mullein, any of the 360 species of the genus Verbascum (family Scrophulariaceae), large biennial or perennial herbs native to northern temperate regions, especially eastern Eurasia. The common mullein (V. thapsus) grows 0.6 to 2 metres (2 to 7 feet) tall, has a single, unbranched stem with large, thick, densely velvety leaves, and has pale-yellow, slightly irregular flowers about 2.5 cm (1 inch) across in a crowded terminal spike.
Mulleins are often troublesome weeds in pastures and are common in disturbed areas and along roadsides, but they have also found some uses in the garden. The flowers of the different species vary in colour from white to blue, purple, and red.