The Silk Road served as the primary corridor for cannabis dispersal across Eurasia for over two millennia, carrying seeds, cultivation knowledge, and consumption traditions from Central Asian origins to China, India, Persia, and eventually the Mediterranean world. Multiple branches of this vast trade network—the steppe route through Kazakhstan and southern Russia, the oasis route through the Taklamakan Desert, the mountain passes through the Pamirs and Hindu Kush—each facilitated distinct patterns of variety movement and regional adaptation.
Archaeological evidence along Silk Road sites reveals cannabis presence at oasis towns like Turpan and mountain waypoints throughout the Pamirs. Chinese historical texts document cannabis fiber and seed trade from at least the Han Dynasty (206 BCE - 220 CE), while Persian and Arabic sources describe hashish consumption spreading westward. The bidirectional flow of goods meant that improved varieties could return to regions of origin, creating complex patterns of genetic exchange. Mountain barriers and desert expanses along the route created natural isolation zones where introduced populations adapted to local conditions, establishing the genetic foundations for many Central and South Asian landraces. The Silk Road's decline in the 15th century CE did not end cannabis dispersal, but shifted routes to maritime trade networks that would carry the plant to Africa and eventually the Americas.
