HKMICARPHA CYPERACE^ 693 



ELKOCHARIS 



inches high, tufted, with reddish-brown basal sheaths : leaves filiform, 

 shorter than the stem : principal involucral bract continuous with the 

 stem, 5-8 lines long, the others shorter: spikelets greenish, broadly ovate: 

 scales with broadly ovate base and long acuminate spreading tips, twice 

 as long as the nutlet: hyaline scale truncate or erosely toothed, not ad- 

 herent to the nutlet. In wet grounds, base of Mount Adams Washington 

 to California. 



H. intermedia Piper Fl. Palouse Reg. 36. Stems numerous, tufted, 

 2-4 inches high : leaves narrow, involute, the recurved blades 6-18 lines 

 long : spikelets ovoid, obtuse, 1-2 lines long : involucral bracts usually 3, 

 the uppermost 6-18 lines long, the others much shorter : scales %-\ line 

 long, broadly obovate, the abruptly acuminate somewhat spreading or re- 

 curved apex as long as the body: hyaline scale triangular-ovate, not ad- 

 herent to the nutlet, which is oblong-ovate or obovate, about % line long, 

 with a short beak. Margins of ponds along the Columbia and Snake rivers, 

 Oregon and Washington. 



6 ELEOCHARIS R. Br. Prodr. Fl. Nov. Hoi. i, 224. (1810.) 



Annual or perennial herbs with simple triangular, quadrangu- 

 lar, terete, flattened or grooved stems, the leaves reduced to sheaths, 

 or the lowest rarely leaf-bearing, and small flowers in dense sol- 

 itary terminal spikes without an involucre. Scales concave, 

 spirally imbricated all around. Perianth of 1-12 bristles, usually 

 retrorsely barbed, wanting in some species. Stamens 2 or 3. 

 Style 2-cleft, the base persistent and forming a tubercle on the 

 summit of the more or less 3-angled achene. 



E. oyata R. & S. Syst. ii, 152. Glabrous annual with fibrous roots: 

 stems tufted, slender or filiform, rather deep green, nearly terete, mostly 

 erect, 2-16 inches high : spike ovoid or oblong, obtuse,* many-flowered, 

 2-5 lines long, 1-1 K lines in diameter: scales thin, oblong-orbicular, very 

 obtuse, brown with green midrib and scarious margins : bristles 6-8, de- 

 ciduous, usually longer than the achene : stamens 2 or 3 : style 2- or 3-cleft : 

 achene pale brown, shining lenticular, obovate-oblong, smooth, % line 

 long or more: tubercle deltoid, acute, compressed, scarcely constricted at 

 base, about % as long as the achene and narrower. In wet soil, Oregon to 

 Brit. Columbia, New Brunswick and Florida : also Europe. 



E. palustris R. & S. 1. c. 151. Perennial by horizontal often densely 

 matted rootstocks: stems stout, terete or somewhat compressed, striate, 

 1-5 feet high : basal sheaths brown, rarely bearing a short blade, the up- 

 per obliquely truncate: spike pvoid-cylindric, 4-12 lines long, 1)^-2 lines 

 in diameter, many-flowered, thicker than the stem : scales ovate-oblong or 

 ovate-lanceolate, purplish brown with scarious margins and green midrib, 

 or pale green all over: bristles usually 4, slender, longer than the achene 

 and tubercle, sometimes wanting: stamens 2 or 3: style 2- or 3-cleft: 

 achene lenticular, smooth, yellow, % line long: tubercle conic-triangular, 

 constricted at the base, flattened, J^-K as l n g as the achene. In ponds 

 and moist meadows, Alaska to California and across the continent : also in 

 Europe and Asia. 



Var. glaucescens Gray Man. ed. 5, 558. stems slender or nearly 

 filiform, 8-18 inches high : spikes oblong, 2-5 lines long: achenes smaller: 

 tubercle narrower. In wet meadows and marshes, range nearly of the 

 type in North America. 



E. acicularis R. & S. 1. c 354. Perennial by filiform stolons or root" 

 stocks: stems tufted, filiform or seUceous, obscurely 4-angled and grooved' 

 weak, erect or reclining, 1-8 inches leng: sheaths truncate: spikes com 



