1. Department of Life Sciences Natural History Museum London SW7 5BD UK
2. Key Laboratory of Southern Subtropical Plant Diversity Fairylake Botanical Garden, Shenzhen & The Chinese Academy of Sciences Shenzhen 518004 P. R. China
3. Jodrell Laboratory Royal Botanic Gardens Kew Richmond Surrey TW8 3DS UK
4. School of Biological and Chemical Sciences Queen Mary University of London London E1 4NS UK