Lupinus villosus, commonly known as lady lupine, pink sandhill lupine, or hairy lupine, is a species of flowering plant in the family Fabaceae. It is endemic to the southeastern United States, where it occurs in sandy, fire-maintained habitats.
Lupinus villosus is an annual or biennial herb, sometimes behaving as a short-lived perennial, forming erect to somewhat sprawling clumps from a woody crown.
Stems are multiple from the base and densely covered with long, silvery-white, villous hairs. Leaves are unifoliolate, alternate, and clustered toward the base of the plant, elliptic to oblong, typically 6âÂÂ15 cm long, and similarly covered in long, silky hairs.
Inflorescences are terminal racemes 10âÂÂ30 cm long, bearing numerous pink to lavender flowers. Individual flowers are approximately 1âÂÂ1.5 cm long and display a prominent maroon patch on the banner petal. Fruits are elongated, flattened legumes densely covered with silvery hairs.
Plants typically reach 20âÂÂ60 cm (8âÂÂ24 inches) in height.
The species was described by Carl Ludwig Willdenow in 1802.
Synonyms include Lupinus integrifolius Desr. and Lupinus pilosus Walter, both later homonyms and therefore illegitimate names.
Lupinus villosus belongs to a group of unifoliolate lupines endemic to the southeastern United States, which have been the subject of recent systematic revision.
Within the unifoliolate southeastern Lupinus species complex, Lupinus villosus can be distinguished by:
It differs from Lupinus westianus and Lupinus aridorum in its more sprawling growth form and longer, shaggy hairs.
Lupinus villosus is endemic to the southeastern United States, occurring from North Carolina south through Florida and west to Louisiana, including Alabama, Georgia, Mississippi, and South Carolina.
It inhabits longleaf pine sandhills, sandy roadsides, and other well-drained sandy habitats. The species is strongly associated with open environments maintained by periodic fire.
Flowering occurs from March to May, with additional flowering sometimes observed from June to August.
Lupinus villosus is ranked as G4 (apparently secure) globally by NatureServe, indicating that it is widespread and relatively stable overall.
Despite its overall security, the species is locally rare at the edges of its range, particularly in North Carolina and Louisiana. Threats include habitat loss from development, fire suppression, and roadside maintenance practices, which can either benefit or harm populations depending on management intensity.
The species depends on disturbance, especially fire, to maintain suitable open habitat conditions, and declines may occur in areas where natural fire regimes are disrupted.