As this project expanded in scope, the debts I accrued also increased.
Although I cannot acknowledge here everyone who helped, inspired,
or questioned this book, I wish to express my gratitude to those who
most influenced my thought process.
In particular, for their intellectual guidance and mentorship, I
thank Warwick Anderson, Eric Van Young, Dain Borges, Charles
Briggs, and Carlos Vélez-Ibáñez.
I can never suﬃciently thank the dozens of rural Mexicans who
set their work aside to respond to my questions about barbasco, but
I can state here that the stories they shared, which were crucial for
this book, are what allowed me to obtain fellowships, grants, and my
current job. While I cannot name them all, the most important inter-
views are listed at the beginning of the bibliography. I am particularly
thankful to Isidro Apolinar of Chiltepec, Oaxaca, and his family who
welcomed me, often for several hours at a time over the span of ﬁve
years. Indeed, this book would be a very diﬀerent one if it weren’t for
the time that dozens of individuals, such as Don Isidro, gave to me at
diﬀerent stages of this book’s production.
I am extremely grateful to the Mexican scientists who patiently ex-
plained chemistry, botany, and biology in terms that a historian could
grasp. While I cannot list them all here, I am indebted to Dr. Ricardo
Reyes Chilpa and his graduate students at the Institute of Chemis-
try at UNAM, Maestra Abigail Aguilar and her incredible research
team at the Herbario IMSS (Instituto Mexicano del Seguro Social) in
Mexico City, Dr. Alfredo Pérez Jiménez of the Institute of Biology at
UNAM, Ing. Carlos Huerta at Universidad Autónoma de Chapingo,