Slender-petaled Thelypodium

Thelypodium stenopetalum is a rare species of flowering plant in the mustard family known by the common names slenderpetal thelypody, slender-petaled thelypodium and slender-petaled mustard. It is endemic to the San Bernardino Mountains of southern California, where it is known from only three or four extant occurrences in moist mountain meadows near Big Bear Lake. Its remaining habitat is considered seriously threatened and the plant is a federally listed endangered species in the United States.