Narrowflower Lupine

Perennial, 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, Stems or young twigs sparsely to densely hairy, 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 leafl et 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 white, Petals orange or yellow, 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 mo ttled or patchy.

Lupinus angustiflorus is a species of lupine known by the common name narrowflower lupine. It is endemic to California, where it grows in the volcanic soils of the northeastern mountains and Modoc Plateau. It is an erect perennial herb sometimes exceeding one meter in height. Each palmate leaf is made up of 6 to 9 leaflets each up to 6 centimeters long. The inflorescence is up to 34 centimeters long, bearing many flowers each roughly a centimeter long. The flower is cream to pale yellow-orange with a patch of deeper yellow or orange on its banner. The keeled lower petals may be tipped with lavender. The fruit is a hairy legume pod up to 4 centimeters long.