Palestine lupine

The species are mostly herbaceous perennial plants 0.3–1.5 m (0.98–4.9 ft) tall, but some are annual plants and a few are shrubs up to 3 m (9.8 ft) tall with one species (Lupinus jaimehintoniana from the Mexican state of Oaxaca) up to 8 m (26 ft) high with a trunk 20 cm (7.9 in) in diameter. They have a characteristic and easily recognized leaf shape, with soft green to grey-green leaves which in many species bear silvery hairs, often densely so. The leaf blades are usually palmately divided into 5–28 leaflets or reduced to a single leaflet in a few species of the southeastern United States. The flowers are produced in dense or open whorls on an erect spike, each flower 1–2 cm long, with a typical peaflower shape with an upper 'standard' or 'banner', two lateral 'wings' and two lower petals fused as a 'keel'. Due to the flower shape, several species are known as bluebonnets or quaker bonnets. The fruit is a pod containing several seeds.