Olwen M. Grace is a botanist at the Royal Botanic Gardens, Kew.Ronell R. Klopper is a plant taxonomist and manager of the Aloes of the World Project at the South African National Biodiversity Institute.Estrela Figueiredo is a plant taxonomist and research associate at the Department of Botany, Nelson Mandela Metropolitan University, in South Africa.Gideon F. Smith is Chief Director for Biosystematics Research and Biodiversity Collections at the South African National Biodiversity Institute.