A New Combination for a Malawian Peristrophe (Acanthaceae)

Abstract

Some 20 years ago, realising that the syntypes of Dicliptera aculeata C. B. Clarke are in fact referable to Peristrophe and fall into the complex centred on P. paniculata (Forssk.) Brummitt (formerly known as P. bicalyculata (Retz.) Nees), I transferred the material in the Kew herbarium accordingly. However, the combination has not hitherto been published. In the concept of Balkwill (1985) P. paniculata is an annual with a corolla 6-14 mm long. Plants from various parts of tropical Africa which have commonly been referred to this species but are perennials with a corolla 17-27 mm long, often also having their flowers aggregated into rather dense clusters, have apparently to be excluded from P. paniculata. Most distinctive among such plants are those from northern Malawi, including the syntypes of D. aculeata, cited below. The relationship of these to other perennial plants in this complex with less conspicuously aggregated flowers, which occur in the rest of Malawi and elsewhere, remains to be determined. Meanwhile, floristic work requires publication of the appropriate combination in Peristrophe. I am grateful to Dr K. Balkwill for his comments and support.