3** 



CYPERACEAE. 



Vol. I. 



22. Eleocharis tenuis (Willd.) Schultes. Slender Spike-rush. Fig. 779. 



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

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

 Eleocharis nitida Fernald, Rhodora 1 : 76. 1906. 



Perennial by rootstocks, culms tufted, filiform, 

 mostly erect, 4-angled with concave sides, 8'-i6' tall. 

 Upper sheath obliquely truncate, toothed on one side; 

 spikelet narrowly oblong, mostly acute, many-flowered, 

 thicker than the culm, 3"-$" long, about 1" 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, yellowish-brown, papillose; stamens 

 3; style 3-cleft; tubercle conic, short, acute. 



In wet soil, Cape Breton Island to Ontario and Manitoba, 

 south to Florida-and Texas. The achenes are more or less 

 persistent on the rachis of the spikelet after the fall of the 

 scales. Poverty-grass. Kill-cow. May-July. 



23. Eleocharis acuminata (Muhl.) Nees. Flat-stemmed Spike-rush. Fig. 780. 



Scirpus acuminatus Muhl. Gram. 27. 181 7. 



Eleocharis compressa Sulliv. Am. Journ. Sci. 42: 50. 1842. 



Eleocharis acuminata Nees, Linnaea g: 294. 1835. 



Perennial by stout rootstocks, similar to the pre- 

 ceding species, but stouter, culms flattened, striate, 

 slender but rather stiff, tufted, 8-2° tall. Upper sheath 

 truncate, sometimes slightly i-toothed; spikelet ovoid 

 or oblong, obtuse, thicker than the culm, many-flowered, 

 3"-6" long; scales oblong or ovate-lanceolate, acute or 

 the lower obtusish, purple-brown with a greenish mid- 

 vein and hyaline white margins, deciduous; bristles 1-5, 

 shorter than or equalling the achene, fugacious, or 

 wanting; stamens 3; style 3-cleft, exserted; achene 

 obovoid, very obtusely 3-angled, light yellowish brown, 

 papillose, much longer than the depressed-conic acute 

 tubercle. 



In wet soil, Anticosti to Manitoba, Washington, Georgia, 

 Louisiana, Missouri and Nebraska. Achenes persistent .on 

 the rachis as in E. tenuis. June-Aug. 



24. Eleocharis intermedia (Muhl.) Schultes. Matted Spike-rush. Fig. 781. 



Scirpus intermedins Muhl. Gram. 31. 1817. 

 Eleocharis intermedia Schultes. Mant. 2: 91. 1824. 

 E. intermedia Habereri Fernald, Rhodora 8: 130. 1906. 

 E. Macounii Fernald, Proc. Am. Acad. 34: 497. 1899. 



Annual, roots fibrous, culms filiform, densely tufted, 

 reclining or ascending, grooved, 4'-i2' long. Upper 

 sheath obliquely truncate, toothed on one side; spikelet 

 ovoid-oblong, acute, 8-20-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 persistent; bristles 

 persistent, downwardly barbed, longer than the achene 

 and tubercle, sometimes wanting; stamens '3; style 

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

 reticulated ; tubercle conic to conic-subulate, very acute, 

 one-fourth to one-half as long as the achene. 



In marshes, Quebec to Minnesota, south to New Jersey, 

 Ohio, Illinois and Iowa. July-Sept. 



