Photo: Roger Butterfield
Most species in the Verbascum genus have gray, woolly leaves born in a rosette at the base of the plant and erect bloom stalks covered in very small flowers. There are about 360 species, and the majority are biennials. The common name is mullein, and it likes full sun and well-drained, but not rich soil. Plants have deep tap roots and do not like to be disturbed once they are established, and they readily self sow. (Deadhead to avoid self sowing!)
In my Midwest garden, I have V. chaixii (/shake see eye) that is native to southern Europe and often called the nettle-leaved mullein. It is a 3-foot tall perennial with a basal rosette of felted leaves that gets about a foot wide and a tall phallus-like stalk with tiny yellow flowers. It grows in zones 4 through 8 and has an imposing architectural presence growing either singly or in groups.
Another imposing specimen is black mullein with flowers that have dark purple centers, but it seems slightly less hardy. Supposedly, witches in the middle ages used this variety in their brews.