Indian paintbrush n 1: erect perennial of eastern and southern United States having showy orange flowers [syn: {butterfly weed}, {orange milkweed}, {chigger flower}, {chiggerflower}, {pleurisy root}, {tuber root}, {Asclepias tuberosa}] 2: any of various plants of the genus Castilleja having dense spikes of hooded flowers with brightly colored bracts [syn: {painted cup}]