Verbascum thapsus, the great mullein, greater mullein or common mullein is a species of mullein native to Europe, northern Africa, and Asia, and introduced in the Americas and Australia. It is a hairy biennial plant that can grow to 2 m tall or more. Its small, yellow flowers are densely grouped on a tall stem, which grows from a large rosette of leaves. It grows in a wide variety of habitats, but prefers well-lit, disturbed soils, where it can appear soon after the ground receives light, from long-lived seeds that persist in the soil seed bank. It is a common weedy plant that spreads by prolifically producing seeds, and has become invasive in temperate world regions. It is a minor problem for most agricultural crops, since it is not a competitive species, being intolerant of shade from other plants and unable to survive tilling. It also hosts many insects, some of which can be harmful to other plants. Although individuals are easy to remove by hand, populations are difficult to eliminate permanently. Although commonly used in traditional medicine, no approved drugs are made from this plant. It has been used to make dyes and torches. Description V. thapsus is a dicotyledonous plant that produces a rosette of leaves in its first year of growth. The leaves are large, up to 50 cm long. The second-year plants normally produce a single unbranched stem, usually 1–2 m tall. In the eastern part of its range in China, it is, however, only reported to grow up to 1.5 m tall. The tall, pole-like stems end in a dense spike of flowers that can occupy up to half the stem length. All parts of the plants are covered with star-shaped trichomes. This cover is particularly thick on the leaves, giving them a silvery appearance. The species' chromosome number is 2n = 36. On flowering plants, the leaves are alternately arranged up the stem. They are thick and decurrent, with much variation in leaf shape between the upper and lower leaves on the stem, ranging from oblong to oblanceolate, and reaching sizes up to 50 cm long and 14 cm across (19 inches long and 5 inches wide). They become smaller higher up the stem, and less strongly decurrent down the stem. The flowering stem is solid and 2–2.5 cm (nearly an inch) across, and occasionally branched just below the inflorescence, usually following damage. After