Robert Clarke is a renowned figure in the history of cannabis and is considered one of the leading experts in the field of ethnobotany and cannabis genetics. He has dedicated much of his life to the study of cannabis and its history, cultivation, and uses across different cultures.

Robert Clarke's work has focused on researching the botanical aspects of cannabis, including its taxonomy, breeding, and genetic diversity. He has traveled extensively to various regions where cannabis has been traditionally used, such as South Asia, the Middle East, and Africa, to study the plant's historical and cultural significance.

As an ethnobotanist, Robert Clarke has been instrumental in shedding light on the long history of cannabis as a medicinal, recreational, and industrial plant. He has authored and co-authored several books on cannabis, including "Marijuana Botany" which has become a seminal resource for cannabis enthusiasts, cultivators, and researchers.

Throughout his career, Robert Clarke has been an advocate for the responsible use of cannabis and has sought to dispel myths and misconceptions surrounding the plant. His expertise and contributions have played a significant role in advancing our understanding of cannabis and its place in human history and culture.