Lupinus kuschei Eastw. Synonyms: sericeus var. kuschei

Global Distribution: Endemic to Alaska, Yukon, and northern British Columbia.

Alaska Distribution: Intermontane Boreal, Alaska Range Transition, Coastal Mountains Transition.

Ecoregions Occupied: Copper River Basin, Tanana-Kuskokwim Lowlands, Kluane Ranges, Yukon-Tanana Uplands; disjunct in Kobuk Ridges and Valleys, Yukon River Lowlands.

Conservation Status: S2 G3G4; BLM Watch.

Description24, 25, 124

Racemes 3 to 10 cm long

4 mm

Corolla 10 to 13 mm long

5 to 9 leaflets per leaf Leaflets silky villous on both sides 1 cm 2 cm

Long, branched caudex Petioles 2 or more times longer than the leaf diameter

Illustration by Jeanne R. Janish, courtesy of University of Washington Press 159

Lupinus kuschei

General: Perennial herb from long, branched caudex; entire except corollas silky-villous; stems decumbent to erect, 15 to 50 cm tall.

Leaves: Petioles of basal leaves 4 to 15 cm long; leaves alternate, palmately compound with 5 to 9 leaflets per leaf; leaflets elliptic to oblanceolate, 1.5 to 5 cm long.

Flowers: dense, stalked, 3 to 10 cm long; calyxes two-lipped, upper lip 4 to 6 mm long, lower lip slender and 5 to 7 mm long; corollas blue to purple, 10 to 13 mm long.

Fruits: Pods 2 to 3 cm long; 4 to 6.

© Matthew L. Carlson 2012

Ecology

Elevation: Known from 60 to 880 m in Alaska.

Landform: Active sand areas including dunes, blowouts, sand sheets, and open sand; river terraces, river bars, floodplains; roadsides.49

Soil Type: Usually in sand; also in silt and cobbles.

Moisture regime: Moist to dry.

160

Lupinus kuschei

Slope: Flat to sloping.

Aspect: No particular aspect.

Vegetation type: Sparsely vegetated, open poplar floodplains, scattered willow shrub.

Associated species: Calamagrostis purpurascens, Dryas drummondii, Festuca rubra, Hedysarum mackenziei, Oxytropis campestris, Oxytropis deflexa, Populus balsamifera, Solidago simplex var. simplex.

Longevity: Perennial, longevity unknown.

Phenology: Flowering early June, probably sooner; fruiting early July.

Population estimate: There are 15 known occurrences in Alaska; population sizes range from a few individuals to locally common.

Reproductive biology: is long lived; Lupinus kuschei frequently colonizes new areas and often benefits from natural disturbance.124

Herbivory: In Yukon, have been found partially browsed, likely by horses, and are known to be consumed by Canada Geese.125

Similar Species24, 25, 124

Lupinus kuschei can be confused with Lupinus nootkatensis in the southern portion of its range in Alaska and with Lupinus arcticus throughout its range in Alaska. The table below describes the differences in morphology and habitat between these similar species.

Basal Species Habitat Leaflets Corolla Petioles Petioles 2 Sandy areas or more Silky- including times 3 to 10 to Lupinus villous on dunes, river longer than 10 cm 13 mm kuschei both terraces, the long long surfaces floodplains diameter of the leaf Gravel bars, Petioles Glabrous meadows, longer than 5 to 14 to Lupinus above, open forests, the 15 cm 20 mm arcticus pubescent alpine slopes, diameter of long long below heath the leaf Meadows, Petioles as Usually forest 5 to 15 to Lupinus long as the glabrous openings, 35 cm 21 mm nootkatensis diameter of above, soft- alpine slopes, long long the leaf hairy below gravel bars

161

Lupinus kuschei

© Forrest Baldwin 1999

© Matthew L. Carlson 2012

162