Bluebonnet is a name given to any of a number of purple-flowered or blue-flowered species of the genus Lupinus and is collectively the state flower of Texas. The shape of the petals on the flower resembles the bonnet worn by pioneer women to shield them from the sun. Species often called bluebonnets include:Lupinus argenteus, silvery lupine Lupinus concinnus, Bajada lupine Lupinus havardii, Big Bend bluebonnet or Chisos bluebonnet Lupinus perennis, wild lupine or blue lupine Lupinus plattensis, Nebraska lupine Lupinus subcarnosus, sandyland bluebonnet or buffalo clover Lupinus texensis, Texas bluebonnet or Texas lupine