A student in Brazil (I don't remember who) asked for references about
nectar and polen plants. There is a new book, about urban plants,in portuguese:
Jose Rubens Pirani & Marilda Cortopassi-Laurino (eds.). 1993. Flores e Abelhas
em Sao Paulo. EDUSP, Sao Paulo, 192 p.
Hope this help.
Celso F. Martins
Dep. Sistematica e Ecologia CCEN
Universidade Federal da Paraiba
Joao Pessoa PB Brasil
58059-900
Email: [log in to unmask]