The Sida cuneifolia-Complex (Malvaceae) in Africa

Abstract

Summary. The Sida cuneifolia-complex-usually considered to consist of a single widespread species only-is shown to consist of six distinct species: S. cuneifolia Roxb. endemic to India and five species in Africa. Four of the African species are without validly published names and are described here: S. massaica, S. tanaensis, S. shinyangensis and S. tenuicarpa. Sida schimperiana A. Rich. (1847) was described from a Schimper-collection from Ethiopia. For the next 100 years this name was used for all African material belonging to this complex. Clement (1957)-while working on N American Sida commented upon the similarity between S. schimperiana and S. cuneifolia Roxb., an Indian species described in 1832. Clement considered the two to be the same species, a view which has since then been generally accepted by botanists working on African floras-Cufodontis (1959), Hauman (1963), Agnew (1974). My interest in this group stems from my work with Malvaceae for the Flora of Ethiopia. It soon became clear that the Ethiopian material of 'S. cuneifolia' could be divided into two quite distinct taxa with no intermediate collections whatsoever. Examination of East African material showed that both Ethiopian taxa were widespread in Kenya and northern Tanzania, but also revealed here three further taxa all considerably more restricted in their distribution. All these five taxa are separable by differences in structure and sculpturing of the mericarps as well as by differences in indumentum and flower-size, and I see no reason not to consider them as distinct species. Comparison of these species with the true S. cuneifolia from India shows this to be another quite distinct species which is not identical with any of those from Africa. (Fig. 1.) The group is well-defined within Sida. The species are small shrubs or shrubby herbs with cuneate to obovate leaves with a notched apex with a central tooth (extension of the midrib). The leaves are otherwise entire or have a few apical teeth (Fig. 1). The flowers are subsessile or shortly pedicelled, solitary in the leaf-axils and usually also congested into terminal heads. The corolla is pale yellow to orange, often with reddish veins. The fruit consists of five mericarps.