General: Perennial, loosely tufted or turf-forming herb from slender, much-branched rhizomes; stems arising singly, slender, triangular in cross-section, at least above, (15) 20-60 cm tall.
Leaves: Basal sheaths brownish to reddish-brown, cross-wrinkled, persistent, lacking young basal leaves at flowering time; leaves basal or stem, shorter than the stem, the stem leaves 2 or 3; blades 0.8-1.5 (2) mm wide, elongate, narrow and folded towards the tips or triangular in cross-section, the uppermost leaves with reduced blades usually shorter than the well-developed sheaths.
Flowers: Spikes 2 to 8, terminal, erect, in compact to open, umbrella-like cymes, the stalks slender, unequal, circular in cross-section, tapered, not evidently compressed, minutely stiff short-hairy, egg-shaped and 0.5-1 cm long in flower, 1.5-2 (2.5) cm long in fruit; anthers mostly 1-3 mm long; involucral bracts several but only one of them evidently green and leaflike, usually shorter than the inflorescence, not purplish basally.
Fruits: Scales blackish-green to greenish-brown or greyish, egg-shaped to lanceolate, appressed to ascending, the slender midribs not reaching the tips, blunt; perianth bristles numerous, white or whitish, many times longer than the achenes; achenes straw-coloured or light brown, 2.5-3.5 mm long, narrowly egg-shaped to narrowly lanceolate.
1. Spikes 2 or more, subtended by one or more leaflike involucral bracts.
2. Leaves narrow, elongate, folded or triangular in cross-section; involucral bracts solitary, shorter than the inflorescence...........................................E. gracile
2. Leaves mostly flattened, except at the tips; involucral bracts 2 or more with the longest equalling or surpassing the inflorescence.
3. Spikes crowded, the scales with several conspicuous ribs; perianth bristles orange-brown or coppery...........................................E. virginicum
3. Spikes loosely aggregated, the scales with single ribs; perianth bristles creamy-white to tawny.
4. Midribs of scales extending to the tips, sheaths green...............E. viridcarinatum
4. Midribs of scales not extending to the tips; sheaths blackish..........E. angustifolium
1. Spikes solitary, not subtended by leaflike involucral bracts.
5. Plants rhizomatous or stoloniferous, usually with solitary stems...............E. scheuchzeri
5. Plants without stolons or rhizomes, densely tufted.
6. Scales with broad, pale margins, the basal ones reflexed................E. vaginatum
6. Scales without pale margins, the basal ones not reflexed.
7. Perianth bristles pure white with silky sheen; plants 6-25 cm tall..............E. callitrix
7. Perianth bristles cream-coloured or yellow-tinged; plants 30-60 cm tall..............E. brachyantherum
Source: Illustrated Flora of British Columbia
Habitat / Range
Bogs, marshes and lakeshores in the lowland, steppe and montane zones; infrequent in BC, absent from NW BC, Queen Charlotte Islands and Vancouver Island; circumpolar, N to AK and NT, E to NF and S to ME, MA, PA, IN, IL, IA, NE, CO, ID and CA; Eurasia.
The table below shows the species-specific information calculated from original data (BEC database) provided by the BC Ministry of Forests and Range. (Updated August, 2013)
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