1. 2Department of Biology, Coker Hall, University of North Carolina, Chapel Hill, North Carolina 27599 USA;
2. 3Herbarium, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, UK;
3. 4Department of Higher Plant Systematics and Evolution, Institute of Botany, University of Vienna, Rennweg 14, A‐1030 Vienna, Austria;
4. 5Section of Molecular Systematics, Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3DS, UK;
5. 6Rand Afrikaans University, Auckland Park, Johannesburg, 2006, South Africa