The native and naturalised species of Peltocalathos and Ranunculus (Ranunculaceae: Ranunculeae) in southern Africa

Abstract

The five native and naturalised species of Ranunculus L. and Peltocalathos Tamaru (Ranunculaceae: Ranunculeae) from
southern Africa are reviewed, with full descriptions and nomenclature, taxonomic history, ecological notes, and distribution
data. All species are illustrated. Peltocalathos, a monotypic genus based on R. baurii MacOwan, has been overlooked in the
regional literature until now. The new name R. dregei J.C.Manning & Goldblatt is proposed as a replacement name for the
later homonym R. meyeri Harv., non Lowe. We conclude that the poorly known R. capensis Thunb. represents juvenile forms
of the widespread and variable R. multifidus Forssk. and we synonymise the name, along with the three trivial epithets R.
pinnatus var. hermannii DC., R. pubescens var. glabrescens Burtt Davy and R. pubescens var. harveyanus Burtt Davy, which
have been overlooked in the recent literature. Based on number (mostly < 40 achenes per head) and size (mostly 1.2–1.8 mm
long) of achenes, we conclude that the southern African material of the aquatic species recently re-identified as R. rionii Lagger
is more appropriately treated as R. trichophyllus Chaix.