Carex bigelowii Torrey ex Schweinitz (C. rigida Good., Non Schrank; C. hyperborea Drejer)

Brooker, R; Carlsson, B; Callaghan, T

A clonal perennial sedge with creeping rhizomatous growth. Mature clones with a below-ground moderately branched tiller system have up to 27 generations of connected tillers. Rhizomes stout; roots grey-brown, often as thick as rhizomes (Jermy et al. 1982). Culms rigid, up to 30 cm, sharply three-angled (occasionally four-angled; Sell & Murrell 1996) and usually rough towards the top, developing on tiller generations 3-5 (the youngest generation being generation 1). Leaves present on tillers 1-3 (possibly 4), 2-4(-7) mm wide and shorter than stems, up to 25 cm long, hairless and somewhat glaucous, recurved and keeled. The leaf margins roll outward on drying, and leaf tissue turns reddish-brown with senescence. Ligules 1-2 mm long, ? triangular, with an acute apex. Basal sheaths reddishbrown, shiny and persistent, with the lower sheaths leafless. Inflorescence one-eighth to one-fifth (if short, one-half) the length of the stem with 1 (rarely 2) male and generally 2-3 (possibly 1-6) female spikes. Lowest bract leaf-like, shorter than the inflorescence; all other bracts small, with all bracts having large, blackishbrown auricles. Male spike 5-20 x 3-5 mm, purplishblack, subsessile or with a peduncle up to 0.5 cm. Male glumes 3-4 mm long with a pale midrib and base, the apex being acute/rounded. Female spikes 5-15 x 3-5 mm, closely spaced, or with the lower spike more distant; peduncles absent or very short. Female glumes 2.5- 3.5 mm long, purplish-black with pale (sometimes inconspicuous) midrib, mostly equalling utricle in length but not in width, ovate and obtuse. Utricle 2- 3 mm, smooth and green below, purplish-black above with a short, slightly notched beak up to 0.2 mm, and 2 stigmas. Nut 2 mm long, ovate and biconvex. Airdried nut mass at individual sites ranges between 0.2 and 0.5 mg (excluding utricle) and 0.1-1.7 mg. Carex ? 2001 British Ecological Society Correspondence: R. W. Brooker (e-mail r.brooker@ceh.ac.uk). *Abbreviated references are used for standard works, see Journal of Ecology (1975), 63, 335-344. Nomenclature of vascular plants follows Fl. Eur., for bryophytes Smith (1978), and for lichens Purvis et al. (1992). bigelowii (stiff sedge) is similar to mountain varieties of C. nigra but distinguishable by reddish-brown (not blackish-brown) basal leaf sheaths (Stace 1997).

Carex bigelowii Torrey ex Schweinitz (C. rigida Good., Non Schrank; C. hyperborea Drejer)

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