Shoreline Sedge

Carex hyalinolepis is abundant in the Mississippi lowlands and often dominant in the understory of open, wet floodplain forests and bottomland meadows. It is a rapid invader of ditches and other disturbed areas. Sometimes extensive stands are seen without fertile culms.

Occasionally, Carex hyalinolepis hybridizes with C. pellita (= C. ×subimpressa Clokey, according to A. A. Reznicek and P. M. Catling 1986), and rarely with C. lacustris. Carex ×subimpressa is sufficiently frequent that it has been treated as a species in some floras. It can form large colonies in suitable sites.

Plants colonial; rhizomes long-creeping. Culms central, coarse, trigonous, 40–110 cm, smooth. Leaves: basal sheaths pale green to brownish or pale red tinged, base with marescent remains of previous year’s leaves; longest ligules 2–10(–12) mm, less than 2 times longer than wide; blades glaucous, flat to V-shaped, (4–)5.5–13 mm wide, glabrous. Inflorescences 15–50 cm; proximal 2–4 spikes pistillate, ascending to arching; distal spikes erect; terminal 3–6 spikes staminate. Pistillate scales lanceolate to ovate, apex obtuse to acute, glabrous, awn 0.9–8.5 mm, scabrous. Perigynia ascending, obscurely 10–15-veined, veins somewhat impressed, narrowly ovoid, (4.5–)5.5–7.7 × 1.6–3 mm, glabrous; beak obscure, 0.9–1.7 mm, bidentulate, teeth straight, 0.4–0.8 mm.

Ont.; Ark., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Md., Mich., Miss., Mo., Nebr., N.C., Ohio, Okla., Pa., S.C., Tex., Va.

Fruiting Apr–Jul.

Swamp forests, river bottoms, shores of streams, ponds and lakes, wet meadows, often in clay soils, seasonally moist sites; 0–400m.

Carex hyalinolepis Steud. Syn. Cyp. 235. 1855
Carex lacustris var. laxiflora Dewey, Am. Jour. Sci. II. 35: 60. 1863. (Type from Nebraska.) Carex riparia var. impressa S. H. Wright, Bull. Torrey Club 9: 151. 1882. (Type from Dallas,
Texas.) Carex impressa (S. H. Wright) Mackenzie, Bull. Torrey Club 37: 236. 1910. (Based on C. riparia
var. impressa S. H. Wright.)
Cespitose and stoloniferous, the stolons long, horizontal, rather slender, scaly, the culms 5-10 dm. high, 6-13 mm. thick at base, stiff, erect, usually exceeded by the leaves, phyllopodic, sharply triangular, from smooth to more or less roughened above, light-brownish and little if at all purplish-tinged, the basal sheaths of the fertile culms not breaking and becoming filamentose; sterile shoots aphyllopodic, elongate, their basal sheaths breaking and becoming filamentose; leaves with well-developed blades usually 6-12 to a fertile culm, largely bunched toward the base, very conspicuously septate-nodulose, the blades glaucous-green, firm, fiat above with somewhat revolute margins and strongly channeled toward base, 1.5-4 dm. long, 4-15 mm. wide, long-attenuate, strongly roughened on the margins at least toward the apex, the two mid-lateral nerves inconspicuous above, the conspicuous septa (in the larger leaves) almost entirely between them and the margin, the sheaths very thin ventrally and slightly yellowish-brown-tinged, thickened at mouth, occasionally breaking and becoming filamentose, the ligule short, much wider than long; staminate spikes 2-4, erect, scattered, narrowly linear, 1-4 cm. long, 3-7 mm. wide, the upper peduncled, the others sessile or nearly so, the scales numerous, closely appressed, oblong-obovate, tapering above, acute to aristate, purplish-red with lighter center and hyaline margins, or becoming straw-colored in age; pistillate spikt usually strongly separate, erect, sessile or short-peduncled (the peduncle nearly smooth), oblong-cylindric, 1-7.5 cm. long, 10-14 mm. wide, closely flowered above or somewhat loosely at base, the 50-150 perigynia spreading-ascending or appressed-ascending in several to manyrows; lowest bract leaf -like, exceeding culm, shortto long-sheathing, thickened at mouth, the upper reduced; scales ovate, purplish-brown with lighter 3-nerved center and hyaline margins, the lower aristate and often exceeding the perigynia, the others gradually shorter, the upper acute and but half as long as the perigynia; perigynia lanceolate-ovoid, 6 mm. long, 2.5 mm. wide, flattened-suborbicular in cross-section, little inflated, coriaceous, glabrous, not papillate, dull-green, finely many-impressed-nerved, rounded and oblique at base, sessile or substipitate, tapering to a short, smooth, flattened, bidentate beak 1 mm. long, the teeth smooth, short, erect or nearly so, 0.5 mm. long; achenes oval-obovoid, 2-2.5 mm. long, 1.25-1.5 mm. wide, triangular with blunt angles and slightly concave sides, rather loosely enveloped, sessile, continuous with the slender, persistent, flexuous style; stigmas 3, slender, blackish, rather stout.
Type locality: New Orleans, Louisiana {Drummond 422).
Distribution: Open swamps and wet swales, in calcareous and non-acid soils, Florida to Texas, and northward to southern New Jersey and southeastern Pennsylvania along the coast and to southwestern Ontario and Nebraska in the Mississippi Valley. (Specimens examined from New Jersey, Pennsylvania, North Carolina, South Carolina, Georgia, Alabama, Florida, Louisiana, Texas, Oklahoma, Arkansas, Tennessee, Kansas, Nebraska, Missouri, Iowa, Illinois, Indiana, Ohio, Michigan, southwestern Ontario.)

Carex hyalinolepis is a tussock-forming species of perennial sedge in the family Cyperaceae. It is native to southern parts of North America from Ontario in the north to Texas in the south.