Flora of the Canadian Arctic Archipelago
English: Black sedge,
Inuktitut: Iviit, ivisuka, ivitsuskaka.
Cyperaceae, Sedge family.
Published in Acta Phytogeogr. Suec. 13: 193. 1940.
Type: Sweden: Lapponia Tornensis, Karesuando, Moscana, 26.07.1933, leg. H. Smith. Holotype: UPS.
Synonymy. Carex capitata L. subsp. arctogena ( Harry Sm. ) Hiitonen, Luonnon Tutkija 48: 55. 1944.
Carex capitata L. subsp. arctogena (Harry Sm.) Böcher ex Á. Löve, D. Löve, and B.M. Kapoor, Arct. Alp. Res. 3(2): 144. 1971.
Carex capitata L. f. arctogena (Harry Sm.) Raymond, Contr. Inst. Bot. Univ. Montréal 64: 38. 1949.
Carex capitata L. var. arctogena ( Harry Sm.) Hultén, Kongl. Svenska Vetensk. Acad. Handl. ser. 4, 7(1): 38. 1958.
Vegetative morphology. Plants 10–25 cm high; perennial herbs; caespitose; in dense single compact tufts. Only fibrous roots present. Roots pallid-brown. Ground level or underground stems horizontal; compact. Aerial stems erect (in short plants), or ascending (taller plants); filiform (CAN 283963), or not filiform (CAN 17382, younger specimen). Leaves mainly basal; alternate; dying annually and non-persistent (at least the blades), or marcescent (sheaths). Petioles absent. Sheaths present; persisting; forming a conspicuous build-up at the base of the plant; greyish brown (with age), or brown (rusty); with the margins fused to the apex (with membranous margins); glabrous; sheath collars absent. Ligules present; 0.4–0.6 mm long; membranous; glabrous; ovate-oblong. Ligule apices obtuse. Leaves grass-like. Blades 50–120 mm long, 0.4–0.6 mm wide, appressed to the stem or spreading, straight, linear, channelled, veins parallel. Blade adaxial surface glabrous. Blade abaxial surface glabrous. Blade margins entire or serrate (at the apex), scabrous; apices acuminate.
Reproductive morphology. Plants monoecious. Flowering stems two or more per plant; about as high as the leaves, or conspicuously taller than the leaves; without leaves. Leaf or reduced bract subtending the base of the inflorescence absent. Inflorescences spicate; dense; ovate, or globose or sub-globose; 0.5–0.6 cm long; 3.5–4.5 mm wide. Cladoprophylls absent. Inflorescence unispicate. Individual spike(s) erect. Terminal spike staminate at the apex (with a conspicuous tuft). Floral scales shorter than the perigynium in fruit (with broad hyaline margins); orange-brown; with margins the same colour as the body of the scale, or with margins paler than body of the scale; obovate; 2–2.5 mm long; 1.5–2 mm wide; glabrous; apex retuse. Flowers unisexual. Staminate flowers inconspicuous. Perianth represented by a perigynium. Stamens present (staminate flowers), or absent (pistillate flowers); 3. Anthers 0.9–1.1 mm long. Ovary superior; carpels 3; syncarpous. Perigynia sessile. Styles present; 2; partially fused; slender, not extending beyond the beak. Stigmas per ovary 2. 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; broadly ovate; 2–2.5 mm long; 1.5–1.8 mm wide; erect or ascending; green; membranous; surface dull; glabrous (over most of the surface); serrulate (near the apex of the perigynia, cf. C. capitata); appearing veinless; inflated; with 2 keels; apices beaked with a long beak (that is abruptly distinct from the body of the perigynium, a contrast with C. capitata). Fruit sessile; dry; an achene; ellipsoid; indehiscent. Achenes lenticular; not filling the upper part of the perigynia. Seeds 1.
Chromosome information. 2n = 50.
2n = 50. Jørgensen et al. (1958, Greenland); Moore and Calder (1964, western Canada); Löve and Löve (1966b, northeastern USA), Löve (1981d, northern Canada); Engelskjøn and Knaben (1971, northern Norway); Löve et al. (1971, western North America).
North American distribution. Nunavut Islands, northern Quebec, Labrador. Range in the Canadian Arctic Archipelago limited. Rare. Low Arctic. Arctic islands: Baffin.
Northern hemisphere distribution. Amphi-Atlantic. Northern Fennoscandian, Labrador Hudson Bay, West Greenland, East Greenland.
General notes. A recent investigation based on Scandinavian material (Reinhammer 1999) strongly supported the status of this species as distinct from C. capitata. There are consistent differences in genetic markers between C. arctogena and C. capitata, consistent differences in morphology and ecology, a different distribution pattern (even if overlapping), and not a single documented intermediate or hybrid. Elven et al. (2003) consider they are unambiguously good species both 'biologically' and morphologically.
Murray (2002) in the Flora of North America treatment states that although these two species are readily distinguished in Scandinavia and Russia (Reinhammer 1999 and Egorova 1999, respectively) the situation is not as clear in North America. Murray noted that in North America two taxa may be distinguished but there are also numerous specimens of uncertain determination. He included both species under C. capitata, but concluded that separate status at some rank may be appropriate for the taxon "arctogena" in North America and urged that, when making new collections, it is important to pay close attention to habitat and habit. Carex capitata occurs in boreal mires and is mat-forming; the pistillate scales are much shorter and narrower than the perigynia with narrow hyaline margins; the perigynia taper gradually to the glabrous beak. Carex arctogena grows in alpine heaths and is tufted; the pistillate scales are as long as the perigynia and with broad hyaline margins; the perigynia have an abrupt beak and may be sparingly serrulate. All specimens of C. capitata from the Canadian Arctic Archipelago that we have checked to date have been redetermined as C. arctogena.
Illustrations. • Close-up of plant. Tussock sedge with unispicate spikes born on leafless flowering stems. Nunavut, Kimmirut. 26–28 July, 1936, N. Polunin 1213. CAN 17382. • Spike at anthesis. Spicate inflorescence with terminal staminate flowers at anthesis, perigynia with long beaks and styles with 2 stigmas. Nunavut, Kimmirut. 26–28 July, 1936, N. Polunin 1213. CAN 17382. • Mature inflorescence. Mature inflorescene with perigynia that have somewhat serrulate broad hyaline margins and an abrupt beak. A few white filaments in a tuft at the apex are the remains of the staminate flowers. Nunavut, Baffin Island, Beekman Peninsula. McLaren 153. CAN 283963. • 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..