Moth mullein is a biennial weed which produces a basal cluster of leaves during its first year's growth and grows a single stem from 40-150 cm tall during the second season. The basal leaves are dark green, often with a reddish-tinge. These basal leaves are usually shallowly lobed and toothed and oblanceolate in shape. The individual leaves range from 5-15 cm long and 1-3 cm wide. The base of each leaf tapers to a short petiole. The stem leaves are numerous and reduced in size upwards on the stem. The stem leaves become sessile and clasping on the upper stem and are toothed but rarely lobed.
The inflorescence is an open, elongate raceme of bright yellow (sometimes nearly white) flowers. The corolla is 2-3 cm wide and consists of 5 broad, slightly irregular lobes with lower lobes slightly larger..
Moth mullein is a weedy species found in disturbed areas such as fields, roadsides, and waste places.
Moth mullein is an introduced, weedy species from Eurasia which is now common in disturbed areas of North America.
In the Columbia River Gorge it is found between the elevations of 100'-2200' across the length of the Gorge.