Herbs, annual, 0.5–4 dm, pubescent. Cotyledons decid­uous, petiolate. Stems ascending or erect, branched or unbranched. Leaves cauline; petiole 1–7 cm; leaflets 5–8, blades 10–40 × 1–5 mm, adaxial surface glabrous or sparsely pubescent. Peduncles 3–10 cm; bracts deciduous, 4–6 mm. Racemes 4–20 cm; flowers usually in fewer than 5 whorls, sometimes spirally arranged. Pedicels 1–3.5 mm. Flowers 4–10 mm; calyx abaxial lobe entire, 4–6 mm, adaxial lobe deeply cleft, 2–4 mm; corolla usually blue, rarely light blue, pink, or white, banner spot white, becoming magenta, upper keel mar­gins usually ciliate near apex, rarely glabrous, sometimes blunt, banner longer than wide. Legumes 1–3 × 0.3–0.6 cm, pubescent. Seeds 5–8. 2n = 48.

Phenology: Flowering late winter–spring (Mar–Jun).
Habitat: Open or disturbed areas.
Elevation: 0–1600 m.

Distribution

• Generated Map
• Legacy Map

B.C., Ariz., Calif., Oreg., Wash., Mexico (Baja California, Baja California Sur, Sonora).

Discussion

Lupinus bicolor is naturalized in Arizona. The named subspecies and varieties do not conform to consistently recognizable geographical or morphological entities (D. B. Dunn 1955). Vigorous plants with larger flowers may be confused with L. nanus. In California, plants on the Outer North Coast Ranges may persist for two growing seasons. Lupinus bicolor (as L. polycarpus) has been reported from Alabama (A. R. Diamond 2016) and Michigan (E. G. Voss and A. A. Reznicek 2012).

Lupinus micranthus Douglas (1829, not Gussone 1828) is an illegitimate name that pertains here.

Selected References

None.

Lower Taxa

None.