Flora of the Canadian Arctic Archipelago

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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

Draba oblongata R. Br. ex DC.

Brassicaceae (Cruciferae), Draba family.

Published in Syst. Nat. 2: 342. 1821.

Type: Canada: Nunavut, Baffin Island, Bylot Island, Possession Bay, leg. E. Sabine. Mulligan (1974). Holotype: BM.

Synonymy. Draba groenlandica E. Ekman, Svensk Bot. Tidskr. 23: 486. 1929.

Draba arctica J.Vahl subsp. groenlandica (E. Ekman) Böcher, in Böcher et al., Grønlands flora 92. 1968.

Vegetative morphology. Plants 2–6 cm high; perennial herbs; caespitose (small plants). Taproot present. Caudex present (unbranched or branched). Aerial stems erect. Aerial stem trichomes spreading. Leaves mainly basal; alternate; marcescent. Petioles absent. Leaf blades simple. Leaf blade bases truncate, or attenuate. Leaves not grass-like. Blades 8–12(–15) mm long (flowering stem leaves 4–6(-8) mm long), (2–)2.5–3.5(–4) mm wide (widest leaves sometimes on flowering stems), spreading, oblanceolate, appearing single-veined. Blade adaxial surface hairy (variable, some long stiff hairs to 1 mm long, sometimes a mixture of large, unbranched and smaller occasionally forked trichomes), hairs stellate, simple, and branched, hairs moderately dense or dense, hairs white, or translucent. Blade abaxial surface hairy, hairs villous (with predominantly straight hairs) or tomentose (when many hairs are branched), hairs moderately dense or very dense, hairs white, hairs curved or irregularly branched, hairs appressed. Blade margins entire (basal leaves) or dentate (sometimes with a few small teeth, usually on flowering stem leaves), with non-glandular hairs; apices acute, or obtuse.

Reproductive morphology. Flowering stems two or more per plant; with leaves (one or two). Flowering stems hairy. Flowering stems villous, or tomentose. Flowering stem hairs simple, or branched; white or translucent. Inflorescences racemose; dense (in flower), or diffuse (in fruit); 1.5–2 cm long (in flower to 7 cm long in fruit); 10–15 mm wide (in flower); elongating as the fruit matures. Pedicels with non-glandular hairs. Flowers per inflorescence 3–7(–9); small; radially symmetrical (actinomorphic). Sepals conventional; 4; free; 0.7–1.1 mm long; 2(–3) mm wide; green and purple (sometimes yellow); herbaceous. Calyx hairy. Calyx hairs villous (a few long hairs); non-glandular; white or translucent. Petals conventional; free; 4; yellow (cream); without contrasting markings (broader than sepals); obovate; slightly lobed or undulating; 3.5–4 mm long; 1.6–2 mm wide. Stamens 6; stamen filaments markedly unequal in length; stamen filaments glabrous. Anthers yellow; ovoid; 0.3–0.5 mm long. Ovary superior; carpels 2; syncarpous. Ovaries ovate (narrowly); hairy; tomentose. Ovary hairs very dense; white; appressed; branched (irregularly). Styles 1; thick and short; 0.2–0.4 mm long; straight. Stigmas per ovary 1. Placentation parietal. Ovules per ovary (12–)20–28. Fruit stalked; stalk 4–6 mm long; dry; a silique; ovoid; green at maturity; 6–7.5 mm long; 2–2.5 mm wide; hairy (with a glabrescent pubescence of short-stalked branched trichomes); surface appearing veinless; distinctly flattened; dehiscent; shedding the outer walls to expose a thin inner wall, with the seeds attached at the margins on either side. Styles persisting in fruit 0.4–0.6 mm long. Seeds (12–)20–28; 0.8–1 mm long; brown; surfaces smooth.

Chromosome information. 2n = 64.

2n (8x) = 64. Heilborn (1941, Greenland, count probably made on type material of D. groenlandica); Holmen (1952, Greenland); Jørgensen et al. (1958, Greenland); Böcher (1966a, Greenland); Zhukova (1967a, northeastern Asia); Mulligan (1971a, 1974, North America); Petrovsky and Zhukova (1981, Wrangel Island); Zhukova and Petrovsky (1984, northeastern Asia); Mulligan (2003).

