Flora of the Canadian Arctic Archipelago


S.G. Aiken, M.J. Dallwitz, L.L. Consaul, C.L. McJannet, R.L. Boles, G.W. Argus, J.M. Gillett, P.J. Scott, R. Elven, M.C. LeBlanc, L.J. Gillespie, A.K. Brysting, H. Solstad, and J.G. Harris

Carex lachenalii Schkuhr

English: Arctic hare's foot sedge,

French: Carex de Lachenal,

Inuktitut: Iviit, ivisuka, ivitsuskaka.

Cyperaceae, Sedge family.

Published in Beschr. Riedgräs. 51. 1801.

Type: Lectotype selected by Egorova (1999?). However, it is debatable whether the lectotypification of Egorova will stand. There are indications that there is a physical holotype: "Carex lachenalii n. 79", herb. Schkuhr (HAL), Elven (personal communication, 2005).

Synonymy. Carex lagopina Wahlenb., Kongl. Vetensk. Acad. Nya Handl. 24: 145. 1803.

?Carex bipartita All., nom. ambig., Fl. Pedem. 2: 265. 1785.

?Carex tripartita All., Fl. Pedem. 2: 265. 1785.

Vegetative morphology. Plants (8–)10–25(–50) cm high; perennial herbs; caespitose; loosely tufted in several tufts. Only fibrous roots present. Roots pallid-brown. Ground level or underground stems horizontal; compact. Ground level or underground stems scales present (often inconspicuous). Aerial stems erect; not filiform. Leaves mainly basal; alternate; marcescent. Petioles absent. Sheaths present; persisting (the first year); not forming a conspicuous build-up at the base of the plant; greyish brown, or brown (pale brown abaxially, inner band hyaline, slightly red tinged, concave at summit); sheath collars absent. Ligules present; 0.1–0.2 mm long (short); membranous. Leaves grass-like. Blades 50–180 mm long, 0.5–2.5 mm wide, straight, linear, flat or revolute (loosely; not strongly keeled; mid-dark green), veins parallel. Blade adaxial surface glabrous or scabrous (scaberulous). Blade abaxial surface glabrous or scabrous (on margins and midvein). Blade margins scabrous (scaberulous).

Reproductive morphology. Plants monoecious. Flowering stems two or more per plant. Flowering stems triangular in cross section (sometimes with heavy sclerenchyma strands on the angles). Flowering stems conspicuously taller than the leaves; with leaves, or without leaves. Leaf or reduced bract subtending the base of the inflorescence present; reduced, or scale-like; shorter than the apex of the inflorescence (usually, but often inconspicuous); 4–10 mm long; persistent; with sheath shorter than the blade. Inflorescences a spike of spikes; linear, or ovate; (0.5–)1–1.5(–2.5) cm long; 5–15 mm wide. Cladoprophylls absent. Inflorescence multispicate. Inflorescence (2–)3–4(–5) spikes. Individual spike(s) erect, or ascending (the lowermost somewhat distant). Terminal spike staminate at the base (lateral spikes gynecandrous, close or slightly separated, containing 10–20 perigynia). Floral scales shorter than the perigynium in fruit; orange-brown (reddish); with margins and sometimes midvein paler in colour than the adjacent area of the scale (margins narrow and scarious); ovate; 2.3–2.6 mm long; 1.6–2.2 mm wide; glabrous. Flowers unisexual. Staminate flowers inconspicuous. Perianth represented by a perigynium. Stamens present (staminate flowers), or absent (pistillate flowers); 3. Anthers 1.2–1.6 mm long. Ovary superior; carpels 3; syncarpous. Perigynia contracted at the base into a stipe. Styles 2; partially fused; slender, extending beyond the beak. Stigmas per ovary 2. Placentation basal. Ovules per ovary 1. Fruit surrounded by a perigynium. Perigynia with a slit running down the beak on the abaxial side through which the style protrudes; lanceolate (to ovate); (1.5–)2.5–3(–3.8) mm long; 1.2–1.4 mm wide; erect or ascending; straw-coloured (towards the base), or golden brown (towards the apex, when mature); membranous; surface dull; glabrous, or scabrous (with a scaberulous margin towards the beak); faintly veined; with 2 keels; apices beaked with a long beak (0.75–1 mm long; the abaxial suture evident); apex oblique, becoming slightly bidentate. Fruit sessile; dry; an achene; obovate; indehiscent. Achenes lenticular (pale to mid-brown, dull to slightly glossy); filling the perigynia. Seeds 1; 1.1–1.4 mm long (0.6–0.9 mm wide); brown (pale to a mid-brown; dull to slightly glossy).

Chromosome information. 2n = 58–64.

