Carex aquatilis

Wahlenberg
Kongl. Vetensk. Acad. Nya Handl. 24: 165. 1803.
Illustrated
Treatment appears in FNA Volume 23. Treatment on page 397. Mentioned on page 380, 382, 383, 384, 385, 388, 389, 390, 394, 395.

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

V23 709-distribution-map.jpg

Alta., B.C., Man., N.B., N.S., N.W.T., Nunavut, Ont., P.E.I., Que., Sask., Yukon, Alaska, Ariz., Calif., Colo., Conn., Idaho, Ill., Ind., Iowa, Kans., Maine, Mass., Mich., Minn., Mo., Mont., N.Dak., N.J., N.Mex., N.Y., Nebr., Nev., Ohio, Oreg., Pa., S.Dak., Utah, Va., Vt., Wash., Wis., Wyo., Europe.

Discussion

Varieties 4 (4 in the flora).

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.

Selected References

None.

Key

1 Spikes pendent or the terminal erect; proximal peduncle to 11 cm; perigynia ellipsoid; beak purple-brown, 0.3–0.4 mm; culms scabrous on angles. Carex aquatilis var. dives
1 Spikes erect; proximal peduncle not more than 4 cm; perigynia usually obovoid; beak pale or purple-brown, not more than 0.2 mm; culms glabrous or scabrous on angles. > 2
2 Pistillate scales pale brown with narrow red-brown margins and broad pale midvein. Carex aquatilis var. substricta
2 Pistillate scales red- or purple-brown and narrow pale midvein. > 3
3 Perigynia pale brown; staminate spikes usually 2–4. Carex aquatilis var. aquatilis
3 Perigynia purple-brown on apical 1/2; staminate spikes usually 1–2. Carex aquatilis var. minor
... more about "Carex aquatilis"
Lisa A. Standley +, Jacques Cayouette +  and Leo Bruederle +
Wahlenberg +
Alta. +, B.C. +, Man. +, N.B. +, N.S. +, N.W.T. +, Nunavut +, Ont. +, P.E.I. +, Que. +, Sask. +, Yukon +, Alaska +, Ariz. +, Calif. +, Colo. +, Conn. +, Idaho +, Ill. +, Ind. +, Iowa +, Kans. +, Maine +, Mass. +, Mich. +, Minn. +, Mo. +, Mont. +, N.Dak. +, N.J. +, N.Mex. +, N.Y. +, Nebr. +, Nev. +, Ohio +, Oreg. +, Pa. +, S.Dak. +, Utah +, Va. +, Vt. +, Wash. +, Wis. +, Wyo. +  and Europe. +
Kongl. Vetensk. Acad. Nya Handl. +
W2 +, W1 +  and Illustrated +
Carex sect. Acutae +, Carex sect. Cryptocarpae +  and Carex sect. Temnemis +
Carex aquatilis +
Carex sect. Phacocystis +
species +