Ynes Mexia: Botanist And Adventurer (ISBN 1931798672)

It refutes the common notion that great scientists began early on in life:
Ynes Mexia was fifty years old and stuck in an unhappy marriage on a ranch in Mexico when she suffered a nervous breakdown, was sent to San Francisco for treatment, and joined the environmentalist movement there. Her study of botany and series of expeditions throughout South America when she was into her senior years makes for quite a different biography in Durlynn Anema's Ynes Mexia: Botanist And Adventurer: it refutes the common notion that great scientists began early on in life.