any of a genus (Verbascum) of tall plants of the figwort family, with spikes of yellow, lavender, or white flowers
See mullein in American Heritage Dictionary 4
(mŭlˈən)
noun
Any of various Eurasian plants of the genus Verbascum, especially V. thapsus, a tall plant having closely clustered yellow flowers and leaves covered with dense woolly down. Also called flannel leaf, velvet plant.