Naturalising the Exotic and Exoticising the Naturalised: Horticulture, Natural History and the Rosy Periwinkle

Abstract

Abstract The rosy periwinkle, a plant originating in the rainforest of Madagascar, is best known for its use in modern biomedicine as a cancer therapy and as a symbol of the importance of biodiversity conservation. Yet images of the plant as a novel therapeutic and an endangered exotic obscure its commonness, for it is both naturalised in many parts of the world as a weed and has long been used as an ornamental plant in greenhouses and gardens. This seeming contradiction is the result of the rosy periwinkle's long history as a horticultural variety, especially its transition over a two-hundred-year period from being understood as a hothouse exotic to being seen as native and commonplace. Horticultural practices generated changes in the distribution and biology of the rosy periwinkle and this in turn generated changes in people's valuation of the species. Through a horticultural history of the rosy periwinkle, this paper explores how ideas about what constitutes an exotic or naturalised species, and the value attached to these, can dramatically shape and then reshape the natural history of a species. It suggests why such attention to such plasticity is important both for historians and for conservation.