Flora of the Canadian Arctic Archipelago
English: Arctic wallflower,
Brassicaceae (Cruciferae), Draba family.
Published in Rhodora 27: 171. 1925.
Type: Described from Canada: Melville Island.
Synonymy. Cheiranthus pallasii Pursh, Fl. Amer. Sept. 2: 436. 1814.
Cheiranthus pygmaeus Adams, Mem. Soc. Nat. Mosc. Y. 114. 1817.
Erysimum pallasii f. humilum (Tolmatchew) Polunin, Bull. Natl. Mus. Canada 94 (Biol. Ser. 24): 248. 1940.
Hesperis hookeri Ledeb. Fl. Ross. 1: 174. 1841.
Vegetative morphology. Plants 7–25 cm high; biennial herbs, or perennial herbs (short-lived); caespitose. Taproot present. Ground level or underground stems absent. Caudex present (usually swollen, but rarely branched). Aerial stems erect. Leaves mainly basal; alternate; marcescent. Petioles absent. Leaf blades simple. Leaf blade bases attenuate. Leaves not grass-like. Blades (20–)30–50(–70) mm long, 2–3 mm wide, spatulate. Blade adaxial surface hairy, hairs branched (bifurcate). Blade abaxial surface glabrous. Blades not lobed. Blade margins dentate (repand dentate) or entire, glabrous, with teeth toward the apex. Hydathodes absent. Blade apices acute.
Reproductive morphology. Flowering stems two or more per plant; without leaves. Inflorescences racemose; elongating as the fruit matures. Flowers per inflorescence 8–25 (to 50 or more); medium-sized; radially symmetrical (actinomorphic). Sepals conventional; 4; free; 7.5–8.5 mm wide; green and purple; herbaceous. Calyx hairy. Calyx hairs white or translucent. Petals conventional; free; 4; green, or purple (more usually); without contrasting markings; obovate (with a long claw); unlobed, or slightly lobed or undulating; 12–15 mm long. Stamens 6; stamen filaments markedly unequal in length; stamen filaments glabrous; free of the corolla. Anthers yellow; 1.8–2.2 mm long. Ovary superior; carpels 2; syncarpous. Ovaries hairy. Ovary hairs straight. Styles 1; 0.4–0.6 mm long. Stigmas per ovary 1. Placentation parietal. Ovules per ovary 25–35. Fruit stalk 10–16 mm long; dry; a silique; elongate-cylindrical (somewhat curved); purple; 60–100 mm long; 2–3 mm wide; hairy; 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 1.2–1.7 mm long. Seeds 25–35; 2.2–2.5 mm long; brown; surfaces verrucose.
Chromosome information. 2n = 24, or 28, or 36, or 42.
2n (4x, x = 6) = 24. Packer (1964, northwestern Canada, 2n = about 24); Mulligan (1966b, Canada); Mosquin and Hayley (1966, northern Canada); Krogulevich (1976a, northern Siberia); Berkutenko and Gurzenkov (1976, northeastern Asia); Yurtsev and Zhukova (1982, northern Siberia); Zhukova and Petrovsky (1984, northern and northeastern Asia; Berkutenko et al. (1984, northeastern Asia); Mulligan (2003);
2n = about 28. Holmen (1952, Greenland); Mulligan and Porsild (1969, Yukon); Mulligan (2003);
2n (6x, x = 6) = 36. Rollins (1966, Alaska); Zhukova (1966, 1968, northeastern Asia); Zhukova and Tikhonova (1971, 1973, Chukotka); Zhukova et al. (1973, 1977, northeastern Asia); Petrovsky and Zhukova (1981, Wrangel Island); Zhukova and Petrovsky (1984, northeastern Asia); Mulligan (2003);
2n = about 42. Hedberg (1967, Alaska); Krogulevich (1976a, northern Siberia).
Ploidy levels recorded 4x/6x.
Ecology and habitat. Substrates: river terraces, slopes, ridges; dry, moderately well-drained areas; gravel, sand, clay, till (often scree); with low organic content; calcareous, or nitrophilous. The flowers are very fragrant.
North American distribution. Alaska, Yukon, Northwest Territories Islands, continental Northwest Territories, Nunavut Islands, continental Nunavut. Range in the Canadian Arctic Archipelago widespread. Common. Arctic. Arctic islands: Baffin (Bylot), Ellesmere, Axel Heiberg, Parry islands (Melville), Banks, Victoria.
Northern hemisphere distribution. Circumpolar (almost, occurring from northern Greenland westward to North European Russia, with a gap in northern Europe), or circumboreal. Polar Ural Novaya Zemlya, Taimyr Severnaya Zemlya, Kharaulakh, YanaKolyma, West Chukotka, South Chukotka (?), East Chukotka, West Alaska, North Alaska Yukon, Central Canada, Ellesmere Land Peary Land.
General notes. This species varies considerably in size depending upon its habitat.
Erysimum pallasii is often found near bird-nesting areas, where the soil is rich in calcium and nitrogenous compounds. It is a biennial or short-lived perennial, and flowers only once in its lifetime (Burt 2000).
Illustrations. • Habitat. Isolated plants with purple flowers growing in sandy gravel near the top of a pingo. N.W.T., Banks Island, Aulavik National Park. 11 July, 1999. Aiken 99–055. CAN. • Close-up of purple-pink flowers. Flowers with four purple-pink petals. Central upper flower has the inner ring of four anthers at pre-anthesis, and no evidence of the second whorl of two anthers; right-hand flower shows six anthers, that is, the second whorl of anthers has developed. N.W.T., Banks Island, Aulavik National Park. 11 July, 1999. Aiken 99–055. CAN. • Close-up of developing siliques. Note siliques much longer than they are wide and the two-lobed stigma at the tip. Note the petal margins are uniform, as oppose to undulating, a distinction from in Parrya. N.W.T., Banks Island, Aulavik National Park. 11 July, 1999. Aiken 99–055. CAN. • Close-up of plant setting seeds. Plant with purple flowers in which long narrow siliques are developing. Fruit margins are smooth, those of Parrya undulate. Note the two-lobed sessile stigma. N.W.T., Banks Island, Aulavik National Park. 11 July, 1999. Susan Aiken 99–055. CAN. Scale bar in cm. • Close-up of fruiting plant. Fruiting plants to 7 cm tall. Fruits are much longer than wide (fruits of Parrya are shorter and broader), and uniformly wide from top to bottom (fruits of Parrya are undulating). Nunavut, Victoria Island, Cambridge Bay. 28 July, 1997. L.L. Consaul 1132 and L.J. Gillespie. CAN. • 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..