Verbascum dumulosum (shrubby mullein)

Verbascum dumulosum grows among the ruins of the ancient city of Termessus in Antalya, southern Turkey.

William Turrill, former Keeper of the Herbarium, writes in Curtis’s Botanical Magazine: ‘Termessus was an ancient city that resisted and was by-passed by Alexander the Great…What may be the history of our plant, known only as growing on ancient ruins, an artificial habitat, is at present a matter for speculation.’

Verbascum dumulosum flowers (Image: Wolfgang Stuppy)

Verbascum dumulosum is a subshrub growing up to 30 cm tall and over 60 cm across. The branched stems have a dense covering of soft, short, greyish-white or yellowish hairs, which also occur on both surfaces of the lanceolate (narrowly ovate and tapering to a point at the apex) to elliptic (broadest at the middle with two equal rounded ends) leaves. The leaves are in lax (loose) rosettes at the ends of the short branches.

The round, bright yellow flowers are 1–2 cm wide and up to 35 are held in each raceme (a type of flower cluster that is unbranched and bears flowers along a central axis).

Verbascum dumulosum is cultivated as an ornamental.

Verbascum dumulosum growing in the Alpine House at Kew (Image: Richard Wilford)

This is a hardy species, at least in British gardens, but it cannot tolerate dampness in winter. Cultivation is usually most successful under glass and it is easily grown in a well-ventilated alpine house or a cold frame that is covered during wet weather, to protect the downy leaves from the rain.

On a rock garden it is best planted in a sunny crevice to provide the necessary drainage and the rosettes should be angled away from the horizontal to prevent rainwater accumulating on the leaves. New shoots will sprout from the woody stems, so any rotten rosettes can be cut away in late winter.

Propagation can be by seed, although hybrids can easily occur if other species are grown nearby. Otherwise side shoots can be detached with a short portion of stem (i.e. taken with a ‘heel’) after flowering, to use as cuttings. They often root in just a few weeks.

Verbascum dumulosum can be seen in the Davies Alpine House at Kew.

Spirit-preserved specimens of Verbascum dumulosum are held in Kew’s Herbarium, where they are made available to researchers, by appointment. The details of one of these specimens can be seen on-line in the Herbarium Catalogue.

Search Kew’s science databases for more information on this species

Visit Kew’s Davies Alpine House

Read the Alpine & Rock Garden Team blog

Buy 'Alpines from Mountain to Garden' by Richard Wilford

Curtis’s Botanical Magazine (Wiley-Blackwell)

Royal Horticultural Society - Verbascum dumulosum