Lupinus arcticus
Proc. Amer. Acad. Arts 8: 526. 1873.
Herbs, perennial, 1–4 dm, hairs thinly appressed silky-sericeous, or few to many and spreading; caudex superficial, divisions closely tufted. Cotyledons deciduous, petiolate. Stems ascending to erect, hollow, tufted, branched at crown. Leaves mostly basal with a few cauline proximal to inflorescences; stipules 8–10 mm; petiole 5–19 cm; leaflets 6–10, blades 13–90 × 10–15 mm, abaxial surface thinly strigose, adaxial surface glabrous. Peduncles 4–8.5 cm; bracts caducous to tardily deciduous, 8–14 mm. Racemes 5–8(–15 in fruit) cm; flowers spirally arranged or in 3–7 whorls. Pedicels 4–6 mm. Flowers 14–19(–21) mm; calyx bulge or spur 0–1 mm, abaxial lobe 6–11 mm, entire or faintly notched at tip, adaxial lobe ± gibbous basally, adaxial lobe teeth with slight notch at tip, 4–8 mm; corolla usually blue to purplish, sometimes pink, rarely white, banner spot white or yellow, sometimes becoming purple, banner glabrous abaxially, lower keel margins densely ciliate near claw or glabrous or sparsely ciliate towards tip, adaxial margin glabrous or sparsely ciliate towards tips. Legumes 2–4.3 cm, silky-pilose. Seeds 5–8, mottled. 2n = 48.
Phenology: Flowering Jun–Aug.
Habitat: Well-drained hummocks of alpine and arctic tundra, moist to mesic meadows, gravel bars, clearings, roadsides, thickets, open forests.
Elevation: 0–2000 m.
Distribution
B.C., N.W.T., Nunavut, Yukon, Alaska.
Discussion
The relationship between Lupinus arcticus and L. latifolius is unclear. They may be distinguished by the presence of proximal keel ciliation in L. latifolius, and basal rather than cauline leaves dominating in L. arcticus.
Selected References
None.