Ploidy levels recorded 8x.

Ecology and habitat. Substrates: wet meadows, river terraces, ridges; imperfectly drained moist areas, dry; gravel, sand, clay, moss; with low organic content, with high organic content; calcareous. This species occurs both in snow patches and moist-wet areas with open soil, on ridges and exposed outcrops with open gravel.

North American distribution. Alaska (?), Yukon (?), Northwest Territories Islands, Nunavut Islands, continental Nunavut. Range in the Canadian Arctic Archipelago widespread. Common. High Arctic. Arctic islands: Devon (?), Ellesmere, Axel Heiberg, Parry islands (Bathurst, Melville, Prince Patrick), Cornwallis, Banks, Victoria, Prince of Wales, Somerset, Southampton.

Northern hemisphere distribution. Amphi-Beringian, or North American. Taimyr – Severnaya Zemlya, Kharaulakh, West Chukotka, Wrangel Island, East Chukotka, North Alaska – Yukon (?), Central Canada, Ellesmere Land – Peary Land, West Greenland, East Greenland.

General notes. Elven et al. (2003) noted that the name D. oblongata was for a long time misapplied to a yellow-flowered species (D. micropetala Hooker, a good species also in the flora region). The name D. oblongata has been proved to belong to, and to have priority for, a white-flowered species in ser. Cinereae, later described and generally known as D. groenlandica E. Ekman (see Mulligan 1974a). Draba oblongata R. Br. [(1819), List Pl. Ross Voy. App. 143] is a nomen nudum.

Elven et al. (2003) stated that whether the species occurs in northern Europe has been investigated, with the discovery (2001) of collections from northern Spitsbergen that resemble D. oblongata in most characters. The site is inaccessible, and it was difficult to base a firm conclusion on the few specimens available.

There are specimens of this species from Siberia: Taimyr and Lena delta (Petrovsky, personal communication, 2002), and records of the plants in the lower Lena River region were confirmed in 2004 by Elven (personal communication, 2005).

Maessen et al. (1983) studied resource allocation strategies for a range of vascular plant species of a High Arctic lowland oasis, located adjacent to Alexandra Fjord, Ellesmere Island, Nunavut. Species such as Cochlearia and Draba (groenlandica) oblongata, which occupied disturbed habitats, had a large proportion of resources allocated to sexual reproductive tissue.

Illustrations. • Close-up of pressed plant. Plant with basal rosette of oblanceolate leaves, flowering stems with at least one leaf, petals cream-yellow, and the remains of the siliques showing ovoid fruit with thick short styles. Nunavut, Ellesmere Island, Vendom Fiord. Blachut and Wilkins. 10 July, 1973. CAN 473912. • Close-up of basal leaves. Oblanceolate leaves densely covered with glabrescent long villous hairs. Note the adaxial leaf surface is almost glabrous. Nunavut, Ellesmere Island, Cape Belknap. P.F. Bruggeman. 7 August, 1951. DAO 561659. • Close-up of leaf on the flowering stem. Ovate leaf on stem with slight indentations on the margins. Note sepals with a few straight hairs, pale cream entire petals that are conspicuously longer than the sepals, and densely hairy ovaries. Nunavut, Ellesmere Island, Cape Belknap. P.F. Bruggeman. 7 August, 1951. DAO 561659. • Close-up of young fruit. Inflorescence elongating in fruit. Note ovate shaped fruits covered with irregularly branched hairs, and the short style. Nunavut, Ellesmere Island, Cape Belknap. P.F. Bruggeman. 7 August, 1951. DAO 561659. • Close-up of fruits. Fruit ovoid, green at maturity, with surface sparsely covered with irregularly branched hairs. N.W.T., Bank Island, Masik River. Chromosome count n=32. Mason 91. 19 July, 1968. DAO 561333. • Close-up of fruits. Upper, entire fruit with surface sparsely covered with irregularly branched hairs. Bottom, one wall of the silique has shed. Bank Island, Masik River. Chromosome count n=32. Mason 91. 19 July, 1968. DAO 561333. • 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.

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