220 CYPERACE/E. Eriopkorum. 



A small genus, of only 6 or 8 species, peculiar to northern temperate and arctic regions. Nearly 

 all are common to North America and the Old World. 



1. E. gracile, Koch. Stems very slender, a foot or two high, terete or slightly 

 triangular, with one or more erect very narrow triangular leaves : involucre of 2 or 

 3 erect brownish ovate-lanceolate bracts or the lowest somewhat foliaceous : spike- 

 lets 2 to 5, on short tomentose-scabrous slightly nodding rays (usually a half-inch 

 long or less), oblong, 3 or 4 lines long ; scales ovate, obtuse, slate-colored or brownish : 

 nutlet linear-oblong, broadest above, 1^ lines long. Reichenb. Icon. Fl. Germ, viii, 

 t. 290. 



Swamps near Santa Rosa, Sonoma County (Biyclow) ; Big Trees (Hillebrand) ; Sierra County 

 (Lemmon) ; eastward in the northern border States and Canada, and also European. 



E. POLYSTACHYUM, Linn., has been collected in marshes near Mount Hood (Howell) and may 

 enter California. It is a stouter species, with mostly flat linear leaves and a more conspicuous 

 involucre ; spikelets more numerous and larger, upon longer nodding and usually smooth rays ; 

 nutlet broader. The most common species eastward and in Europe, under several forms. 



4. HEMICARPHA, Nees. 



Distinguished from Scirpus Isolepis by a minute hyaline scale at the base of the 

 flower on the side next to the rhachis of the spikelet. Hypogynous bristles none. 

 Stamen 1, anterior to the ovary and more or less lateral. Style 2-cleft. Nutlet 

 oblong-obovate, nearly terete. Low or dwarf setaceous annuals, with flattened 

 stems, somewhat leafy at base, bearing 1 to 3 small spikelets sessile in an involucrate 

 cluster. 



Besides the following American species there is another found at the Cape, of Good Hope and 

 in the East Indies, and perhaps one or two more. Boeckelcr refers the species all to Scirpus, con- 

 sidering the hypogynous scale as only a sterile filament or staminodium. Its constant position 

 next to the axis and its insertion below that of the stamen seem, however, to indicate the proba- 

 ble correctness of the view taken by Nees. 



1. H. subsquarrosa, Nees. Stems numerous, tufted, 1 to 6 inches high, 

 brown-sheathed at base, with 1 or 2 very short filiform leaves : principal involucral 

 bract continuous with the stem, often | to 1 inch long, the others much smaller or 

 none : spikelets 1 to 3, brownish, ovate, 1 to 1 1 lines long ; scales numerous, 

 cuueate-obovate, shortly acuminate and slightly spreading at the tip or erect, very 

 small, little exceeding the obtuse nutlet (\ of a line long). Fl. Bras. i. 61, t. 4, 

 tig. 1. Scirpus subsquarrosus, Muhl. /S. micranthus, Vahl ; Boeck. in Liiinsea, 

 xxxvi. 49. 



Valley of the Sacramento (Pickering) ; Arizona (Rofhrock] ; New Mexico, and eastward through 

 the Atlantic States ; also in Mexico and Brazil. The delicate scale above the ovary varies much 

 in form, often broadly cuneate-obovate and investing the ovary, somewhat adherent to the nutlet, 

 truncate or acutely Smoothed and faintly 3-nerved, or sometimes narrow and 2-cleft nearly to the 

 base, and sometimes apparently wholly wanting. 



2. H. OCCidentalis, Gray. Similar in habit, but the stems only an inch or 

 two high : spikelets greenish, broadly ovate, with spreading lanceolate long-acumi- 

 nate scales nearly a line long and twice longer than the nutlet : hyaline scale trun- 

 cate or erosely toothed, 2 - 4-nerved, shorter and not adherent to the nutlet. Proc. 

 Amer. Acad. vii. 391. 



Yosemite Valley (Bolander) ; foothills of the Sierra Nevada, Lemmon. 



5. ELEOCHABIS, R. Brown. SPIKE-RUSH. 



Flowers perfect, usually many, in a solitary naked spikelet terminating a leafless 

 stem ; scales closely imbricated all around the rhachis, rarely somewhat distichous 

 or 3-ranked, only 1 or 2 of the lower scales sometimes empty. Perianth of 3 to 9 

 (usually 6) short retrorsely barbed bristles, rarely none. Stamens mostly 3. Style 



