Mima Mounds Natural Area Preserve, Thurston Co., WA, 28.6.2000, Photo © Markku Savela
Prairie lupine (Lupinus lepidus var.lepidus)
Prairie lupine is a small
perennial lupine of diverse form and habitat in the
There are five known varieties of Lupinus lepidus. Variety lepidus is best described by itís extended racemes growing above the longest leaves and the length of itís flowers between 11-13mm long.1
Prairie lupine (var. lepidus)
is distributed in the lowlands west of the
Prairie lupine may be found in lowland areas growing in arid climates (40-65 inches of annual precipitation) at elevations below 600 feet.
Prairie lupine occurs in lowlands on gravelly to sandy soils, often on flat or mounded plains of recessional glacial outwash.4
Lupinus lepidus var. lobbii was the first plant to colonize the devastated slopes of Mount St. Helens† Seeds are probably dispersed by explosive dehiscence (bursting of the seed pods) and rolling, or by erosion and deposition.
Species associated with
Prairie lupine include houndstongue hawkweed (Hieracium cynoglossoides), cutleaf microseris (Microseris laciniata), spike
goldenrod (Solidago spathulata),
white-top aster (Aster curtus), and slender
cinquefoil (Potentilla gracilis).
Long-stolon sedge (Carex pensylvania), field woodruch (Luzula campestris),
Collect as seed
†Hairy pods range from 10-20 cm long with 2-12 seeds.2
Seed can be hand collected from June to August, but collecting is slow due to the small size of the plant. Seeds should be dried in the pods in paper bags. Remove the seeds from the pods by hand thresh and screen.7
Cuttings can also be taken from the side shoots of hardened stems in the spring
Seed requires scarification. Shake in jar half-filled with coarse sand, scarify with sand paper7, or rock tumbler for two hours.
After scarification, soak in hot water until the water has cooled (approximately 3 hours). Seeds that sink have absorbed enough water to be sown. Those that do not sink should be dried, scarified and soaked in water again.
Lupine seeds have a hard seed coat, and because related lupine species are known to have long-lived dormant seed banks (e.g. L. arboreus was germinated in a seed bank study after 45 years), it is likely that prairie lupine seeds are also long-lived and can be stored at low moisture and temperature levels for several years.
Store air-dried seed under cool, dry conditions. Protect from small mammals and rodents.
Plant seeds singularly in long narrow pots (at least 3Ē) and transplant from pots into the field within the same year (about 8 months).
Lupine seedlings have very sensitive roots and suffer from root damage when handled excessively. Sensitivity to the root system is especially needed when transplanting from nursery containers into the field.
Sow lupine seeds in potting soil mixture of coarse and fine particles. Like other legumes prairie lupine has root nodules which house bacteria which fix nitrogen, providing fertilizer for the plant. Potting soil can be inoculated by mixing a small amount of soil from the seed collection site in the potting mix. Use low nitrogen fertilizer and no humus.
1-2 foot centers
Seedlings develop very long roots and should be transplanted with sensitivity restricting damage during transplanting.
Mist lightly, daily with restricted water.
Rate of growth
Rate of growth is variable. First year growth is limited due to resources needed to develop large root systems, particularly in rocky soils.
Data compiled by Amy Lambert,
 Slichter, Paul, website: http://ghs.gresham.k12.or.us/science/ps/nature/gorge/5petal/pea/prairie.htm
 Gilkey and Dennis 1980. Handbook of Northwest Plants.
 Hitchcock,C.L., and A. Cronquist. 1973.Flora of the
 Chapell, Chris 2002. Unpublished data Puget-Georgia-Willamette Ecoregion plant data
 Goroff, Iza, North American Rock Garden Society website: http://www.nargs.org/potm/potm_jan01.html
 website: http://sacramento.fws.gov/es/plant_spp_accts/clover_lupine.htm, prepared by Endangered Species Division, Sacramento Fish & Wildlife Office, U.S. Fish & Wildlife Service
 Foster, C.O. 1997. Plants-a-Plenty: How to Multiply
Outdoor and Indoor Plants Through Cuttings, Crown and Root Divisions, Grafting,
Layering and Seeds.