Carex bicolor All.
Fl. Pedm. 2: 267. 1785.
Nomenclatural section used by Flora of North America project subgenus Carex, sect. Racemosae G. Don
No synonymy in Kartesz (1994).
Plants caespitose. Plants less than 15 cm high (on Arctic islands); (3.5–)7–12(–20) cm high. Roots pallid-brown. Ground level or underground stems horizontal, or not developed horizontally or vertically; compact. Scales absent. Aerial stems erect, or decumbent; filiform (0.2–0.3 mm in diameter); triangular in cross section; glabrous (slightly scabrous at the apex). Leaves mostly basal. Sheaths green (soon fading to pallid-brown). Ligules present. Blades straight; linear; strongly keeled; not septate nodulose; glabrous (glaucous). Blades adaxial surface glabrous.
Flowering stems about as high as the leaves, or conspicuously taller than the leaves. Leaf or reduced bract closely associated with the base of the inflorescence present (equalling or slightly longer than the inflorescence); conspicuous and leaf-like (rarely), or reduced, or scale-like (usually); shorter than the apex of the inflorescence; 0.2–1 cm long; with sheath shorter than the blade, or sheathless. Inflorescence spicate; 1–1.5 cm long; 5–10 mm wide. Pedicels smooth. Inflorescence multispicate; 2–3 spikes; lateral spikes borne on pedicels (that are sometimes very short). Individual spike(s) ascending. Terminal spike staminate at the base. Cladoprophyll present at the base of the peduncle of lateral spikes. Staminate flowers inconspicuous. Floral scales shorter than the perigynium in fruit; brown, or black (reddish); with margins darker in colour than the midvein; ovate; 1.9–2.5(–3.8) mm long; 1.2–1.4 mm wide; glabrous. Perianth absent. Anthers 1.3–1.6 mm long. Styles slender, extending beyond the beak. Stigmas per style 2. Fruit surrounded by a perigynium. Perigynia fused to the apex except for a small aperture through which the style protrudes; broadly ovate, or elliptic; 1.8–2.2 mm long; 1.1–1.5 mm wide; sessile; erect or ascending; straw-coloured, or green; surface dull; glabrous; papillose (seen at 10–40X); appearing nerveless (or very finely nerved); with 2 keels; apices merely conical or rounded. Achenes filling the perigynia; lenticular.
Chromosome information. 2n = 50 and 52.
Distribution. Circumpolar. Low arctic, or alpine (in Central Europe). Range in the Canadian Arctic Archipelago limited. Uncommon. Arctic Islands: Baffin (Iqaluit (new since Porsild, 1957), Kimmirut, and Dorset Island), Southampton (Coral Harbour and Duke of York Bay), Coats (Cairn Cove; the latter two are new records since Porsild, 1957).
Ecology and habitat. Substrate wet meadows, around the margins of ponds, tundra, sea shore (on upper sandy beaches); imperfectly drained; calcareous; sand, silt; with low organic content, or with high organic content. Typically found in small patches with other Carex. Not infrequent around the margins of pools where there is little competition from plants of ranker growth. It is also found on patches of bare, wet mud and in open areas in marshes.
Notes. Polunin (1940) described this species as "a characteristic and attractive little sedge, with more or less pendulous spikes of rounded, pastel-green fruits peeping out from behind dark scales". He noted that is varies considerably in luxuriance and has culms which arch in all directions.
Illustrations. • Herbarium specimen. Delicate plants less than 10 cm high. CAN 258601. • Close-up of Inflorescence. Terminal flowers pistillate, perigynia with two stigmas. Inconspicuous staminate flowers at the base of the terminal spike. Note the "bi-colored" scales. • Arctic Island distribution.
Cite this publication as: Aiken, S.G., Boles, R.L., and Dallwitz, M.J. 1999 onwards. ‘Cyperaceae of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval.’ Version: 6th November 2000. http://http://www.mun.ca/biology/delta/arcticf/. Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993, 1995, 2000) should also be cited (see References).
