Range

Silky lupine occurs east of the Cascade Range from British Columbia south to California and Arizona and east to Alberta, Montana, South Dakota, Colorado, and New Mexico. (Hitchcock and Cronquist 1973)

Climate, elevation

Silky lupine has been found to 10,000 feet (3,030 m) elevation in Colorado and Utah (FEIS database)

Local occurrence

East of the Cascades, silky lupine occurs as a significant component of the herbaceous layer in ponderosa pine savannas, shrub-steppe, and grassland communities. (FEIS database)

Habitat preferences

Silky lupine occurs in a range of habitats including grasslands, sagebrush, mountain brush, and aspen and conifer forests. Silky lupine is found on dry, rocky sites on gentle to steep slopes and in open woods. (FEIS database)

Plant strategy type/successional stage

Seral species. Tolerant of partial shade but prefers full sun. Occurs in open, climax ponderosa pine systems throughout its range and in openings within late-seral Douglas-fir forests in Idaho. (FEIS database)

Associated species

Some species commonly associated with silky lupine include Gambel oak (Quercus gambelii), common snowberry (Symphoricarpos albus), ninebark (Physocarpus malvaceus), serviceberry (Amelanchier spp.), mountain-mahogany (Cercocarpus spp.), arrowleaf balsamroot (Balsamorhiza sagittata), western yarrow (Achillea millefolium), heartleaf arnica (Arnica cordifolia), pinegrass (Calamagrostis rubescens), bluebunch wheatgrass (Pseudoroegneria spicata), Sandberg bluegrass (Poa secunda), Idaho fescue (Festuca idahoensis), prairie junegrass (Koeleria cristata), and sedges (Carex spp.). (FEIS database)

May be collected as:

Seed

Collection restrictions or guidelines

Collect seedpods when they turn tan, before dehiscence. Pods are generally mature from July into August depending upon location. (FEIS database; Hosokawa, et al. 2001)

Seed germination

Silky lupine seeds are protected by a hard seed coat and need germination pretreatments of scarification and stratification. One method for achieving germinable seeds is as follows:

Seeds are placed in a hot water scarification bath and allowed to cool overnight to imbibe. Seeds are wrapped in moist paper towels and placed under refrigeration at 3 degrees C for a 30-day stratification. (Hosokawa, et al. 2001)

Seed life (can be stored, short shelf-life, long shelf-life)

Seeds can remain viable from 20 to 60 years in sealed containers at 3 to 5 C. (Hosokawa, et al. 2001)

Recommended seed storage conditions

Dry seeds in sealed containers stored at 3 to 5 C.

Propagation recommendations

Seed

Soil or medium requirements

Seeds should be inoculated with Rhizobium specific to Lupinus spp. and can be planted for container production in a soilless mix of peat, perlite, vermiculite and sand with a controlled release fertilizer. (Hosokawa, et al. 2001)

Silky lupine grows best on sites with dry, sandy, loamy, sandy-loam, and clayey-loam soils. (FEIS database)

Installation form

Silky lupine does not transplant well, so direct seeding after inoculation with Rhizobium is recommended. If container grown seedlings are used, they should be transplanted the first year if possible and can be installed in the spring or fall. (Hosokawa, et al. 2001)

Recommended planting density

No data found.

Care requirements after installed

Water regularly at least through first growing season.

Normal rate of growth or spread; lifespan

Container grown seedlings are large enough for transplanting after 1 growing season.

Sources cited

FEIS database: Accessed on 5/9/03, www.fs.fed.us/database/feis/plants/forb/lupser

Franklin, J. F. and C. T. Dyrness. 1973. Natural Vegetation of Oregon and Washington. Oregon State University Press, Corvallis

Hitchcock, C. L. and A. Cronquist. 1973. Flora of the Pacific Northwest: an illustrated manual. University of Washington Press, Seattle.

Hosokawa, J., D. Wick, and T. Luna. 2001. Propagation protocol for production of container Lupinus sericeus Pursh. plants (172 ml conetainers); Glacier National Park, West Glacier, Montana. In: Native Plant Network. URL: http://www.nativeplantnetwork.org (accessed 9 May 2003). Moscow (ID): University of Idaho, College of Natural Resources, Forest Research Nursery.

Data compiled by Anne G. Andreu, 5/9/2003