A new species in the tree genus Polyceratocarpus (Annonaceae) from the Udzungwa Mountains of Tanzania

Abstract

Polyceratocarpus askhambryan-iringae, an endemic tree species of Annonaceae from the Udzungwa Mountains of Tanzania, is described and illustrated. The new species is identified as a member of the genus Polyceratocarpus by the combination of staminate and bisexual flowers, axillary inflorescences, subequal outer and inner petals, and multi-seeded monocarps with pitted seeds. From P. scheffleri, with which it has previously been confused, it differs in the longer pedicels, smaller and thinner petals, shorter bracts, and by generally smaller, less curved monocarps that have a clear stipe and usually have fewer seeds. Because P. askhambryan-iringae has a restricted extent of occurrence, area of occupancy, and ongoing degradation of its forest habitat, we recommend classification of it as Endangered (EN) on the IUCN Red List.