In search of Cape Ericas: - research visit to South Africa, October 2022

Abstract

Visitors to the Arboretum’s heather garden will already be familiar with hardy heathers : the winter-flowering heather, Erica carnea, is particularly striking, producing carpets of flowers as early as February. At the other end of the season comes the Cornish heath, E. vagans. In between, amidst the distraction of activity in the Rosarium, our native species are in action: the cross-leaved heath, Erica tetralix, and bell heather, E. cinerea, as well as their close relative Calluna vulgaris – the common heather. In total, there are around 20 species of the genus Erica native to the heathlands of Europe and the Mediterranean. Although they span a wide flowering season, they are generally rather similar in form: low growing shrubs with mostly small, pinkish flowers. The exceptions stand out, such as the tree-like forms of the tree heather, E. arborea, with its white flowers, and besom heath, E. scoparia, with its smaller, inconspicuous wind-pollinated flowers. Imagine then, a heathland landscape with hundreds of different species of heather with flowers in shades of green, white, yellow, orange, pink through to red and from less than 1 mm up to 5 cm long, flowering all year round. Welcome to the Cape Floristic Region (CFR), a botanically unique area around the size of Eastern Norway in the south-western corner of South Africa. Of the approximately 850 species of Erica, 700 of them are only found in the CFR. The long-standing question in Cape Erica is ‘why so many species?’, whilst the increasingly urgent concern is now for their future: many are threatened with extinction by habitat destruction and transformation, invasive species, and climate change. What can be done about this? Join us for a snapshot of heather diversity on show in October of 2022 and hear about some of the things we are doing to tackle both questions.