erect, 4-angled with concave sides, S'-io 7 tall. 

 Upper sheath obliquely truncate, toothed on one 

 side; spikelet narrowly oblong, mostly acute, many- 

 flowered, thicker than the culm, $,"-" long, about 

 i x/ in diameter; scales thin, obovate or ovate-oblong, 

 obtuse, the midvein greenish, the margins scarious; 

 bristles 2-4, shorter than the achene, fugacious or 

 wanting; achene obovoid, obtusely 3-angled, yellow- 

 ish-brown, papillose; stamens 3; style 3-cleft; tubercle 

 conic, short, acute. 



In wet soil, Cape Breton Island to Ontario and Mani 

 toba, south to Florida and Texas. The achenes are more 

 or less persistent on the rachis of the spikelet after tin 

 fall of the scales. May-July. 



59S-) 



20. Eleocharis acuminata (Muhl.) Nees. 



(Fig. 596.) 



Plat-stemmed spike-nub. 



Scirpus acumi not H a Muhl. < 



Eleocharis comprfssa Sulliv. Am Journ So 4) 50. 184* 



Eleocharis acuminata Nets, I.innara 



Perennial by stout rootstocks, similar to the pre- 

 ceding species but stouter, culms flattened, striate. 

 slender but rather stiff, tufted, 8'-a tall, t'pper 

 sheath truncate, sometimes slightly i -toothed; pike- 

 let ovoid or oblong, obtuse, thicker than the cola, 

 many-flowered, 3"-6" long; scales oblong or ovate- 

 lanceolate, acute or the lower obtusish, purple-brown 

 with a greenish midvein and hyaline white margin, 

 deciduous; bristles 1-5, shorter than or equalling the 

 achene, fugacious, or wanting; stamen* 3; sty k 3 -cleft. 

 exserted; achene obovoid, very obtusely 3-anjclnl, 

 light yellowish brown, papillose, much longer than 

 the depressed-conic acute tubercle. 



In wet soil. Antu-<n t< M.nm. k. 

 Louisiana and Missouri. Achenes 

 rachis as in E. tennis. Junc-Aug. 



21. Eleocharis intermedia (Muhl.) Schultes. Matted Spike-nu.1 ; 



to Georgia, 



nt on the 



Scirpus intermedius Muhl. Gram. 31. 1817. 

 Eleocharis intermedia Schultes, Mant. 2: 91. 



1824. 



Annual, roots fibrous, culms filiform, densely 

 tufted, diffusely reclining or ascending, usually 

 -matted, grooved, 4 / -i2 / long. Upper sheath ob- 

 liquely truncate, toothed on one side ; spikelet 

 ovoid- oblong, acute, 8-2o-flowered, thicker than 

 the culm; scales oblong-lanceolate, obtuse or the 

 upper subacute, light purple-brown with a green 

 midvein, tardily deciduous or the lower one per- 

 sistent; bristles persistent, downwardly barbed, 

 longer than the achene and tubercle; stamens 3; 

 style 3-cleft; achene 3-angled, obovoid, light brown, 

 finely reticulated; tubercle conic-subulate, very 

 acute, slightly constricted at the base, one-fourth 

 to one-half as long as the achene. 



In marshes, Ontario to Minnesota, south to New 

 Jersey, Ohio, Illinois and Iowa. July-Sept. 



17 





