This self-study course offers a plant perspective and integrative insight about a very powerful plant which is legally referred to as “medicinal marijuana.” The course is an introduction to the genus Cannabis (and species such as sativa and indica). It presents a synopsis of the plant’s history and the state of the science that can be used to better understand, interpret, and then inform public and professional exploration, from self-care to traditional use to biomedicine and clinical trials. This course discusses the endocannabinoid system and the new dimensions in the science of physiology that are emerging as a result of the human-plant partnership with marijuana. It also reviews some of the debate regarding the potential social implications for community health related to the increasing alignment of economies, state-by-state, with the promotion of marijuana cultivation, product development, and use for recreational and medicinal purposes.