Lupinus texensis, the Texas bluebonnet or Texas lupine is a species of lupine endemic to Texas, plus the Mexican states of Coahuila, Nuevo León, and Tamaulipas. It is an annual which begins its life as a small, gravel-like seed. The seed has a hard seed coat that must be penetrated by wind, rain, and weather over the course of a few months (but sometimes several years). In the fall, the bluebonnets emerge as small seedlings with two cotyledons, and later a rosette of leaves that are palmately compound, with five to seven leaflets 3–10 cm long, green with a faint white edge and hair.
Texas recognizes all native lupine species occurring in the state as the official state flower.