Flora of the Canadian Arctic Archipelago
English: Norwegian whitlowgrass,
French: Drave des Norvège.
Brassicaceae (Cruciferae), Draba family.
Published in Fl. Norveg. 2: 106. 1772.
Type: Described from Norway. Type possibly in TRH-GUNN (not lectotypified).
Synonymy. Draba rupestris W.T. Aiton, Hortus Kew., ed. 2, 4: 91. 1812.
Draba norvegica Gunnerus var. hebecarpa (Lindbl.) O.E. Schulz, In Engler Das Pflanzenreich, 89: (IV,105), 222. 1927.
Draba hirta L. (1759) nom. rejic. prop. p.p.
Draba hirta var. norvegica (Gunnerus) Lilj.
Vegetative morphology. Plants 4–8 cm high; perennial herbs; caespitose. Taproot present. Caudex present (branching). Aerial stems erect. Aerial stem trichomes spreading, or erect. Leaves mainly basal; alternate; dying annually and non-persistent. Petioles absent. Leaf blades simple. Leaf blade bases attenuate. Leaves not grass-like. Blades 6–14 mm long, 1.8–2.5 mm wide, oblanceolate, appearing single-veined. Blade adaxial surface hairy (hispid), hairs simple (predominantly), hairs sparse (towards the apex), hairs white, or translucent. Blade abaxial surface hairy, hairs sparse or moderately dense (towards the apex), hairs white, hairs straight (hispid, mainly) or irregularly branched, hairs spreading or erect. Blade margins entire (or with 1–3 teeth on each side), with non-glandular hairs (hispid); apices acute.
Reproductive morphology. Flowering stems two or more per plant; without leaves. Flowering stem hairs simple, or branched (irregularly); white or translucent. Inflorescences racemose; elongating as the fruit matures, or not elongating as the fruit matures (stunted plants). Pedicels with non-glandular hairs. Flowers per inflorescence 4–7; small; radially symmetrical (actinomorphic). Sepals conventional; 4; free; 0.8–1 mm long; 2.5–3 mm wide; purple; herbaceous. Calyx hairy. Calyx hairs non-glandular; white or translucent. Calyx margins without cilia. Petals conventional; free; 4; white; without contrasting markings; obovate; slightly lobed or undulating; 3.5–4 mm long; 1.4–2 mm wide (tapering to 0.4–0.5 mm wide). Stamens 6; stamen filaments markedly unequal in length; stamen filaments glabrous. Anthers yellow; ovoid; 0.5–0.6 mm long. Ovary superior; carpels 2; syncarpous. Ovaries ovate; hairy. Ovary hairs straight. Styles 1; 0.5 mm long; straight. Stigmas per ovary 1. Placentation parietal. Ovules per ovary (16–)18–24. Fruit stalked; stalk 3–4 mm long; dry; a silique; ovoid; purple; 4–6 mm long; 2–2.5 mm wide; glabrous, or hairy; 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 0.2–0.5 mm long. Seeds (16–)18–24; 0.9–1.2 mm long; brown; surfaces verrucose.
Chromosome information. 2n = 48.
2n = 48. Heilborn (1927, Norway); Flovik (1940, Svalbard); Heilborn (1941, Norway, Greenland); Löve and Löve (1956, northern Europe); Böcher (1966a, Greenland); Knaben (1966, Norway); Knaben and Engelskjøn (1967, Norway); Mulligan and Cody (1968, North America); Mulligan (1970, North America); Engelskjøn (1979, Svalbard, Bear Island); Brochmann et al. (1993, Svalbard); Mulligan (2003).
Ploidy levels recorded 6x.
Ecology and habitat. Substrates: river terraces; imperfectly drained moist areas (raised river terraces); rocks, gravel; with low organic content; calcareous.
North American distribution. Nunavut Islands, continental Nunavut (?), northern Quebec, Labrador. Range in the Canadian Arctic Archipelago limited. Rare. Low Arctic. Arctic islands: Baffin.
Northern hemisphere distribution. Amphi-Atlantic. Northern Iceland, Northern Fennoscandian, KaninPechora, Svalbard Franz Joseph Land, Polar Ural Novaya Zemlya, Labrador Hudson Bay, West Greenland, East Greenland.
General notes. This taxon is closely related to D. arctogena, and intermediate plants are reported from Greenland (Böcher 1966a). The intermediates may represent the interbreeding of North Atlantic 'D. norvegica' and plants of 'D. arctogena' originally from Greenland and be parts of one polymorphic species. If this is so they may be best treated as subspecies. Russian authors identify Draba arctogena in Canadian and Far East collections. The Canadian materials of the D. norvegica group (including D. arctogena) need to be revised.
Plants morphologically similar to, and preliminarily identified with, D. norvegica have been repeatedly collected on Wrangel Island. A further study of this critical material is required (Petrovsky, personal communication, May 2002).
Illustrations. • Close-up of plant. Note comparatively small emarginate (notched) petals, and the fresh green leaves that lack true stellate hairs. Norway, Sor-Trondelag, Oppdal, Leirtjonnkollen Mountain. July, 1996. Photograph by R. Elven. • 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..