Hairy Sedge

Carex lacustris Wilid. Sp. PL 4: 306. 1805
" Carex riparia Curtis" Muhl. Descr. Gram. 259. 1817.
Anilhista lacustris Raf. Good Book 26. 1840. (Based on Carex lacustris Willd.)
Carex riparia var. inferior Peck, Ann. Rep. N. Y. State Mus. 49: 43. 1897. (Type from Karner,
New York.) Carex riparia var. lacustris Kiikenth. in Engler, Pflanzenreich 4 20 : 736. 1909. (Based on C. lacustris
Willd.)
Cespitose and stoloniferous, the stolons long, horizontal, rather slender, scaly, the culms 6-13 dm. high, stout, 8-15 mm. thick at base, stiff, erect, usually exceeding the leaves, aphyllopodic, sharply triangular and rough above, strongly purple-tinged at base, the basal sheaths breaking and becoming conspicuously filamentose ventrally; sterile shoots elongate, the leaves clustered at apex; leaves with well-developed blades 3-5 to a fertile culm, not clustered at base, septate-nodulose, the blades glaucous-green, firm, flat with revolute margins, 2-5 dm. long, 5-15 mm. wide, the two midlateral nerves conspicuous above and the rather inconspicuous septa evenly distributed, attenuate, strongly roughened on the margins, the sheaths slightly yellowish-brown-tinged and thinnish at mouth, breaking and becoming filamentose, the ligule very conspicuous, much longer than wide; staminate spikes 2 or 3, linear, the lateral sessile, the terminal peduncled, 4-7 cm. long, 4-5 mm. wide, the scales oblong-obovate, obtuse, retuse or emarginate, mucronate or abruptly awned, reddish-purple with lighter center and hyaline margins; pistillate spikes 2 or 3, strongly separate, erect, sessile, or the lower short-peduncled (the peduncles slightly rough), oblong-cylindric, 2.5-10 cm. long, 10-14 mm. wide, closely flowered above or somewhat loosely at base, the 50-150 perigynia spreading-ascending in several to many rows; lowest bract leaf-like, usually exceeding culm, sheathless or neai not thickened at mouth, the upper reduced; scales ovate, awned or acuminate, purplish with 3-nerved green center and narrow hyaline margins, narrower than and half us long as the perigynia; perigynia oblong-ovoid, 5.5-7 mm. long, 2 mm. wide, flattened suborbicular in crosssection, little inflated, coriaceous, glabrous, not papillate, olive-green, strongly many-n< srved, rounded at base, sessile or very nearly so, tapering at apex into a short, smooth, flattened, bidentate beak 1 mm. long, the teeth smooth, short, erect, 0.5 mm. long; achenes broadly ovalobovoid, 2.5 mm. long, 1.5 mm. wide, triangular with blunt angles and slightly concavi rather loosely enveloped, sessile, continuous with the slender, persistent, abruptly bent or flexuous style; stigmas 3, slender, blackish, rather short.
Type locality: "Habitat in Pensylvania."
Distribution: Swamps in calcareous districts, Quebec and Nova Scotia to Manitoba, and southward to District of Columbia and Iowa. (Specimens examined from Quebec. New Brunswick, Nova Scotia, Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Pennsylvania, Delaware, District of Columbia, Ontario, Ohio, Michigan, Indiana, Wisconsin, Illinois, Minnesota, Iowa.)