Lupinus arboreus
coastal bush lupine, tree lupine, yellow bush lupine
ascending or erect, branched, woody.
cauline;
stipules 8–12 mm;
petiole 2–3(–6) cm;
leaflets 5–12, blades 20–60 × 3–10 mm, adaxial surface glabrous.
10–30 cm;
flowers whorled or not.
4–10 cm;
bracts deciduous, 8–10 mm.
4–10 mm.
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.
4–7 cm, hairy.
deciduous, petiolate.
8–12, black to tan, often striped lighter, 4–5 mm.
= 48.
Lupinus arboreus
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