2n = more than 50;

2n = 58. Davies (1956a, 1956, northern Europe);

2n = 58–64.

2n = about 60. Krogulevich (1971, southern and northern Siberia; 1976, northern Siberia);

2n = 60–62. Sokolovskaya and Strelkova (1948a);

2n = 62. Löve and Löve (1956, Iceland);

2n = 64. Heilborn (1939, northern Europe); Flovik, in Löve and Löve (1942, northern Europe); Flovik (1943, Svalbard?); Knaben and Engelskjøn (1967, southern and northern Norway); Yurtsev and Zhukova (1978, eastern Chukotka); Engelskjøn (1979, Bear Island); Murin and Paclova (1979, central Europe).

The comparatively high-ploidy chromosome count 2n = 74 of Löve and Löve (1956 Iceland) should be discounted, as it was also omitted by Löve and Löve (1975). The comparatively low count of 2n = more than 50 (Zhukova (1965), eastern Chukotka, as 'tripartita') should also be checked against voucher and confirmed before it is included.

Ecology and habitat. Substrates: along streams (can be found on the slopes of muddy ravines), lakeshores (on beach ridges and Salix rafts), tundra (and grassy meadows), slopes, snow patches (in Svalbard it occurs on sheltered slopes where the snow accumulates and the soil is quite humic, or at least rich in litter); imperfectly drained moist areas; rocks, gravel, silt, clay, till; acidic. Found in wet sand or gravel by brooks and lakeshores, but not a littoral species (Porsild 1957).

North American distribution. Alaska, Yukon, Northwest Territories Islands (?), continental Northwest Territories, Nunavut Islands, continental Nunavut, northern Quebec, Labrador. Range in the Canadian Arctic Archipelago limited. Uncommon (Low Arctic, boreal, barely entering the archipelago). Low Arctic (a subarctic, boreal species in Canada), High Arctic (in Greenland and Svalbard). Arctic islands: Baffin, Victoria, Southampton, and Coats (Melville Peninsula and Igloolik Island).

Northern hemisphere distribution. Circumpolar, or circumboreal. Northern Iceland, Northern Fennoscandian, Kanin–Pechora, Svalbard – Franz Joseph Land, Polar Ural – Novaya Zemlya, Yamal–Gydan, Taimyr – Severnaya Zemlya, Anabar–Olenyok, Kharaulakh, Yana–Kolyma, West Chukotka, Wrangel Island, South Chukotka, East Chukotka, West Alaska, North Alaska – Yukon, Central Canada, Labrador – Hudson Bay, Ellesmere Land – Peary Land, West Greenland, East Greenland.

General notes. Polunin (1940) discusses the name of this taxon that he called Carex bipartita All. He agreed with Gelting (1934) who considered the familiar salt marsh C. glareosa as a variety of this species and recognised it as C. bipartita var. glareosa (Wahlenb.) Polunin. However, he admitted that seashore plants and individuals occurring away from the shore are referable to a rather variable typical form, and many individuals are intermediate in such characters as the width of the leaves, thickness and rigidity of the culms, and shape of the inflorescence.

Toivonen (2002) reported that ‘C. lachenalii shows a great deal of morphological variation; … most of the variation has no evident taxonomic relevance…" The name Carex bipartita All. has been widely used for the plant in North America. Toivonen (2002) gave reasons why this name should have priority over C. lachenalii. However, the International Code of Botanical Nomenclature (ICBN) has conserved Carex lachenalii over C. tripartita (Greuter et al. 2000) and rejected C. bipartita (McNeill et al. 2006).

Illustrations. • Habitat: Cape Dorset. Yellow-green plants near the marker growing in moist area in the shelter of a rock. Plants also form a dominant zone in lower lying areas of a sedge meadow beside a lake. Nunavut, Baffin Island, Cape Dorset. 3 August, 2005. Aiken and A. Archambault 05–082. CAN. 586953. • Habitat. Isolated plant approximately 15 cm high, growing between the markers. 11 July, 2004. Nunavut, Baffin Island, Ogac Lake. Aiken and LeBlanc 04–064. CAN 586535. • Habitat: exposed tundra. Isolated plant growing in deep lichen mat, near Thule site at the opposite side of island from hamlet. Nunavut, Baffin Island, Cape Dorset. 3 August, 2005. A. Aiken and A. Archambault 05–082. CAN 586953. • Close-up of inflorescence. Compact multispicate inflorescence with terminal and lateral spikes staminate at the base, perigynia with a long beak, stigmas 2. Nunavut, Baffin Island, Ogac Lake. 11 July, 2004. Aiken and LeBlanc 04–064. CAN 586535. • 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.