Olga Herrera MacBryde, 70, a Smithsonian botanist for more than 20 years and an international conservationist for whom two plant species and a tree are named, died of lung cancer April 22 at her home in Fairfax City, Va.

Ms. Herrera MacBryde spent a decade in the Smithsonian's botany department, working as scientific coordinator, editor and sometimes co-author of more than 60 chapters of the 1997 volume of Centres of Plant Diversity, a geographic review of Earth's biologically rich sites. She specialized in areas of Mexico through South America.

She was editor of a bilingual report on the Mayan forest in Mexico and Central America and primary editor of a book on biodiversity, local communities, conservation and management for the Beni Biosphere Reserve region in northern tropical Bolivia. She was also the Spanish editor for the translation of a book on methods to monitor the biodiversity of frogs and other amphibians.

Two Ecuadoran plant species are named after her and her husband, and the tree Psychotria olgae in Chagres National Park in Panama is named in recognition of her work.

A native of Guayaquil, Ecuador, she conducted her taxonomic research at the Missouri Botanical Garden, where she met her husband, a botanist.

From 1970 to 1972, she chaired and taught in the biology department of Pontificia Universidad Catolica del Ecuador in Quito.

From 1972 to 1975, the family lived in Canada, where Ms. Herrera MacBryde was a research assistant for the first comprehensive book and computer database on the wild plants of British Columbia, and she co-authored a bilingual book on weeds of Central America. - Washington Post