252 



CYPERACEAE. 



Eleocharis palustris glaucescens (Willd.) A. Gray, Man. Ed. 5, 558. 1867. 

 Scirpus glaucescens Willd. Enum. 76. 1809. 



Culms slender or nearly filiform, 8'-i8' tall; spikelet oblong, 2" -5" long; achene smaller; 

 tubercle narrower. In wet meadows and marshes, range nearly of the type m North America. 

 Perhaps a distinct species. 



The so-called variety calva is a form without bristles. 



Eleocharis palustris Watsoni Clarke, Britten's Journ. Bot. 25: 268. 1887. 

 Eleocharis Watsoni Bab. Ann. Nat. Hist. (II.) 5: 10. 1852. 



Culms stout, 6'-io' tall; spike ovoid; scales dark purple-brown. Labrador and Prince Edward 

 Island to Hudson Bay. 



ii. Eleocharis acicularis (I,.) R. & S. Needle Spike-rush. (Fig. 587.) 



Scirpus acicularis I,. Sp. PI. 48. 1753. 

 Eleocharis acicularis R. &S. Syst. 2: 154. 



1817. 



Perennial by filiform stolons or rootstocks, 

 culms tufted, finely filiform or setaceous, 

 obscurely 4-angled and grooved, weak, erect 

 or reclining, 2 / -8 / long. Sheaths truncate; 

 spikelet compressed, narrowly ovate or lin- 

 ear-oblong, acute, broader than the culm, 3- 

 lo-flowered, ij^"-^" long, YZ" wide; scales 

 oblong, obtuse or the upper subacute, thin, 

 pale green, usually with a narrow brown 

 band on each side of the midvein, deciduous, 

 many of them commonly sterile; bristles 3- 

 4, fragile, fugacious, shorter than the achene; 

 stamens 3; style 3-cleft; achene obovoid- 

 oblong, pale, obscurely 3-angled with a rib 

 on each angle and 6-9 lower intermediate 

 ribs connected by fine ridges; tubercle conic, 

 acute, one-fourth as long as the achene. 



In wet soil, throughout North America, ex- 

 cept the extreme north. Also in Europe and 

 Asia. Sometimes entirely sterile. July-Sept. 



12. Eleocharis Wolfii A. Gray. Wolf's 

 Spike-rush. (Fig. 588.) 



Scirpus Wolfii A. Gray, Proc. Am. Acad. 10: 77. 1874. 



Eleocharis Wolfii A. Gray; Britton, Journ. N. Y. 

 Micros. Soc. 5: 105. 1889. 



Perennial by short rootstocks, culms very slen- 

 der, erect, flattened and 2-edged, S'-iS' tall. Upper 

 sheath oblique, scarious, hyaline-tipped; spikelet 

 oblong or ovoid-oblong, terete, acute, thicker than 

 the culm, 2 // ~3 // long, nearly \" in diameter; 

 scales ovate, obtuse or the upper acute, thin, pale 

 green with purplish-brown bands, tardily decidu- 

 ous; bristles none (or perhaps early deciduous); 

 style 3-cleft; achene obovoid, obscurely 3-angled, 

 longitudinally 9-ribbed, the ribs transversely con- 

 nected by. minute ridges; tubercle depressed-conic, 

 much shorter than the achene. 



In wet meadows, Illinois and Iowa. June-Aug. 



