Scrabrous Black Sedge

Carex atratiformis Britton, Bull. Torrey Club 22: 222. 1895
Carex ovata Rudge, Trans. Linn. Soc. 7: 96. pi. 9. f. /. 1804. (Type from Newfoundland.) Not
C. ovala Burm. /. 1768. Carex atrata var. ovata Boott, 111. Carex 114. pi. 362. 1862. (Based on C. ovata Rudge.) Carex atrata subsp. atratiformis "Britton" Kiikenth. in Engler, Pflanzenreich 4 20 : 399. 1909.
(Based on C. atratiformis Britton.) X Carex quirponensis Fernald (C. atratiformis X Halleri), Rhodora 28: 164. 1926. (Type from
Quirpon Island, Newfoundland.)
Cespitose, the rootstocks slender, short, the clumps medium-sized, the culms slender, 2-9 dm. high, much exceeding the leaves, sharply triangular, more or less roughened above, phyllopodic, purplish-red-tinged at base, the dried-up leaves of the previous year conspicuous; leaves with well-developed blades 6-15 to a fertile culm, clustered above the base, not septatenodulose, the blades flat with revolute margins, glaucous-green, thin but firm, erect or ascending, 1-2.5 dm. long, 2.5-5 mm. wide, short-attenuate, much roughened towards the apex, the sheaths white-hyaline ventrally, often yellowish-tinged, concave at mouth, the ligule wider than long; spikes 3-6, the lateral pistillate with a very few basal staminate flowers, the terminal gynaecandrous, approximate or little separate, the lower nodding on slender, rough peduncles 1-2 times the length of the spikes, the upper more erect on shorter peduncles, the spikes narrowly oblong, 1-2.5 cm. long, 4-6 mm. wide, or the terminal one slightly wider, densely flowered, the 10-30 closely appressed perigynia ascending in several to many rows; lowest bract leaflet-like, mostly shorter than the culm, scarcely sheathing, slightly darkened at base ; upper bracts much reduced; scales ovate, obovate or oblong-lanceolate, acute to shortcuspidate, dull, not shining, dark-reddish-brown to brownish-black with nearly obsolete midrib and minutely hyaline margins, the pistillate about as wide as and slightly longer than the perigynium; perigynia ovoid to orbicular-ovoid, flattened-oval in cross-section, 2-edged, distended over achene, slightly inflated, 2.5-3 mm. long, 1.5-1.75 mm. wide, 2-ribbed (the marginal), nerveless or few-nerved, membranaceous, granular, puncticulate, purplish-brown, or straw-colored below, obscurely very short-stipitate, rounded at base, round-tapering and abruptly short-beaked at apex, the beak apiculate, 0.5 mm. long, shallowly bidentate; achenes small, obovoid, 1.5-1.75 mm. long, 0.75-1 mm. wide, loosely enveloped in lower part of perigynium, triangular with lightly concave sides, nearly sessile, silvery-black and shining, strongly granular, apiculate, jointed with the slender style; stigmas 3, slender, short.
Type locality (of C. ovata Rudge, on which C. atratiformis is based): "Habitat in Newfoundland."
Distribution: Sunny banks and meadows along streams in calcareous districts, Labrador and Newfoundland to Yukon, and southward to Maine, Michigan, and Alberta. (Specimens examined from Labrador, Newfoundland, Quebec, New Brunswick, Maine, New Hampshire, Vermont, Michigan, Alberta.)