Dark Mullein is a tall plant with a spear of rich yellow flowers containing purple haired stamens. It has hairy leaves whereas the more Common Great Mullein has more woolly leaves.

Several other species of Mullein with similar leaves and flowers have been recorded in VC55 or may turn up

This is a difficult genus, compounded by a large number of hybrids, and garden escapes that may become established briefly in the wild.

The leaves are dark green above, hairy beneath; all the stamens are reniform (kidney-shaped) with violet hairs.  There are 2 or more flowers per bract, each with 2 small bracteoles. The basal leaves are cordate at the base. 

A photograph of the whole plant, including basal leaves, and details of flowers.

Found on road verges and embankments, in hedge banks and other grassy places, on walls and in cultivated ground, including arable field margins. It prefers well-drained calcareous soils.

In flower during June, July, August and September.

Usually biennial - in the first year the leaves form a rosette. In the second year the stem extends from the rosette and leaves are alternate along it.

Fairly widespread in Britain in areas with calcareous soil, but can be rather local elsewhere.

Infrequent and local in Leicestershire and Rutland, and may be introduced or escaped from cultivation. In the The Flora of Leicestershire (Primavesi & Evans 1988) it was found in 6 of the 617 tetrads.

In the current checklist (Jeeves 2011) it is listed as Native; limestone quarries on the Oolite and disturbed ground elsewhere; scarce.

It was on the 2011 VC55 Rare Plant Register (Jeeves, 2011) but is not on the current RPR (Hall & Woodward, 2022); it is listed as 'data deficient' because it is not clear whether records are of introduced/escaped plants or natives.