Leaves odd-foliate, 5-9 leaflets making up the leaf, which are ~1-2.5 cm long, ~0.4-0.6 cm wide. Leaves cauline (on stems), alternate, on petioles ~1-3.5 cm long. Petioles have stipules (small, leaf-like appendages fused along base of petiole). Leaflets are oblanceolate (much longer than wide, widening slightly toward the tip). Margins are entire (smooth). Leaves and stems covered with silky hairs, especially on the undersides of leaves, creating a silvery-olive appearance. Erect-branching, sometimes sprawling shrub ~0.5-2 m tall. Inflorescence is a terminal raceme or pinnately arranged cluster of individual flowers on their own pedicels (stalks) spiraling along the rachis or central axis of the cluster. The raceme features bracts (leaf-like structures), which fall off early in flowering. The raceme is ~5-20 cm long at the end of branches, the peduncles bearing them ~2-6 cm long, pedicels bearing the individual flowers ~4-8 mm long. The flower corollas are blue or lavender, 2 lipped, divided into 5 lobes, the lower 2 sometimes fused. The upper lip or banner is ~7-8 mm long, has a yellowish spot in the center, a fringe along the upper edges, and a densely hairy back. The lower lip is ~6-7 mm long. There are 10 stamens. Blooms March through July. Fruit is a stringy or hairy pod ~2.5-3.5 cm long, containing 4-8 seeds, easily visible by the bumps they produce in the pod. The seeds are ~4-5 mm in diameter and a mottled brown. The plant is found on sandy beaches and dunes under 10 m elevation in the coastal strand and dunes of California.
Lupinus chamissonis (Fabaceae): dune bush lupine or beach blue lupine or dune lupine or chamisso bush lupine
The development of this key was partially funded through the Geoscience Diversity Enhancement Program (Award #0703798) and through a course of re-assigned time provided by the CSULB Scholarly and Creative Activities Committee. Thanks also to the students in sections of biogeography, introductory physical geography, GDEP, and LSAMP for "test-driving" various editions of this key.