Carex subimpressa Clokey, Rhodora 21: 84. 1919
Carex lanuginosa X impressa Clokey, Torreya 16: 199. 1916. (Type from Macon County, Illinois.)
Loosely cespitose and stoloniferous, forming beds, the stolons long, horizontal, rather slender, tough, scaly, the culms 3-6 dm. high, erect, shorter than the leaves, aphyllopodic, sharply triangular, more or less roughened above, purplish-tinged at base; sterile shoots conspicuous, elongate, the leaves largely bunched near the top ; leaves with well-developed blades 3-5 to a fertile culm, not clustered at base, strongly septate-nodulose, the blades flat or somewhat channeled toward base, the margins somewhat revolute, thin but firm, dull-green, 1.5-4 dm. long, 3-6 mm. wide, long-attenuate, roughened toward apex; the sheaths tight, glabrous, deeply concave and dull-brownish at mouth, the lower at least breaking and becoming filamentose, the ligule wider than long; staminate spikes usually 3, contiguous or somewhat separated, narrowly linear, slender, 2.5-5 cm. long, 3 mm. wide, the scales oblanceolate, short-awned to acuminate, not ciliate, dull-reddish with lighter center and narrow dull-white margins, or in age straw-colored; pistillate spikes usually 2, separated, erect, short-peduncled, or the upper sessile or nearly so, oblong-cylindric, 2.5-7.5 cm. long, 8-12 mm. wide, closely flowered, or sometimes more loosely toward base, the perigynia 25-75, spreading-ascending in several to many rows; bracts leaf -like, the lowest short-sheathing, exceeding culm; scales lanceolate to ovate-lanceolate, rough-awned, the center green, strongly 3-nerved, the margins dull-hyaline, more or less strongly purplish-tinged, narrower and usually shorter than the perigynia; perigynia ovoid, 5 mm. long, 2.5 mm. wide, suborbicular in cross-section, somewhat inflated, coriaceous, many-ribbed, the ribs mostly hidden by the short dense pubescence, dull-green or grayish-green, rounded at base, sessile, contracted into a slender, somewhat flattened, bidentate beak about half as long as the body, the teeth 0.5 mm. long, slender, stiff, ascending, hispidulous within; achenes orbicular-obovoid, 1.75 mm. long, 1.5 mm. wide, triangular with concave sides below and prominent angles, loosely enveloped in lower half of perigynium-body, yellowish, substipitate, abruptly contracted into and continuous with the long, slender, strongly flexuous style; stigmas 3, slender, dark-colored, rather long.
Type locality (of C. lanuginosa X impressa, on which C. subimpressa is based): Cowford bridge, Macon County, Illinois (Clokey 2338).
Distribution: Swampy open woodlands, Indiana and Illinois. (Specimens examined from Indiana and Illinois.)

Carex subimpressa là một loài thực vật có hoa trong họ Cói. Loài này được Clokey mô tả khoa học đầu tiên năm 1919.