Oxytropis podocarpa A. Gray
Fabaceae (Leguminosae), pea family.
Proc. Amer. Acad. 6: 234. 1864.
Type: Type locality: "Labrador, Arctic regions, and Rocky Mountains, lat. 49°." Lectotype selected by Fernald (1928), Labrador, Schweinitz, s.n. (Welsh 1995).
Oxytropis podocarpa var. inflata (Hooker) Boivin, Naturalisteastern Canadaad. 94: 78. 1967. Oxytropis arctica var. inflata Hooker, Fl. Bor.-Amer. 1: 146. 1831. Type: "Highest summits of the Rocky Mountains., Drummond s.n.," Holotype K (paratype of Oxytropis podocarpa, Welsh 1995).
Vegetative morphology. Plants perennial herbs; 2–6 cm high; cushion-like, but not as dense as O. nigrescens var. uniflora, with leaves and semi-prostrate spreading branches. Taproot present. Caudex present. Aerial stems erect; not visible in the dense cushions. Leaves in a basal tuft; alternate; compound; marcescent. Stipules present; scale-like; sheathing (most readily seeNorth Americaong the previous season's growth); brown (pale), or white. Petioles 5–12 mm long. Blades 7–12 mm long; 6–9 mm wide. Blades veins pinnate. Blades adaxial surface hairy. Blades adaxial surface hairs pilose, or long-silky; simple, unbranched; sparse; white and translucent. Blades abaxial surface hairy. Blades abaxial surface hairs very dense. Blades abaxial surface hairs long-silky. Blades abaxial surface hairs white, or translucent hairs; straight; appressed. Leaflet arrangement pinnate. Leaflets (5–)7–13; 2–5 mm long; linear.
Reproductive morphology. Flowering stems present. Flowering stems without leaves; hairy. Flowers solitary (rarely), or in inflorescences (of two flowers). Inflorescence racemose (when two flowers are present). Flowers medium-sized, 5–15 mm in diameter or length; zygomorphic. Calyx sepals 5; fused. Calyx brown (bluish hairy); tubular; 5-lobed; hairy. Petals both free and fused; 5; purple, or blue (violet); with contrasting markings (insect guide lines and colour gradation from intense colour at the tips of the petals to pale at the bases); unlobed (four petals), or shallowly lobed (banner petal); 11–16 mm long. Corolla papilionaceous. Corolla keel with a pointed tip. Stamens 10; filaments all equal in length (or almost). Nectaries present. Gynoecia superior. Carpels monomerous. Ovules 20–28. Fruit stalked. Fruit with calyx persisting; dry; a legume (on a stalk within the calyx); ovoid; dehiscent (from the tip of the legume). Fruit 12–20 mm long (? to 30 mm long, Porsild, 1964); 6–10 mm wide; black; hairy. Legume unilocular. Styles may persist until dehiscence but are not modified. Seeds 16–24; 1.5–2 mm long (i.e., the longest dimension); black, or brown; with surfaces smooth.
Chromosome information. 2n = 16. 16 (2x). - Ledingham (1960).
Distribution. Low arctic (A rare species of peculiar disrupted range. Known thus far from the Rocky mountains, northern Labrador and southern Baffin Island). Rare. Arctic Islands: Baffin (Iqaluit, Amajuak Bay), Southampton.
Ecology and habitat. Substrates: hummocks, tundra; imperfectly drained moist areas, or moderately well drained areas; acidic, or calcareous; gravel, sand (ridges).
Taxon as an environmental indicator. This is a southern species, with the most northern record being from Southampton Island, Salmon Pond, 64°12'N.
Notes. Porsild (1964) mapped records for Kimmirut and Cape Dorset. These have not been confirmed.
Illustrations. • Herbarium specimen. Flowers with blue petals and blackish calyx. Note the long tap root with many shoots arising from the caudex or root crown. Nunavut, Baffin Island, Iqaluit, 14 July, 1953, V.C. Wynne-Edwards 9310. CAN 223777. • Fruiting plant. Fruiting plant with pods about 1 cm long splitting from the apex. J.M. Gillett. 820495. • 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).
