any of a genus (Coreopsis) of plants of the composite family, having showy heads with yellow, crimson, or maroon ray flowers
See coreopsis in American Heritage Dictionary 4
(kôrˌē-ŏpˈsĭs, kŏr-)
noun
Any of various plants of the genus Coreopsis in the composite family, especially the North American species, having showy radiate flower heads with yellow or, rarely, purplish flowers. Also called tickseed.