1. Unit for Environmental Sciences and Management, Department of Botany, North-West University, Mafikeng, Private Bag X 2046, Mmabatho 2735, South Africa
2. South African National Biodiversity Institute, Pretoria National Botanical Garden, 2 Cussonia Avenue, Brummeria, Silverton 0184, South Africa
3. School of Biology and Environmental Science, Faculty of Agriculture & Natural Science, University of Mpumalanga, Corner R40 and D725 Road, Nelspruit, Mbombela 1200, South Africa
4. Department of Natural Sciences, School of Mathematics, Sciences and Technology Education, North-West University, Mafikeng, Private Bag X 2046, Mmabatho 2735, South Africa
5. Department of Nature Conservation, Mangosuthu University of Technology, Jacobs P.O. Box 12363, Durban 4031, South Africa