Big-leaf lupine
(Lupinus polyphyllus)
Herbaceous perennial that is 2-4’ tall. Big-leaf lupine is native to the western United States and Canada, but not Wisconsin. Commonly grown in cultivation and used to create hybrids in the plant trade.
Overview
Other names for this plant include:- Common names: Russel lupine, giant lupine, garden lupine, Washington lupine.
- Hybridizes with sundial lupine (L. perennis) with the resulting plants being unsuitable hosts for the Karner Blue Butterfly larvae.
Classification in Wisconsin: Not regulated.
Identification
Leaves: Alternate and palmate. Lower leaves have 12-18 leaflets that are hairy on the underside and have long petioles.
Flowers: Blue-violet, pink or white, pea-like flowers are borne on 6-18” long racemes. Blooms during midsummer and flowers open from the bottom.
Fruits & Seeds: Oblong, flattened seedpods that are hairy and contain 3-9 seeds per pod.
Roots: Taproot.
Similar species: Native or sundial lupine (L. perennis) has 7-11 leaflets and has a raceme that is less dense. The flowers are only blue-violet in color.
Control
Mechanical: Mow during flowering stage or cut root with shovel 1-2” below the soil. Monitor for new growth for several seasons.
Chemical: For larger infestations, foliar spray with clopyralid before seed set.
Resources
Sources for content:- Czarapata, Elizabeth; Invasive Plants of the Upper Midwest: an illustrated guide to their identification and control. University of Wisconsin Press. 2005. Pg. 138
- Great Lakes Indian Fish and Wildlife Commission: Bigleaf Lupine (Lupinus polyphyllus ssp. polyphyllus) [exit DNR]. Last updated January 2006.
- Cullina, William. 2000. The New England Wild Flower Society guide to growing and propagating wildflowers of the United States and Canada; pg 140-141. The New England Wild Flower Society.
