CYPERACEAE. 



VOL. I. 



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



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

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

 Eleocharis nitida Fernald, Rhodora i : 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 i" 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. 1817. 



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



Eleocharis acuminata Nees, Linnaea 9: 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 . tenuis. June-Aug. 



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



Scirpus intermedius 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, 8-2o-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 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. 



