Since childhood, Oliver Sacks has been fascinated by ferns: an ancient class of plants able to survive and adapt in many climates. Along with a delightful group of fellow fern aficionados—mathematicians, poets, artists, and assorted botanists and birders—he embarks on an exploration of Southern Mexico, a region that is also rich in human history and culture. He muses on the origins of chocolate and mescal, pre-Columbian culture and hallucinogens, the vibrant sights and sounds of the marketplace, and the peculiar passions of botanists. What other species would comb ancient Zapotec ruins on their hands and knees, searching for a new type of fern? Combining Sacks's enthusiasm for natural history and the richness of humanity with his sharp and observant eye for detail, Oaxaca Journal is a rare treat.