Nearly 140 years after botanists categorized cannabis into sativa and indica species, a Russian botanist named D.E. Janichevsky identified a rare cannabis species in 1924 that he called ruderalis. It is the shortest cannabis species, usually reaching only two feet in height, with the least amount of leaves. Ruderalis also contains only small amounts of tetrahydrocannabinol (THC), the cannabinoid responsible for the plant’s psychoactive effects, making it the least-desirable choice for recreational cannabis consumers. As the hardiest of the three species, ruderalis can survive cold temperatures, and Janichevsky actually discovered it in frigid Siberia. In addition to central Russia, the plant also grows in places like the Himalayas and Eastern Europe. Nevertheless, some researchers disagree that ruderalis is a new species and instead argue that it is a hybrid of the other two.