Flora of the Canadian Arctic Archipelago
Brassicaceae (Cruciferae), Draba family.
Published in In Grøntved, Vasc. Pl. Arct. N. Amer. 83. 1936.
Type: Greenland: Godhavn, 08.1923, leg. E. Ekman Holotype: S.
Synonymy. Draba groenlandica E. Ekman var. arctogena E. Ekman, Svensk Bot. Tidskr. 23: 489. 1929.
Vegetative morphology. Plants 5–20 cm high; perennial herbs; caespitose. Taproot present. Ground level or underground stems absent. Caudex present (slightly developed, branching at ground-level into individual rosettes, from a strong taproot and with relatively little build-up of marcescent leaves). Aerial stems erect. Aerial stem trichomes spreading. Leaves mainly basal, or basal in a rosette; alternate; marcescent. Petioles absent. Leaf blade bases truncate, or attenuate. Leaves not grass-like. Blades 5–20 mm long, (1–)2–3.5(–4.5) mm wide, spreading, oblanceolate or obovate, appearing single-veined or with inconspicuous veins. Blade adaxial surface hairy, hairs simple or stellate, hairs dense, hairs white, or translucent. Blade abaxial surface hairy, hairs moderately dense or very dense, hairs white, hairs irregularly branched or stellate, hairs spreading. Blades not lobed (usually). Blade margins entire (usually: sometimes with one or two small teeth per side), with non-glandular hairs (similar to those on the leaf surface); apices acute (narrowly to broadly).
Reproductive morphology. Flowering stems two or more per plant; with leaves (occasionally), or without leaves (more usually). Flowering stem hairs simple, or branched (irregularly), or stellate; shorter than the diameter of the flowering stem; white or translucent. Inflorescences head-like (in flower); dense (in flower); globose or sub-globose; elongating as the fruit matures. Pedicels present (2–5 mm long); with non-glandular hairs. Flowers per inflorescence (2–)5–15; small. Sepals conventional; 4; free; 1–1.5 mm long; 2–2.5 mm wide; green (mainly), or purplish red (tinged). Calyx hairy. Calyx hairs non-glandular; white or translucent (simple). Petals conventional; free; 4; yellow; oblanceolate, or spatulate; unlobed; (4.5–)5–6 mm long; 1.9–2.2 mm wide. Stamens 6; stamen filaments markedly unequal in length; stamen filaments glabrous. Anthers yellow; sub-globose; 0.4–0.6 mm long. Ovary superior; carpels 2; syncarpous. Ovaries ovate; hairy. Ovary hairs very dense; white; appressed; stellate. Styles 1; thick and short; 0.5–1 mm long; straight. Stigmas per ovary 1. Placentation parietal. Ovules per ovary 22–26. Fruit stalked; stalk 2–4(–5) mm long; dry; a silique; ovoid; green at maturity (olivaceous); 6.5–10 mm long; 3–4 mm wide; hairy (with irregularly branched hairs); 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 0.5–1 mm long. Seeds 22–26; 0.9–1.1 mm long; brown (reddish brown); surfaces smooth (at 10×), rugose (at 40×).
Chromosome information. 2n = 48.
2n (6x) = 48. Heilborn (1941, Greenland); Holmen (1952, Greenland); Böcher (1966a, Greenland); Zhukova and Petrovsky (1971, Wrangel Island, 1984; northeastern Asia); Zhukova et al. (1973, northeastern Asia); Petrovsky and Zhukova (1981, Wrangel Island).
Ploidy levels recorded 6x.
North American distribution. Nunavut Islands.
Northern hemisphere distribution. Amphi-Atlantic, or circumpolar (?). Northern Iceland (?), Svalbard Franz Joseph Land (?), Kharaulakh (?), YanaKolyma (?), West Chukotka (?), Wrangel Island (?), Ellesmere Land Peary Land, East Greenland.
General notes. Elven, in May 2003, when he visited Canada, drew attention to the presence of this species among Draba specimens at both CAN and DAO, many of them previously filed under D. oblongata.
The distribution is unclear. North American and northwestern European authors consider this a species of Greenland, northeastern North America, and perhaps Iceland, and the arctic Norwegian islands (Jan Mayen, Bear Island, Svalbard). Russian authors and Petrovsky (in Elven et al. 2003) indicate it as distributed throughout eastern Siberia and Russian Far East eastwards from Kharaulakh and into Alaska. Elven (personal communication, 2005) stated he had yet to see convincing specimens from outside the amphi-Atlantic regions.
The treatment presented here is provisional pending further study.
Illustrations. • Close-up of leaf surfaces. Leaves oblanceolate, or obovate, 5–20 mm long, (1-)2–3.5(-4.5) mm wide and margins usually entire. Nunavut, Ellesmere Island, Lake Hazen. J. Soper 8120. 4 July, 1958. CAN 483650. • Close-up of plant. Plant with tight rosettes of leaves, short flowering stems with compact flowering heads of yellow flowers and the long remains of last season's inflorescences that are much taller after the inflorescences elongated in fruit. Nunavut, Axel Heiberg Island, Flag Hill. M. Kuc. 12 July, 1967. CAN 330976. • Close-up of flowering head. Close-up of flowering stalk with one leaf on the stalk, and a compact flowering head with flowers that have greenish sepals and yellow petals that are conspicuously longer than the sepals. Nunavut, Axel Heiberg Island, Flag Hill. M. Kuc. 12 July, 1967. CAN 330976. • Close-up of plant in fruit. Old plants with small slightly developed caudex, branching at ground-level into individual rosettes, from a strong taproot and with relatively little build-up of marcescent leaves. Nunavut, Ellesmere Island, near Lake Hazen. J. Powell 232. 15 July, 1958. CAN 483651. • Close-up of infrutescence. Relatively small fruit for the species, 6.5–10 mm long, 3–4 mm wide. Olivaceous green at maturity, and covered with irregularly branched hairs. Note styles persisting in fruit 0.5–1 mm long and 24 seeds (12 showing) 0.9–1.1 mm long. N.W.T., Melville Island, Barry Bay. CAN 518533. • 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..