Streptanthus cutleri

Streptanthus cutleri, known as Cutler's jewelflower, is a species of annual flower only found in the Big Bend region of Texas. Its specific epithet and common name both reference Hugh Carson Cutler, who first collected the plant in 1937. A second specimen was later collected when the plant was in fruit, and this holotype was collected at the exact location as the first specimen, in Maravillas Canyon near Black Gap. Its distinguishing characteristic is that only two petals of each its flowers is enlarged....read more on Wikipedia.