Verbascum dumulosum (shrubby mullein)
Verbascum dumulosum at Kew Gardens
Verbascum dumulosum P.H.Davis & Hub.-Mor.
shrubby mullein, dwarf mullein
Not evaluated according to IUCN Red List criteria.
Grows among ruins, at an altitude of around 950 m.
About this species
The genus Verbascum is represented by around 228 species in Turkey. Verbascum dumulosum is one of about 176 species found only in Turkey.
Verbascum dumulosum was introduced to cultivation from a collection of seeds made by Peter Davis (professor of plant taxonomy at Edinburgh University) and was widely grown by alpine gardeners in the 1950s and 1960s. In April 1952, the same year this species was described by Davis, it was awarded a Preliminary Commendation by the RHS and an Award of Merit a year later. It began to slip out of cultivation until seed collectors Jim and Jenny Archibald collected and reintroduced seed in the 1980s, and in May 1999 it was awarded a First Class Certificate.
Verbascum dumulosum is closely related to another Turkish endemic, V. pestalozzae, which also comes from Antalya but grows on limestone rocks at around 2,000 m. That is a more dwarf species, with shorter, fewer-flowered racemes (a type of flower cluster that is unbranched and bears flowers along a central axis) and slightly larger, yellow flowers.
Geography and distribution
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.’
Overview: Verbascum dumulosum is a subshrub growing up to 30 cm tall and over 60 cm across.
Stems: 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.
Leaves: The leaves are in lax (loose) rosettes at the ends of the short branches.
Flowers: 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.
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.
This species at Kew
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 online in the Herbarium Catalogue.
Beentje, H. (2010). The Kew Plant Glossary. Royal Botanic Gardens, Kew.
Rolfe, R. (2000). Plant Awards 1998-1999. Quart. Bull. Alpine Gard. Soc. Gr. Brit. 68: 202-203
Turrill, W. (1955). Verbascum dumulosum. Curtis's Bot. Mag. 170 (4): t. 258
Wilford, R. (2010). Alpines from Mountain to Garden. Royal Botanic Gardens, Kew.
Kew Science Editors: Malin Rivers and Richard Wilford
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