Flora of the Canadian Arctic Archipelago
Fabaceae (Leguminosae), Pea family.
Published in Just's Bot. Jahresber. 19: 543. 1903.
Type: Canada: Yukon: Lewes River, J. B. Tarleton 33b. Holotype: US. Isotypes: S, NY.
Synonymy. Aragallus varians Rydberg, Bull. New York Bot. Gard. 2: 176. 1901.
Oxytropis campestris (L.) DC. var. varians (Rydberg) Barneby, Proc. Calif. Acad. Sci. 27: 253. 1952.
Oxytropis varians (Rydberg) Hultén, Acta Univ. Lund., n. f., avd. 2, 43, 1: 1107. 1942. nom. superfl.
Aragallus gracilis A. Nelson, Erythea 7: 60. 1899.
Oxytropis campestris (L.) DC. subsp. gracilis (A. Nelson) Hultén, Ark. Bot., ser. 2, 7, 1: 79. 1968.
Oxytropis hyperborea A.E. Porsild, Sargentia 4: 53. 1943. Type: N.W.T., Mackenzie R. Delta, east branch, 68°55'N, A.E. Porsild 7033, 21 July 1934. Holotype: CAN. Isotypes GH, S, US.
Vegetative morphology. Plants 5–35 cm high; perennial herbs; caespitose. Taproot present. Ground level or underground stems absent. Caudex present (stout and freely branching). Aerial stems ascending (or spreading). Aerial stem trichomes appressed. Leaves mainly basal; alternate; marcescent. Stipules present; 8–10 mm long; 4–5 mm wide; not sheathing; white (or light brown, papery, with a few long hairs); hairy; villous (densely at the apex); apex acuminate (with conspicuous veins extending into the tips). Petioles 10–15 mm long; hairy; strigose. Petiole hairs longer than the diameter of the petiole; appressed; straight. Leaf blades compound. Blades 30–90 mm long, 8–25 mm wide, veins pinnate. Blade adaxial surface hairy, hairs pubescent (sometimes) or short-silky or long-silky, hairs simple, hairs sparse, hairs white, or translucent. Blade abaxial surface hairy, hairs villous or short-silky or long-silky, hairs very dense, hairs white, hairs straight or wavy, hairs appressed or spreading. Blade apices acute, or obtuse. Leaflet arrangement pinnate. Leaflets 9–19; 3–10 mm long (conspicuously variable in this charcteristic); 1–2.5(–3) mm wide; oblong, or ovate; veins inconspicuous.
Reproductive morphology. Flowering stems two or more per plant; without leaves. Flowering stems hairy. Flowering stems strigose. Flowering stem hairs simple (pointing towards the flower); shorter than the diameter of the flowering stem, or longer than the diameter of the flowering stem; black and white or translucent (predominantly). Inflorescences racemose; dense; 1–2(–6) cm long; 15–25 mm wide; not elongating as the fruit matures. Pedicels absent. Floral scales hairy all over (with mainly white hairs). Flowers per inflorescence 3–12; medium-sized; bilaterally symmetrical (zygomorphic). Sepals conventional; 5; fused; 6–7 mm wide; black (because of copious black hairs). Calyx tubular (with deltoid teeth one third to one quarter of the length of the tube); 5-lobed; hairy (densely so with mixed short black and long white hairs). Calyx hairs villous; non-glandular; white or translucent and black. Calyx teeth equal or nearly so; 1.5–2 mm long. Petals conventional; both free and fused; 5; yellow (pale or fading light brown); with contrasting markings (colour differences that serve as guidelines to visiting insects); unlobed (4 petals), or slightly lobed or undulating (banner petal); 13–17 mm long. Corolla papilionaceous; keel with a pointed tip. Stamens 10; stamen filaments all equal in length (slightly unequal). Anther filaments 9 fused into a tube, plus 1 free. Nectaries present. Ovary superior; monomerous. Stigmas per ovary 1. Ovules per ovary 15–25. Fruit sessile; with calyx persisting; dry; a legume; ovoid, or elongate-cylindrical (with a prominent beak); yellowish; 10–15 mm long; 3.5–4.5 mm wide; hairy (with black and white hairs); not distinctly flattened; dehiscent; opening at the apex and partially or fully down one side. Legume unilocular; valves straight. Styles persisting but not modified. Seeds 6–10; 1–2 mm long (i.e., the longest dimension); brown; surfaces smooth.
Chromosome information. 2n = 16, or 32, or 36, or 48, or 50, or 64, or 96.
2n (2x) =16. Dawe and Murray (1981, central Alaska, two counts, 'varians');
2n (4x) = 32. Dawe and Murray (1981b, central Alaska, 'varians');
2n = 36. Knaben (1968, central Alaska, 'gracilis');
2n (6x) = 48. Taylor and Taylor (1977, western Canada, 'gracilis'); Elisens (1978, central and southern Alaska);
2n = about 60. Johnson and Packer (1968, northwestern Alaska, 'gracilis', acc. to Yurtsev most probably belonging to O. hyperborea);
2n (8x) = 64. Löve and Löve (1982a, central Canada, 'gracilis');
2n (12x) = 96. Elisens (1978, central and northern Alaska); Dawe and Murray (1981b, central and northern Alaska, 'varians'); Löve and Löve (1982a, Arctic Canada, 'varians'.
Ploidy levels recorded 2x/4x/6x/8x/12x.
Ecology and habitat. Substrates: rocks, gravel; calcareous (sandy and gravelly sites).
North American distribution. Range in the Canadian Arctic Archipelago limited (the arctic coast of the Yukon, N.W. Mackenzie District and westernmost islands of the Arctic Archipelago). Rare. Low Arctic. Arctic islands: Banks, Victoria.
General notes. Elisens and Packer (1980) considered the O. campestris complex in northwestern North America a polyploid series comprising at least seven morphologically and geographically distinct taxa. They recognised O. varians as having hexaploid and decaploid representatives but did not attempt to divide the taxa, as no differences were observed between them with the exception of guard cell size. Elven (personal communication, 2005) noted that the following ploidy levels are reported within O. varians: 2x, 4x, 6x, 8x, 12x, all of them on quite reliably identified material. This is obviously a complex 'species'.
Oxytropis hyperborea is now synonymised with O. varians or, if it is considered to be a subspecies or variety, with O. campestris subsp./var. varians by almost all current North American authors, e.g., Cody (1996), Gillett et al. (1999 onwards).
Illustrations. • Habitat. Plant growing on sandy beach. Manitoba, Hudson Bay, Churchill. 14 July, 1972. J.M. Gillett 15744. • Close-up of plant. Plant growing with willow on tundra. Banks Island, Sachs Harbour. 29 July, 1981. J.M. Gillett 18927. CAN. • Close-up of plant. Plant procumbent on tundra. N.W.T., Banks Island, Sachs Harbour. 29 July, 1981. J.M. Gillett 18939. CAN. • Close-up of flower. Note calyx lobes are blackish from dense hairs, and the teeth are lanceolate. N.W.T., Banks Island, Sachs Harbour. 29 July, 1981. J.M. Gillett 18939. 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..