Hedysarum boreale subsp. mackenziei
Great Basin Naturalist 28: 152. 1968. (as mackenzii)
Stems usually unbranched distally, 1.5–5(–6) dm. Leaves 3–12(–14) cm; stipules usually stramineous; leaflets 9–15, blades 10–40 × 3–14 mm, surfaces pubescent abaxially, glabrous adaxially. Racemes 5–20-flowered, 2–10(–15) cm. Flowers: corolla usually red-purple (fading dark purple), sometimes pink, rarely white, (14–)18–22(–26) mm. Loments: segments 3–8, margins and areolae often black-pigmented, 4.5–8 × 4–5.5 mm. 2n = 16.
Phenology: Flowering summer.
Habitat: Stream banks, gravel bars, sea beach ridges, terraces, mud flats, lacustrine deposits in willow, aspen, spruce, and along ridges in alpine tundra communities.
Elevation: 0–1900(–2200) m.
Distribution
Alta., B.C., Man., Nfld. and Labr. (Nfld.), N.W.T., Nunavut, Ont., Que., Sask., Yukon, Alaska, Oreg., Wash.
Discussion
Subspecies mackenziei is the common phase of the species throughout northern North America; it is especially common on gravel bars where it serves as an ecological pioneer. In Alberta and southern British Columbia, it is somewhat transitional with subsp. boreale. The plants at higher elevations in the mountains of northern British Columbia, Yukon, and Alaska are often very short, but maintain the large, dark flowers of the subspecies.
Selected References
None.