Carex laeviconica Dewey

Stems stout, 5–12 dm, arising singly or few together from long rhizomes, aphyllopodic, the lower sheaths soon breaking and becoming strongly fibrillose; lvs glabrous, the main ones 3–6 mm wide, usually evidently cross-septate; staminate spikes ca 3, distal; pistillate spikes 2–4, very remote, cylindric, 3–7 cm, densely fld, erect, sessile or short-peduncled, sometimes staminate at the top; bracts lf-like but scarcely or not at all sheathing, equaling or surpassing the infl; pistillate scales thin, hyaline or pale brown, the body usually much shorter than the perigynium, either acuminate or obtuse with the green midvein prolonged into an awn nearly or quite equaling the perigynium; perigynia 5.5–9 mm, broadly ovoid, conspicuously many-nerved, tapering into a slender, minutely scabrous beak with nearly straight, moderately divergent, scabrous teeth 1–2.2 mm; achene trigonous, loosely enveloped, with a persistent, straight, slender style; 2n=110. Swales and borders of ponds; Ill. and Mo. to Sask.