1. Illinois Natural History Survey; Prairie Research Institute; University of Illinois at Urbana-Champaign; Champaign, Illinois 61820 U.S.A.
2. Department of Plant Biology; University of Illinois at Urbana-Champaign; Urbana, Illinois 61801 U.S.A.
3. Compton Herbarium, South African National Biodiversity Institute; Private Bag X7 Claremont 7735 South Africa
4. Department of Botany and Plant Biotechnology; University of Johannesburg; P.O. Box 524, Auckland Park 2006 Johannesburg South Africa
5. Department of Biology, Harbin Normal University; Hexing Road 50 Harbin 150080 People's Republic of China