Lupinus arboreus Sims
Yellow bush lupine, bush lupine
Yellow bush lupines are native to western North America. Like other members of the extensive pea family, these lupines and their symbiotic bacteria trap atmospheric nitrogen, converting it to a form that provides the plant with necessary nutrients. Hence lupines can grow in areas, like sand dunes, that are too deficient in nitrogen to support other plants. A bright yellow dye can be extracted from the flowers. Outside of their native habitat, yellow bush lupines are now considered to be invasives.
Identification: These lupines can reach 5-6½' (1.5-2 m) in height, and about 4' (1.2 m) around, significantly larger than other lupine species. They produce deep roots which help to stabilize coastal sandy areas. Leaves are silky, dark green or gray-green, palm-like in appearance, with 5-12 leaflets on each leaf. Each leaflet is ¾-2" (2-6 cm) long. Flowers occur in spikes 6" (15 cm) long. They have a sweet scent. Usually yellow, they may be lilac or blue instead.
Lupinus arboreus at the Lady Bird Johnson Wildflower Center
Lupinus arboreus on Plants for a Future, a resource and information centre for edible and otherwise useful plants
Lupinus arboreus at the Oregon Flora Image Project
Lupinus arboreus at the U.S. Department of Agriculture Forest Service
Lupinus arboreus on Wikipedia
Lupinus arboreus on CalPhotos
Lupinus arboreus description by Thomas H. Kent, last updated 25 May 2020.