Capitate-stalked trichomes are the primary site of cannabinoid and terpene biosynthesis in cannabis. These specialized epidermal structures feature a multicellular stalk topped by a secretory head composed of disc cells that synthesize and accumulate cannabinoids, terpenes, and flavonoids in a subcuticular storage cavity. Trichome density varies dramatically between landrace populations, correlating with environmental pressures such as UV radiation intensity, herbivory pressure, and water stress.
Highland varieties from regions like the Hindu Kush and Western Himalayas often display exceptionally dense trichome coverage with high resin production, reflecting adaptation to intense solar radiation at high elevations. Lowland tropical varieties may show sparser but larger trichomes optimized for different environmental conditions. The chemical profile of trichome secretions also varies regionally—some populations produce predominantly THC, others CBD, while many landrace varieties maintain balanced cannabinoid ratios reflecting thousands of years of selection for traditional uses.
