Plants not cespitose. Culms 20–150 cm. Leaves: basal sheaths red-brown or brown; sheaths of proximal leaves glabrous, fronts with indistinct spots, veinless, apex U-shaped; blades usually amphi-stomic, papillose on both surfaces. Inflorescences: proximal bract longer than inflorescence. Spikes: erect; proximal 2–6 spikes pistillate; terminal (1–)2–4 spikes staminate. Pistillate scales red-brown to purple-brown, apex obtuse or acute, awnless. Perigynia ascending, veinless, somewhat flattened, loosely enclosing achenes, ellipsoid or obovoid, dull, apex obtuse or acute, papillose. Achenes not constricted, glossy. 2n = 72–80.
Distribution
North AmericaEurope.
Discussion
Carex aquatilis is circumboreal and variable; four extensively intergrading varieties are recognized in North America. The species is distinguished by amphistomic (epistomic in var. dives) papillose leaves, glabrous sheaths with a concave apex, perigynia that lack veins and are usually brown-spotted on the proximal half, and have glossy achenes.
