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