Bingen Lupine

Bingen lupine is a perennial lupine to 10 dm tall. It tends to have basal leaves present during flowering, with the lower leaf petioles 3 to 5 times longer than the leaflet blades, while the upper stem leaves may have petioles shorter than the blades. The compound palmate leaves may have from 9 to 11 narrow, oblanceolate leaflets with acute tips. The leaflets may be hairless above and sparsely to very hairy beneath, or they may be equally very haired on both surfaces. Variety subsaccatus tends to have pubescence on both leaflet surfaces.

The flowers are bluish or purple (variety sulphureus has yellow flowers) and found on 6 to 15 cm long racemes (usually less than 10 cm in variety subsaccatus. The calyx is silky and it is asymetrical although it isn't spurred. The upper lip of the flower is bidentate, while the lower is entire. The banner isn't reflexed very much from the wings or keel.