During his long career, Oliver Sacks was first and foremost known as an explorer of the human mind, a neurologist with a knack for complex and insightful portraits of people and their illnesses that spurred on the phenomenal success of his books. But he was also an active member of the American Fern Society, and as a child he was always fascinated by the ability of these primitive plants to survive and adapt to diverse climates. In Diario de Oaxaca, he intelligently weaves the colorful threads of biology, history and culture to weave a fascinating tapestry from Mexico and a group of fern hunters united by a common passion.