75. Carex hyalinolepis Steud.

Pl. 51 a–e; Map 191

C. lacustris Willd. var. laxiflora Dewey

Vegetative stems (actually false stems composed nearly entirely of a series of overlapping leaf sheaths) relatively short (10–25 cm), the lowermost leaves reduced to nearly bladeless sheaths. Flowering stems 40–120 cm long, mostly longer than the leaves, the bases usually somewhat obscured by the brown, partially disintegrated remains of the previous season’s basal leaf sheaths, light brown or sometimes lightly reddish tinged. Leaves of flowering stems all with well-developed blades. Leaf blades 10–50 cm long, 6–15 mm wide, flat with somewhat recurved margins toward the tip, channeled near the base, light green, often somewhat glaucous. Leaf sheaths with the ligule wider than long to about as long as wide and U-shaped, the lowermost sheaths light brown or less commonly somewhat reddish tinged, the ventral side usually not becoming dissected into a ladderlike pattern of fibers. Staminate spikes 2–4 per flowering stem, 10–50 mm long, the scales 4–11 mm long, narrowly oblong-elliptic, the tip tapered to a point or short awn, purplish red with a lighter center and white margins, often becoming entirely straw-colored at maturity. Pistillate spikes 2–4, 10–90 mm long, 10–14 mm wide, narrowly oblong in outline, the scales 4–11 mm long, ovate to narrowly ovate, the tip tapered to a point or short awn, brown or purplish red with a lighter center and white margins. Perigynia 5–8 mm long, narrowly ovate in outline, the tip gradually tapered to the beak, the surface nerveless to more commonly finely nerved with impressed or slightly raised nerves, dull green, glabrous. Styles persistent, somewhat bent or contorted near the base, forming a hard, bony beak similar in texture to the main body of the fruit. Fruits with the main body 2.0–2.5 mm long. April–July.

Scattered nearly throughout the state, principally in the floodplains of river systems, but absent from portions of the Ozarks and uncommon in the northernmost portions of the Glaciated Plains (southeastern U.S. west to Texas, north to New Jersey and Kansas, and extending northward through Illinois and Michigan to southern Canada). Occupies a variety of wetlands, including swamps, sloughs, bottomland prairies, marshes, fens, openings of bottomland forests, margins of rivers and lakes, and rarely along the edges of sinkhole ponds; also in ditches and wet, disturbed areas.

In Missouri, C. hyalinolepis is far more common and variable, morphologically, than C. lacustris. The two species can be difficult to distinguish, and the characters that separate them most easily are vegetative, rather than reproductive features. Occasional specimens of C. hyalinolepis can have the lower leaf sheaths reddish tinged and somewhat dissected into a ladderlike pattern of fibers ventrally, but they can be distinguished by their short ligules and relatively short vegetative stems. The two species are known to hybridize rarely where they grow together, but such hybrids have yet to be reported from Missouri.

For discussion of the hybrid with C. pellita, see the treatment of that species.