The genus Petopentia (Periplocaceae)

A taxonomic–morphological treatment of the monotypic genus Petopentia Bullock is presented. Petopentia natalensis (Schltr.) Bullock occurs in the subtropical southern African forests of Natal and Transkei. It is a liana with very characteristic hemispherical above-ground root tubers, elliptic and parallel-veined leaves, pale green-yellowish flowers which have terete corona lobes, and unusual linear- or T-shaped pollen tetrads. The flowers of P. natalensis are basically similar to those of Periploca Decne., Tacazzea Decne., Sarcorrhiza Bullock, Schlechterella K. Schum. and Zacateza Bullock, all tropical African genera. Zacateza and Periploca are probably the closest living relatives of Petopentia