Flora of the Canadian Arctic Archipelago
English: Bristle sedge,
French: Carex à petite arête,
Inuktitut: Iviit, ivisuka, ivitsuskaka.
Cyperaceae, Sedge family.
Published in Kongl. Vetensk. Acad. Nya Handl. 24: 140. 1803.
Type: Northern Fennoscandia: in lateribus radicibusque irrigius montium per Lapponiam Enontekensem et Nordlandiam Norwegicam septentrionalem, leg. Wahlenberg, selected by Moberg and Nilsson, Nord. J. Bot. 11: 289. 1991. Lectotype: UPS-THUNB 21875.
Vegetative morphology. Plants 4–15 cm high (-35 cm further south); perennial herbs; caespitose (loosely); loosely tufted in several tufts (with short stolons betwen the tufts). Only fibrous roots present. Roots pallid-brown. Ground level or underground stems horizontal; rhizomatous; elongate, or compact (0.2–4(-6) cm long). Ground level or underground stems scales present. Aerial stems erect; filiform (0.5–0.7 mm in diameter). Leaves mainly basal; alternate; marcescent. Petioles absent. Sheaths present; breaking down into fibres (slowly); not forming a conspicuous build-up at the base of the plant; brown, or reddish orange. Ligules present (much wider than long). Leaves grass-like. Blades 10–80(–140) mm long, 0.4–1 mm wide, straight (4–10 per culm), linear, involute (to semicircular), veins parallel. Blade adaxial surface glabrous. Blade abaxial surface glabrous. Blade margins glabrous.
Reproductive morphology. Plants monoecious. Flowering stems circular or oval in cross section. Flowering stems conspicuously taller than the leaves; with leaves (near the base). Leaf or reduced bract subtending the base of the inflorescence absent (proximal scales "blade-bearing"). Inflorescences spicate and head-like (with 4–8 staminate flowers and 3–10 pistillate flowers); 0.6–1.5 cm long; (2–)5–10 mm wide (immature stage; to 11 mm long when mature). Cladoprophylls present. Inflorescence unispicate. Individual spike(s) erect. Terminal spike staminate at the apex (staminate scales appressed). Floral scales shorter than the perigynium in fruit; orange-brown; with margins and sometimes midvein paler in colour than the adjacent area of the scale; reflexed; ovate; falling early; (2.4–)2.8–3.2 mm long (wider than half the length of the perigynia); 1.8–2.2 mm wide; glabrous. Flowers unisexual. Staminate flowers conspicuous (as a small tuft). Perianth represented by a perigynium. Stamens present (staminate flowers), or absent (pistillate flowers); 3. Anthers 1.8–2.2 mm long. Ovary superior; carpels 3; syncarpous. Perigynia sessile. Styles 3; partially fused; slender, not extending beyond the beak. Stigmas per ovary 3. Placentation basal. Ovules per ovary 1. Fruit surrounded by a perigynium. Perigynia fused to the apex except for a small aperture through which the style protrudes; lanceolate (subulate); 3.4–4.7(–6) mm long; 0.5–0.8 mm wide; reflexed; green (pale), or straw-coloured, or golden brown; membranous; surface dull; glabrous; faintly veined; not keeled; apices merely conical or rounded (from which a stiff, bristle-like rachilla, 0.5–2.8 mm long, projects beyond the orifice of the beak, style not exerted). Fruit dry; an achene; indehiscent. Achenes lenticular; not filling the upper part of the perigynia.
Chromosome information. 2n = 48, 50, 56, and 58.
2n = 48–58.
2n = 48. Dietrich in Löve (1972); Yurtsev and Zhukova (1982, northern Siberia);
2n = 50. Löve (1981d, northern Canada);
2n = 56 Levan, in Löve and Löve (1942, northern Europe);
2n = 58. (1956, Iceland); Moore and Chater (1971, South America).
Ecology and habitat. Substrates: wet meadows, river terraces (and deltas), slopes, around the margins of ponds; imperfectly drained moist areas, seepage slopes; sand, silt, till (on talus slopes); calcareous. Found in springy areas and on wet sand along rivers.
