1. Departamento de Botânica, Centro de Ciências Biológicas, Universidade Federal de Pernambuco, Recife–PE, and the University Herbarium, University of California, Berkeley, CA 94720‐2465 USA; Present address: Centro de Ciencias Medioambientales, CSIC, Calle Serrano 115 bis, E–28006 Madrid, Spain;
2. Department of Botany, The Field Museum, 1400 South Lake Shore Drive, Chicago, IL 60605‐2496 USA