
Utah State University/ Steve Dewey
Plant Description
Woolly mullein, also known as Common mullein (Verbascum thapsus) is a biennial taprooted forb. Plants branch only when damaged and can grow to more than 8 ft (2.44 m) tall. First year plants appear as a rosette of leaves 4-12 in (10-31 cm) long, 1-5 in (3-13 cm) wide and covered with woolly hairs. The plant bolts in the second year. Flowering occurs in between July and October, when a dense spike of five-petaled, yellow flowers develops at the top of the shoot. Stem leaves alternate up the stem and decrease in size towards the apex. Native to Eurasia and Africa, woolly mullein was introduced to North America in the mid-1700s as a fish poison.