North American distribution. Porsild (1957) mapped one location in Frobisher Bay on Baffin Island, but we have been unable to locate the specimen. Alaska, Yukon, Northwest Territories Islands (?), continental Northwest Territories, Nunavut Islands, continental Nunavut, northern Quebec, Labrador. Range in the Canadian Arctic Archipelago limited. Rare. Low Arctic. Arctic islands: Baffin, Victoria (Holman).
Northern hemisphere distribution. Circumpolar, or circumboreal (arctic-alpine in Europe and North America, in Asia only disjunctly alpine). Northern Iceland, Northern Fennoscandian, West Alaska, North Alaska Yukon, Central Canada, Labrador Hudson Bay, West Greenland, East Greenland.
General notes. Since Porsild (1957), one specimen (CAN 485156) was collected on Victoria Island at Holman, which is a considerable range extension.
Reznicek (1990) illustrated the rachilla of C. microglochin and noted that it is very large, but only one-veined. It is terete and smooth. Internally, surrounding the single central vascular strand is a thick layer of spongy parenchyma, making the rachilla a relatively soft, more or less easily bent structure. It is a striking contrast to the rachillas in other species that he studied.
Cochrane (2002, p. 531) noted that "Carex michroglochin subsp. microglochin is usually rare to occasional in subarctic North America and scattered in the Cordilleran region. It can be locally abundant (e.g., Brooks Range, Alaska) or even dominant (e.g., western Newfoundland) despite its very spotty geographic range... Carex michroglochin subsp. microglochin is an inconspicuous but interesting little plant, distinctive in having a well-developed rachilla very similar in appearance to the exserted style of C. pauciflora Lightfoot. The long pointed perigynia, which mature quickly and detach easily, are probably dispersed by animals (Fernald 1926; Savile 1972)."
Illustrations. • Close-up of plant. Plant with rhizomes, aerial stem erect and filiform. Inflorescence unispicate, staminate at the apex. Perigynia at right angles to the rachis and reflexed. N.W.T., Victoria Island, Holman. CAN 485156. • Close-up of young inflorescence. Unispicate inflorescence with upward pointing floral scales surrounding young perigynia at the base. These have long-beaked apices from which a stiff, bristle-like rachilla projects beyond the three stigmas. The white filaments at the apex indicate the position of the staminate flowers. N.W.T., Victoria Island, Holman. CAN 485156. • Maturing spike. Maturing spike with some of the floral scales fallen off, others remaining in the centre of the spike. The lowest perigynia are reflexed. The mid-spike perigynia are at right angles to the rachis in the process of becoming reflexed. The staminate flowers at the apex are indicated by the white filaments (anthers have fallen). N.W.T., Victoria Island, Holman. CAN 485156. • Arctic Island Distribution.
This publication is available on the internet (posted May 2011) and on CD-ROM (published in 2007). These versions are identical in content, except that the errata page for CD-ROM is accessible on the main index page of the web version.
Recommended citation for the web-based version of this publication: Aiken, S.G., Dallwitz, M.J., Consaul, L.L., McJannet, C.L., Boles, R.L., Argus, G.W., Gillett, J.M., Scott, P.J., Elven, R., LeBlanc, M.C., Gillespie, L.J., Brysting, A.K., Solstad, H., and Harris, J.G. 2007. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. NRC Research Press, National Research Council of Canada, Ottawa. http://nature.ca/aaflora/data, accessed on DATE.
Recommended citation for the CD-ROM version of this publication: Aiken, S.G., Dallwitz, M.J., Consaul, L.L., McJannet, C.L., Boles, R.L., Argus, G.W., Gillett, J.M., Scott, P.J., Elven, R., LeBlanc, M.C., Gillespie, L.J., Brysting, A.K., Solstad, H., and Harris, J.G. 2007. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. [CD-ROM] NRC Research Press, National Research Council of Canada, Ottawa..