Phytotaxa 418 (3): 237–257 ISSN 1179-3155 (print edition) https://www.mapress.com/j/pt/ PHYTOTAXA Copyright © 2019 Magnolia Press Article ISSN 1179-3163 (online edition) https://doi.org/10.11646/phytotaxa.418.3.1 Taxonomic revision of South African Memecylon (Melastomataceae—Olisbeoideae), including three new species ROBERT DOUGLAS STONE1, IMERCIA GRACIOUS MONA2, DAVID STYLES3, JOHN BURROWS4 & SYD RAMDHANI5 1School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg 3209, South Africa;
[email protected] 2,5School of Life Sciences, University of KwaZulu-Natal, Durban 4000, South Africa;
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[email protected] 327A Regina Road, Umbilo, Durban 4001, South Africa;
[email protected] 4Buffelskloof Nature Reserve Herbarium, Lydenburg, South Africa;
[email protected] Abstract Earlier works recognised two South African species Memecylon bachmannii and M. natalense within M. sect. Buxifolia, but recent molecular analyses have revealed that M. natalense as previously circumscribed is not monophyletic and includes several geographically outlying populations warranting treatment as distinct taxa. In this revision we recognise five endemic South African species of which M. bachmannii and M. natalense are both maintained but with narrower circumscriptions, and M. kosiense, M. soutpansbergense and M. australissimum are newly described. Memecylon kosiense is localised in north-eastern KwaZulu-Natal (Maputaland) and is closely related to M. incisilobum of southern Mozambique. Memecylon soutpansbergense, from Limpopo Province, was previously confused with M. natalense but is clearly distinguished on vegetative characters. Memecylon australissimum occurs in the Eastern Cape (Hluleka and Dwesa-Cwebe nature reserves) and has relatively small leaves like those of M. natalense, but the floral bracteoles are persistent and the fruit is ovoid as in M.