Lesquerella arctica (Wormsk.) S. Wats.
Arctic Bladderpod.
Brassicaceae (Cruciferae), Draba family.
Proc. Amer. Acad. Arts. 23: 254. 1888
Alyssum arcticum Wormsk. ex Hornem., Fl. Dan. 9, 26: 3, t. 1520. 1818.
Vesicaria arctica (Wormsk.) Richardson
Lesquerella arctica
var. purshii S. Wats.
Lesquerella purshii (S. Wats.)
Fernald
Lesquerella arctica subsp. purshii (S. Wats.) A. Pors.
Vesicaria arctica var. leiocarpa Trautv.
Vesicaria
leiocarpa (Trautv.) N. Busch
Lesquerella arctica var.
scammanae Rollins
Vegetative morphology. Plants perennial herbs; 6–12 cm high; with a strong taproot, and basal spathulate slivery grey leaves. Taproot present. Caudex present (woody, branched or unbranched). Aerial stems erect, or prostrate; densely hairy. Leaves in a basal tuft; alternate; simple; existing for a single season or less. Petioles absent. Leaf blade bases attenuate. Blades 1.5–3 mm long; 3–7 mm wide. Blades herbaceous; spatulate; appearing single-veined. Blades adaxial surface hairy. Blades adaxial surface hairs a mixture of white and yellow hairs. Blades abaxial surface with sessile glands; hairy. Blade margins entire; glabrous. Conspicuous hydathodes absent. Leaf apices acute, or obtuse.
Reproductive morphology. Flowering stems present. Flowering stems shorter than the leaves; with leaves; hairy. Inflorescence racemose; main axis hairy. Pedicels present. Flowers per inflorescence 3–8; small, less than 5 mm in diameter or length; actinomorphic. Calyx sepals 4; free; 4–4.5 mm long. Calyx green; herbaceous; hairy. Calyx hairs white or translucent. Petals free; longer than the calyx; 4; yellow; without contrasting markings; obovate; shallowly lobed; 4.5–6 mm long. Flowers bisexual. Stamens 6; filaments markedly unequal in length; free of the corolla; filaments glabrous. Anthers yellow; 1–1.2 mm long. Gynoecia superior. Carpels syncarpous; 2. Ovaries glabrous. Styles 1; 1–1.3 mm long. Stigmas per style 1. Placentation parietal. Ovules 6–8. Fruit stalk 6–10 mm long. Fruit without calyx persisting; dry; a silique; spherical; dehiscent. Fruit 4–6 mm long; 4–6 mm wide; yellowish and purple; glabrous. Styles remaining straight; persisting in fruit 1.7–2.2 mm long. Seeds 6–8; 1.8–2.2 mm long; brown; with surfaces verrucose.
Chromosome information. 2n = 60. Böcher and Larsen (1950 Greenland); Holmen (1952 Greenland); Jørgensen et al. (1958 Greenland); Zhukova (1965b Wrangel Island); Knaben (1968 Alaska); Mulligan and Porsild (1969a Yukon); Krogulevich (1976 northern Siberia); Dawe and Murray (1981a northern Alaska, two counts); Löve and Löve (1982 arctic Canada); Yurtsev and Zhukova (1982 northern Siberia); Zhukova and Petrovsky (1984 north and north eastern Asia); Dalgaard (1989 western Greenland). Supposed basic chromosome number of family X=5–12. Ploidy levels recorded 12x.
Distribution. Northern hemisphere distribution: amphi-Beringian; Greenland, Canada, United States, Eurasia. Yukon, Northwest Territories Islands, Continental Northwest Territories, Nunavut Islands, Continental Nunavut, Northern Québec. Arctic, or alpine. Range in the Canadian Arctic Archipelago widespread. Common. Arctic Islands: Baffin, Ellesmere, Axel Heiberg, Banks, Victoria, Southampton (Boothia and Melville Peninsula).
Ecology and habitat. Substrates: river terraces, slopes, ridges; dry; calcareous; rocks, gravel, sand, clay; with low organic content. Habitats: Many of the leaves of this species are slightly cupped, with a single blunt tooth on each side. The leaves are covered by unusual stellate hairs (several hairs arising from a single spot on the leaf, diverging to form a star), easily visible with a hand lens. The yellow flowers are borne in loose racemes at the end of several widely-diverging flower stalks. The siliques (seedpods) are globular, resembling tiny balls each with the remains of the style at the tip, hence the common name of bladderpod.
Notes. Larger specimens of this species were previously recognised as var. scammanae but Rollins (1993) has reduced this taxon to synonymy as size seems to be a reflection of the habitat.
Illustrations. • Plant habitat. Plant growing on dry calcareous tundra near John Richardson Bay, Ellesmere Island, Nunavut, 80°20'N, 71°21'W. Aiken 98–003. Photograph by Mollie MacCormac. • Plant habitat. Plant growing on dry calcareous tundra near John Richardson Bay, Ellesmere Island, Nunavut, 80°20'N, 71°21'W. Aiken 98–052. CAN. Photograph by Mollie MacCormac. • Plant habit. Plant growing on dry stony clay, N.W.T. Banks Island, Sachs Harbour. 24 July 1981, J.M. Gillett 18796. CAN. • Plant habit. Plant growing on dry calcareous tundra near John Richardson Bay, Ellesmere Island, Nunavut, 80°20'N, 71°21'W. Aiken 98–003. Photograph by Mollie MacCormac. • Close-up of flower. Plant growing on dry calcareous tundra near John Richardson Bay, Ellesmere Island, Nunavut, 80°20'N, 71°21'W. Aiken 98–052. Photograph by Mollie MacCormac. • Close-up of developing fruits. Remains of flowers showing sepals shorter and narrower than the petals, but both yellow, and developing globose fruits. Aiken 98–003. CAN. Photograph by Mollie MacCormac. • Close-up of developing fruit. Remains of flowers showing sepals shorter and narrower than the petals, but both yellow, and developing globose fruits with short styles and a capitate stigma. Aiken 98–003. CAN. Photograph by Mollie MacCormac. • Plant in fruit. Plant with globose fruits growing on dry stony clay, N.W.T., Banks Island, Sachs Harbour, 24 July 1981, J.M. Gillett 18796. CAN. • Arctic Island Distribution.
Cite this publication as: ‘S.G. Aiken, M.J. Dallwitz, L.L. Consaul, C.L. McJannet, L.J. Gillespie, R.L. Boles, G.W. Argus, J.M. Gillett, P.J. Scott, R. Elven, M.C. LeBlanc, A.K. Brysting and H. Solstad. 1999 onwards. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 29th April 2003. http://www.mun.ca/biology/delta/arcticf/’. Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993, 1995, 2000) should also be cited (see References).
