Lupinus bicolor
Lupinus arboreus
bicolor lupine, field lupine, Lindley's annual lupine, Lindley's lupine, lupine, miniature lupine, Montana lupine, small-flower lupine, two-color lupine, two-colour lupine
coastal bush lupine, tree lupine, yellow bush lupine
ascending or erect, branched or unbranched.
ascending or erect, branched, woody.
cauline;
petiole 1–7 cm;
leaflets 5–8, blades 10–40 × 1–5 mm, adaxial surface glabrous or sparsely pubescent.
cauline;
stipules 8–12 mm;
petiole 2–3(–6) cm;
leaflets 5–12, blades 20–60 × 3–10 mm, adaxial surface glabrous.
4–20 cm;
flowers usually in fewer than 5 whorls, sometimes spirally arranged.
10–30 cm;
flowers whorled or not.
3–10 cm;
bracts deciduous, 4–6 mm.
4–10 cm;
bracts deciduous, 8–10 mm.
1–3.5 mm.
4–10 mm.
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.
14–18 mm;
calyx bulge or spur 0–1 mm, abaxial lobe entire, 5–7 mm, adaxial lobe 2-toothed, 5–9 mm;
corolla usually yellow, rarely lilac to purple, banner patch darker or not or white, banner glabrous abaxially, lower keel margins glabrous, adaxial margin ciliate from claw to tip.
1–3 × 0.3–0.6 cm, pubescent.
4–7 cm, hairy.
deciduous, petiolate.
deciduous, petiolate.
5–8.
8–12, black to tan, often striped lighter, 4–5 mm.
= 48.
= 48.
Lupinus bicolor
Lupinus arboreus
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.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Lupinus arboreus is known from the central California coast southward to northern Baja California; it was introduced as a sand binder and has become naturalized in northern California, Oregon, Washington, and southern British Columbia.
Lupinus arboreus grades into L. rivularis in the North Coast of California. Plants with yellow petals and sweet-smelling flowers are widely cultivated as a sand binder. Hairier plants from the western San Francisco Bay area with yellow banners and blue wings have been called var. eximius; plants with glabrous leaflets and purple petals have been called L. propinquus. Lupinus arboreus hybridizes with L. littoralis and probably other species. Seeds of L. arboreus species are toxic.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
- Local floras:
BC, 
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
PNW Herbaria, Turner Photog. 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
- Local floras: BC, CA, OR, WA
- Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria, Turner Photog.
- WildflowerSearch
- iNaturalist (observations)
- USDA Plants Database
- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
