Lupinus arbustus
Lupinus rivularis
grassland lupine (ssp. neolaxiflorus), long-spur lupine, Montana lupine (ssp. pseudoparviflorus), spur lupine
river-bank lupine, stream bank lupine
erect, ascending, or decumbent, branched.
decumbent, ascending, or erect, branched, dark brown to red, usually hollow.
cauline and basal;
stipules 4–9 mm;
petiole 2–16 cm;
leaflets 7–10(–13), blades 20–70 × 3–15 mm, adaxial surface strigose.
cauline;
stipules 7–15 mm;
petiole 3–5 cm;
leaflets 5–9, blades 20–40 × 4–9 mm, adaxial surface glabrous.
open, 3–18 cm;
flowers whorled.
open, 15–50 cm;
flowers ± whorled or not.
2–5 cm;
bracts deciduous, 3–6 mm.
3–15 cm;
bracts deciduous, 8–10 mm.
1–7 mm.
5–10 mm.
8–14 mm;
calyx spur distinct, 1–3 mm, abaxial lobe 3-toothed, 2.5–5 mm, 1–3 mm, adaxial lobe 2-toothed, 2–4 mm;
corolla blue, purple, pink, white, or yellowish, banner patch white, yellowish, or absent, banner hairy abaxially, wings with dense hair patch outside near tip, lower keel margins glabrous, adaxial margin ciliate.
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.
2–3 cm, silky.
dark, 3–7 cm, sparsely hairy.
deciduous, petiolate.
deciduous, petiolate.
3–6, tan, 5–6 mm.
7 or 8, mottled brown with black line, 3–4 mm.
Lupinus arbustus
Lupinus rivularis
Lupinus arbustus is known from the Cascade and Klamath ranges, San Gabriel Mountains, Sierra Nevada, and the Great Basin area in California; Owyhee Desert in Idaho and Oregon; eastern Washington and western Montana; and western Juab and Tooele counties, Utah.
Lupinus arbustus is separated from the argenteus group by the presence of hairs on the corolla wings. Recognition of subspecies and varieties of this already complex species leads to precarious separation among taxa.
Lupinus variegatus A. Heller (1912, not Poiret 1814) is an illegitimate name that pertains here.
(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
