Sacks was a lifelong fern obsessive, and in 2000 he went to Oaxaca with the American Fern Society — a busload of amateur botanists, a few professionals, and him with a notebook. So the book is ferns, but it’s also mezcal and how it’s distilled, chocolate, cochineal insects and the red they make, Monte Albán, the market at Tlacolula, the mathematics of zero as the Zapotecs had it, and a long riff on hallucinogenic mushrooms. He’s at his most relaxed here, traveling with people as monomaniacal as he is, and it’s short enough to read in an afternoon.
Oaxaca Journal