About fifty feet from the wooly mullein (Verbascum thapsus) growing the McArthur Swamp (Shasta County CA) featured in my last post were several moth mullein (Verbascum blattaria) plants. These two plants look so different it is sometimes difficult to remember that they are closely related, belonging to the same genus, Verbascum.
Although the wooly mullein and moth mullein do not resemble each other at first glance, they have many similarities. Both plants are aliens introduced from Eurasia and are now widespread throughout temperate North America. They can be found in disturbed places and waste areas. When moth mullein invades agricultural crops and pastures, it too can become a problem and is thus often classified as a noxious weed. Both the wooly and moth mulleins are biennials growing as a rosette of basal leaves the first year. In the second year a single flowering stem arises from the plants’ tap roots. The flowering stem leaves of both species are alternate and become smaller going up the stem, with the leaves becoming more sessile (no stalk) and clasping the stem near the tip. The fruit of both plants is a capsule containing many tiny seeds.
Unlike the wooly mullein, the moth mullein is not covered in dense, soft, whitish hairs. The moth mullein basal leaves are a dark green with a slight reddish tinge while the leaves on the flowering stalk are a brighter green. The basal and stem leaves are shallow lobed or toothed. Both wooly and moth mullein have five lobed bright yellow (occasionally whitish) flowers, however the moth mullein’s flower is large, flat and has a maroon colored center. Many moth mullein flowers occur at the end of each flowering stalk but are not crowded together like those of the wooly mullein.
Each mullein is interesting and beautiful in its own way.