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 redbrown or brown; sheaths of proximal leaves glabrous, fronts with indistinct spots, veinless, apex U-shaped; blades usually amphistomic, 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 redbrown 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"
biconvex +
not constricted +
papillose +
Lisa A. Standley +, Jacques Cayouette +  and Leo Bruederle +
Wahlenberg +
shortened +
not +  and fibrous +
tapering +  and rounded +
bidentate +  and emarginate +
papillose +
m--shaped +  and v--shaped +
0mm;20mm +
glumaceous +  and foliaceous +
2-ranked +  and arranged +
ascending +  and appressed +
scale-like +  and leaflike +
parallel +  and divergent +
terete +, rolled +  and plicate +
redbrown +  and brown +
round +  and trigonous +
20 cm200 mm <br />0.2 m <br /> (150 cm1,500 mm <br />1.5 m <br />) +
prophyllate +, subsessile +, pedunculate +  and staminate +
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 +
open +, pistillate +  and staminate +
hypogynous +  and subtending +
biconvex +  and trigonous +
multi-ranked +, 2-ranked +, 3-ranked +  and alternate +
basal +  and cauline +
with (1-)3-6(-30) bristles and/or scales +
2-3(-4)-carpellate +
3 (?) +  and 1 (?) +
short-sheathing +, sheathless +  and leaflike +
Kongl. Vetensk. Acad. Nya Handl. +
adventitious +
redbrown +  and purple-brown +
basal +  and proximal +
2-keeled +
ladder-fibrillose +  and veined +
cylindric +
W2 +, W1 +  and Illustrated +
staminate +  and pistillate +
indistinct +
1 (?) +  and 3 (?) +
septate +, hollow +  and solid +
compressed +, terete +  and trigonous +
papillate +
deciduous +
2-3(-4)-fid +
Carex sect. Acutae +, Carex sect. Cryptocarpae +  and Carex sect. Temnemis +
Carex aquatilis +
Carex sect. Phacocystis +
species +
, +  and staminate +
plant +  and not cespitose +