Carex nigra

(Linnaeus) Reichard

Fl. Moeno-Francof. 2: 96. 1778.

Common names: Carex noir
Basionym: Carex acuta var. nigra Linnaeus Sp. Pl. 2: 978. 1753
Synonyms: Carex ×aquanigra B. Boivin Carex nigra var. strictiformis (L. H. Bailey) Fernald Carex vulgaris var. strictiformis L. H. Bailey
Treatment appears in FNA Volume 23. Treatment on page 394. Mentioned on page 379, 381, 382, 383, 384, 385, 390, 393.

Plants not cespitose. Culms acutely angled, 10–110 cm, scabrous. Leaves: basal sheaths red-brown; sheaths of proximal leaves glabrous, fronts lacking spots and veins, apex truncate; blades epistomic, 2–4.5 mm wide, adaxially papillose. Inflorescences: proximal bract subequal to inflorescence, 1.5–4 mm wide. Spikes erect; proximal 2–3 spikes pistillate, 1.2–4.2 cm × 3–5 mm, base obtuse or acute; terminal 1–2 spikes staminate. Pistillate scales dark purple-brown or black, shorter than perigynia, apex obtuse, awnless. Perigynia ascending, pale brown with red-brown or black spots on apical 1/2, occasionally black on apical 1/2, 3–9-veined on each face, somewhat flattened, tightly enclosing achenes, stipitate, ellipsoid or obovoid, 2–3.7 × 1.1–2.1 mm, somewhat leathery, dull, base truncate, distended, apex obtuse or rounded, papillose; stipe 0.1–0.3 mm; beak red-brown or black, 0.1–0.2 mm, orifice scabrous. Achenes not constricted, whitish iridescent, base adnate to perigynium. 2n = 83, 84, 85.

Phenology: Fruiting Jul–Aug.
Habitat: Wet meadows
Elevation: 0–200 m


V23 702-distribution-map.jpg

Greenland, St. Pierre and Miquelon, N.B., Nfld. and Labr., N.S., P.E.I., Que., Conn., Maine, Mass., Mich., N.H., N.Y., Vt., Europe, w. Asia.


Plants of Carex nigra are variable in height and degree of development of rhizomes, but are not separable into distinct taxa. Much less morphologic or ecotypic variation appears to exist in North America than in Europe (A. O. Chater 1980). In North America, C. nigra hybridizes with C. stricta, C. aquatilis, C. paleacea, C. subspathacea, and C. salina. It is a member of the C. acuta subgroup, based on the veined, stipitate perigynia distended by the base of the achenes; it differs from the related sympatric C. lenticularis by the rhizomatous habit, dark green leaves, black scales and perigynia, and short inflorescence bract.

Carex nigra appears to be declining in abundance in southern New England as a result of changing patterns of land use and the loss of wet fields and pastures.

Selected References


Lower Taxa

... more about "Carex nigra"
Lisa A. Standley +, Jacques Cayouette +  and Leo Bruederle +
(Linnaeus) Reichard +
Carex acuta var. nigra +
Carex noir +
Greenland +, St. Pierre and Miquelon +, N.B. +, Nfld. and Labr. +, N.S. +, P.E.I. +, Que. +, Conn. +, Maine +, Mass. +, Mich. +, N.H. +, N.Y. +, Vt. +, Europe +  and w. Asia. +
0–200 m +
Wet meadows +
Fruiting Jul–Aug. +
Fl. Moeno-Francof. +
Illustrated +
Carex ×aquanigra +, Carex nigra var. strictiformis +  and Carex vulgaris var. strictiformis +
Carex nigra +
Carex sect. Phacocystis +
species +