[The Lupines of the Columbia River Gorge of Oregon and Washington]

Bicolored Lupine, Miniature Lupine, Two-color Lupine

Lupinus bicolor ssp. bicolor

Synonyms: Lupinus bicolor ssp. bicolor, Lupinus bicolor var. bicolor, Lupinus bicolor ssp. microphyllus, Lupinus bicolor var. microphyllus, Lupinus bicolor ssp. tridentatus, Lupinus bicolor var. tridentatus, Lupinus nanus var. apricus, Lupinus vallicola ssp. apricus

The photograph at left shows a close-up of the banner of bicolored lupine as seen on seen on the benches above Doug's Beach in the Columbia River Gorge on March 24, 2008. The photo at right shows a close-up view of the inflorescence of bicolored lupine as seen atop the ridge at Mill Creek Ridge Preserve, a Columbia Land Trust property near The Dalles, OR......April 11, 2024.

Bicolored Lupine, Miniature Lupine, Two-color Lupine: Lupinus bicolor ssp. bicolor (Synonyms: Lupinus bicolor ssp. bicolor, Lupinus bicolor var. bicolor, Lupinus bicolor ssp. microphyllus, Lupinus bicolor var. microphyllus, Lupinus bicolor ssp. tridentatus, Lupinus bicolor var. tridentatus, Lupinus nanus var. apricus, Lupinus vallicola ssp. apricus)

The photo at right shows bicolored lupine as found at Major Creek..........May 13, 2000. Although at first this species seems similar to miniature lupine (L. micranthus), its banner is reflexed further backwards and has a large central, white blotch on the banner.

Characteristics:

Small-flowered lupine is a small annual ranging from 10-40 cm in height with simple to freely branched stems. Its herbage is sparsely to densely covered with many short hairs and less numerous, longer brownish hairs. The leaves are compound palmate with 5-8 linear-oblanceolate leaflets with the individual leaflets 1.5-3 cm long. The upper leaf surfaces are hairless while the lower surfaces have appressed hairs . The leaf petioles are longer than the individual leaflets.

The inflorescence is a very short raceme of several flowers which is raised above the leaves. Individual flowers range from 7-9 mm long and are found on short pedicels from 1-2 mm long. The calyx lobes are unequal in length but are roughly 3 mm long. The upper calyx lobe is double-toothed. The petals are blue and the banner is often white-centered. Violet spots may or may not be found in the white banner. The banner is noticeably reflexed from the wings, and is roughly equal to the keel in length. The brownish pods range from 1.5-2 cm long and 3-5 mm wide and are covered with appressed hairs. 4-8 seeds may be found within the pods.

Bicolored lupine may be easily confused with miniature lupine Lupinus micranthus, but the former species has flowers with the banner reflexed further backwards so the space between the banner and wings is more open. The flowers of the latter species tend to be slightly shorter, ranging from 5-7 mm in length with the banner less reflexed.

Habitat:

Bicolored lupine is found growing in open prairies or gravelly areas at low elevations.

Range:

Small-flowered lupine is found west of the Cascade Mts. from British Columbia south to California.

It may be found in the Columbia River Gorge between the elevations of 100' to 700' between the Wind River and Dallesport, WA.

The photos above shows a close-up side view (photo at left) and dorsal view down to the upper, back side of the banner (photo at right). Note the lack of hairs on the back of the banner and the long hairs that cover the calyx. Photographed along the Horsethief Butte Trail..........May 24, 2006.

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The photos above show bicolored lupine as seen on the grassy benches above Doug's Beach in the central Columbia River Gorge..........March 24, 2008.

Bicolored lupine as seen in meadow areas on the grounds of The Dalles Discovery Center.........April 5, 2016.

Palmately compound leaf of Bicolored Lupine, Miniature Lupine, Two-color Lupine: Lupinus bicolor ssp. bicolor (Synonyms: Lupinus bicolor ssp. bicolor, Lupinus bicolor var. bicolor, Lupinus bicolor ssp. microphyllus, Lupinus bicolor var. microphyllus, Lupinus bicolor ssp. tridentatus, Lupinus bicolor var. tridentatus, Lupinus nanus var. apricus, Lupinus vallicola ssp. apricus) -

The dorsal surface of the compound palmate leaf (left) and seed pods (right) of bicolored lupine from Major Creek.........May 13, 2000.

Bicolored lupine blooming low on the southeastern slopes of Sevenmile Hill several miles northwest of The Dalles, Oregon.........March 30, 2015.

Bicolored lupine as seen at left along the Old Highway at Major Creek in the Columbia River Gorge..........May 10, 2009. The photo at right shows a close-up of the inflorescence of bicolored lupine as seen on USFS lands just east of Major Creek, Columbia River Gorge.......April 3, 2018..

Bicolored lupine blooming under the powerlines at Catherine Creek, Columbia River Gorge...........April 8, 2014.

Paul Slichter