17. Carex laxiculmis Schwein.

Pl. 34 j–m; Map 130

C. laxiculmis var. copulata (L.H. Bailey) Fernald

C. ×copulata (L.H. Bailey) Mack.

Plants without noticeable rhizomes, forming dense tufts. Vegetative stems with the leaves slightly wider than those of the flowering stems. Flowering stems 15–60 cm long, weak, erect to more commonly spreading, white to light brown at the base. Leaves shorter than to longer than the stems. Leaf blades 10–35 cm long (except on bladeless, basal sheaths), 3–15 mm wide, thin, green to grayish green, sometimes somewhat glaucous, the margins and veins minutely roughened or toothed, flat. Leaf sheaths with the tip deeply concave, the lowermost sheath bases white to light brown, sometimes with scattered, small, reddish purple spots. Spikes 3–5 per stem, the bracts leaflike, shorter than to longer than the inflorescence. Staminate spike 8–22 mm long, sessile to long-stalked, not hidden by the bracts of the pistillate spikes. Pistillate spikes 6–20 mm long, 4–5 mm wide, short- to long-stalked, ascending to spreading or drooping, with 4–9 perigynia, the lowermost 1 or 2(3) scales empty or with staminate flowers. Scales of the staminate spikes 3.5–4.5 mm long, yellowish white to white with a green or straw-colored midrib and sometimes light brown or faintly reddish purple margins. Pistillate scales (including the basal, sterile or staminate-flowered ones) 2.5–3.2 mm long, ovate to elliptic, the tip sharply pointed and usually awned, yellowish white to white or tan with a green or straw-colored midrib and sometimes light brown or faintly reddish purple margins. Perigynia 2.5–4.0 mm long, elliptic to ovate in outline, tapered abruptly to a short, slightly bent beak at the tip. Fruits 2.2–3.2 mm long. 2n=44, 46. May–June.

Uncommon in the southeastern quarter of the state, mostly in the Ozark Division (northeastern U.S. and adjacent Canada west to Iowa and Arkansas; possibly also in northern Florida). Mesic upland forests, particularly on rich, north-facing slopes, often on calcareous substrates.