The plants first form a dense rosette of leaves at ground level, subsequently sending up a tall flowering stem. Biennial plants form the rosette the first year and the stem the following season. The leaves are spirally arranged, often densely hairy, though glabrous (hairless) in some species. The flowers have five symmetrical petals; petal colours in different species include yellow (most common), orange, red-brown, purple, blue, or white. The fruit is a capsule containing numerous minute seeds.
Mullein most frequently grows as a colonist of bare and disturbed soil, usually on sandy or chalky ones. It grows best in dry, sandy or gravelly soils, although it can grow in a variety of habitats, including banksides, meadows, roadsides, forest clearings and pastures.
Mullein is used medicinally for the lungs and throat. It is a mild sedative to the lungs and can help when infections first present themselves. Chopped leaves are especially useful for asthmatics when smoked. The flower of Mullein can also be used as an earache remedy.