Lupinus truncatus Hook. & Arn.

Annual, Herbs, Taproot present, Nodules present, Stems erect or ascending, Stems less than 1 m tall, Stems solid, Stems or young twigs glabrous or sparsely glabrate, 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 reddish brown, maroon, 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 h airy, Fruit 3-10 seeded, Seeds ovoid to rounded in outline, Seed surface smooth, Seeds olive, brown, or black, Seed surface mottled or patchy.

Lupinus truncatus is a species of lupine known by the common name collared annual lupine.

It is native to the coastal mountain ranges and canyons of Baja California and California as far north as the San Francisco Bay Area. It grows in slope habitat such as chaparral and woodland, including areas that have recently burned.