Geography and distribution
Berkheya purpurea is found in South Africa at elevations of 1,500–3,000 m from the mountains of the Eastern Cape to the Drakensberg in KwaZulu-Natal and also in Lesotho and Orange Free State.
Overview: Berkheya purpurea is a rhizomatous perennial forming a dense prickly rosette of foliage.
Leaves: The leaves measure 25–45 cm long and 4–10 cm wide and are green on the upper side, downy on the underside with spiny margins.
Flowers: The single flowering stem, up to 1 m high, appears from December to April in the wild and June to August in cultivation. The flower heads (capitula) are carried on short side branches on the upper part of the flowering stalk, and the buds open in succession from the top of the stem downwards. Several capitula may open simultaneously. Each capitulum has a ring of pale mauve outer ray florets with central dark purple disc florets, although occasionally the ray florets may be white. A circle of spiny green bracts (phyllaries) protects the capitula.
Fruits: The pappus (scales surrounding the apex of the fruit) is light green at first and then turns light to dark brown as the fruits (achenes) mature.
The flowers are pollinated by bees.
Purple berkheya is cultivated as an ornamental.
Berkheya purpurea was apparently grown at Kew around 1917 but has only recently become popular in gardens in Britain; it is now available from commercial seed companies.
In Britain, plants raised from seed (ideally sown after collecting in the autumn or delayed until the following spring) are planted out in the garden in spring. They grow best in well-drained soil and full sun. They look good in groups and planted among low grasses, as seen in the wild.
Berkheya purpurea is also propagated by division of the rootstock.
Burkheya purpurea illustrated by Rachel Pedder-Smith © (2006)
This species at Kew
Purple berkheya can be seen growing in the Rock Garden at Kew, and in the South African Bed of the Southern Hemisphere Garden at Wakehurst.
Pressed and dried, and alcohol-preserved specimens of Berkheya purpurea are held in Kew’s Herbarium, where they are available to researchers from around the world, by appointment. The details of some of these specimens, including images, can be seen online in the Herbarium Catalogue.
View details and images of specimens
Illustration from Curtis's Botanical Magazine
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