erect perennial strong-scented with serrate pointed leaves and a loose panicle of yellowish flowers; the eastern United States
同义词：horse balm, horseweed, stoneroot, stone-root, richweed, stone root, Collinsonia canadensis
common North American weed with linear leaves and small discoid heads of yellowish flowers; widely naturalized throughout temperate regions; sometimes placed in genus Erigeron
同义词：horseweed, Canadian fleabane, fleabane, Conyza canadensis, Erigeron canadensis
