Lupinus arboreus
Lupinus rivularis
coastal bush lupine, tree lupine, yellow bush lupine
river-bank lupine, stream bank lupine
ascending or erect, branched, woody.
decumbent, ascending, or erect, branched, dark brown to red, usually hollow.
cauline;
stipules 8–12 mm;
petiole 2–3(–6) cm;
leaflets 5–12, blades 20–60 × 3–10 mm, adaxial surface glabrous.
cauline;
stipules 7–15 mm;
petiole 3–5 cm;
leaflets 5–9, blades 20–40 × 4–9 mm, adaxial surface glabrous.
10–30 cm;
flowers whorled or not.
open, 15–50 cm;
flowers ± whorled or not.
4–10 cm;
bracts deciduous, 8–10 mm.
3–15 cm;
bracts deciduous, 8–10 mm.
4–10 mm.
5–10 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.
12–16 mm;
calyx bulge or spur 0–1 mm, abaxial lobe entire or ± 3-toothed, 7–9 mm, adaxial lobe 2-toothed, 7–8 mm;
corolla violet, banner glabrous abaxially, lower keel margins glabrous, adaxial margin ciliate claw to tip.
4–7 cm, hairy.
dark, 3–7 cm, sparsely hairy.
deciduous, petiolate.
deciduous, petiolate.
8–12, black to tan, often striped lighter, 4–5 mm.
7 or 8, mottled brown with black line, 3–4 mm.
= 48.
Lupinus arboreus
Lupinus rivularis
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.)
Lupinus rivularis ranges from Mendocino County in California northward through Oregon and Washington. It has been confirmed in British Columbia (where it is of conservation concern) in the extreme southwestern corner of the province, with a single population on southern Vancouver Island and five populations in the lower Fraser Valley.
Lupinus rivularis is distinguished by its absence of wood, banners that are glabrous abaxially, ciliate keels, glabrous leaf surfaces, and violet flowers. It grades into blue-flowered L. arboreus but blooms earlier (late winter, spring) and is not sweet-smelling. L. L. Phillips (1955) considered L. rivularis as synonymous with L. albicaulis.
Lupinus rivularis is widely planted for erosion control in western Oregon; it is of conservation concern in Canada.
(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
