any of a genus (Clarkia) of W American wildflowers of the evening-primrose family, having white, rosy, or purple flowers
See clarkia in American Heritage Dictionary 4
(klärˈkē-ə)
noun
Any of various annual, chiefly western North American plants of the genus Clarkia, several of which are cultivated for their showy red, purple, pink, or white flowers.