Tall Silky Lupine

Perennial, Herbs, Stems woody below, or from woody crown or caudex, Taproot present, Nodules present, Stems erect or ascending, Stems less than 1 m tall, Stems solid, Stems or young twigs sparsely to densely hairy, Stems silvery, canescent, tomentose, cobwebby, or wooly, Leaves alternate, Leaves petiolate, Stipules conspicuous, Stipules setiform, subulate or acicular, Stipules persistent, Stipules adnate to petiole, Leaves compound, Leaves palmately 5-11 foliate, Leaf or leaflet margins entire, Leaflets 5-9, Leaves hairy on one or both surfaces, Inflorescences racemes, Inflorescence terminal, Bracts conspicuously present, Bracts very small, absent or caducous, Bracteoles present, Flowers zygomorphic, Calyx 5-lobed, Calyx 2-lipped or 2-lobed, Calyx hairy, Petals separate, Corolla papilionaceous, Petals clawed, Petals orange or yellow, Petals blue, lavander to purple, or violet, Petals bicolored or with red, purple or yellow streaks or spots, Banner petal ovoid or obovate, Wing petals narrow, oblanceolate to oblong, Wing tips obtuse or rounded, Keel petals auriculate, spurred, or gibbous, Stamens 9-10, Stamens or anthers dimorphic, alternating large and small, Stamens monadelphous, united below, Filaments glabrous, Style terete, Fruit a legume, Fruit unilocular, Fruit freely dehiscent, Fruit elongate, straight, Fruit oblong or ellipsoidal, Fruit exserted from calyx, Fruit internally septate between the seeds, Fruit hairy, Fruit 3-10 seeded, Seeds ovoid to rounded in outline, Seed surface smooth, Seeds olive, brown, or black, Seed surface mottled or patchy.

Lupinus elatus is a species of lupine known by the common name tall silky lupine. It is endemic to California, where it is known from the Transverse Ranges above Los Angeles, and possibly also from the southernmost slopes of the Sierra Nevada. Its habitat includes dry areas in the forests of the mountains. This is an erect perennial herb reaching a maximum height near 90 centimeters. Each palmate leaf is made up of 6 to 8 leaflets up to 8 centimeters long. The herbage is coated in silvery silky to woolly hairs. The inflorescence is a long raceme of flowers, each about a centimeter long and arranged in whorls. The flower is purple or blue with a pale yellow patch on its banner. It yields a legume pod 2 or 3 centimeters long. This is a host plant to the Southern California native butterfly subspecies known as the San Gabriel Mountains Arrowhead Blue (Glaucopsyche piasus ssp. gabrielina).