Wade Davis has written a lyrical, meticulously researched book of discovery. One River is both a biography of his mentor, the director of the Harvard botanical museum Richard Schultes, and the story of his own botanical adventures throughout South America with colleague Tim Plowman. It's a sprawling tale of explorers, botanical secrets, and larger-than-life personalities. This unconventional book is, in part, a testimonial to Schultes, a legendary teacher and explorer who single-handedly created the discipline of ethnobotany. More than that, it's a magnificently written chronicle of five decades of botanical exploration (including some pretty wild experiments with native hallucinogens).  (AMZ22, $18.00)