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The journal of the Western Australian Herbarium

Blackallia, Serichonus and Papistylus: three closely related genera of Rhamnaceae (Pomaderreae) from south-western Australia

Recent molecular and morphological studies of Pomaderreae indicate that a number of species that have traditionally been of uncertain affinity require new genera. Blackallia C.A. Gardner is lectotypified and restricted to one species, B. nudiflora (F. Muell.) Rye & Kellermann, for which a new combination is made. Two new genera are described, Serichonus K.R. Thiele comprising the single species S. gracilipes (Diels) K.R. Thiele, and Papistylus Kellermann, Rye & K.R. Thiele with two species, P. grandiflorus (C.A. Gardner) Kellermann, Rye & K.R. Thiele and the new species P. intropubens Rye. All three genera are restricted to the South West Botanical Province of Western Australia. They are closely related but can be readily distinguished from one another by some significant morphological differences, especially in their inflorescences. A revised key to the genera of Pomaderreae is presented and lectotypes are chosen for B. nudiflora and S. gracilipes.