What is in a name? Scientific name changes of potentially poisonous plants and fungi in South Africa

Changes over the past five decades in the scientific names of some potentially poisonous plants and toxigenic fungi in South Africa are briefly reviewed. Some of the reasons why taxonomists change names are highlighted. In recent years, DNA sequencing data have contributed considerably towards establishing phylogenetic relationships among plants, often resulting in changes in generic circumscription and, consequently, the names of species. Philosophical differences between the phylogenetic and the evolutionary schools of plant classification are briefly explained as these may manifest as different classifications for the same group of plants. Although choice of classification remains the prerogative of the end-user of plant names, in this review, the classifications for plants currently adopted by the South African National Biodiversity Institute (SANBI) in its online database, Plants of Southern Africa (POSA), were followed. Noteworthy generic changes include Pachystigma to Vangueria, Homeria to Moraea, and Urginia to Drimia. Following much controversy, the species native to southern Africa that were formerly treated as Acacia are now classified in either Vachellia or Senegalia, with the genus name Acacia being retained for the mainly Australian members of the group, the latter commonly known as wattles. Former southern African members of Acacia implicated in poisoning include Vachellia erioloba (camel thorn), Vachellia sieberiana var. woodii (paperbark thorn), and Senegalia caffra (common hook thorn).