The Hindu Kush-Himalayan regional complex represents one of the world's most important centers of landrace cannabis diversity, spanning Afghanistan, Pakistan, India, Nepal, and Bhutan. This massive mountain system creates extreme environmental gradients from subtropical river valleys below 1000m to high-altitude cultivation zones exceeding 3500m elevation, driving extraordinary morphological and chemical diversification in local populations.
The complex includes major growing regions like the Western Himalayas (Parvati Valley, Kullu Valley), Kashmir Valley, Chitral, and numerous valleys throughout the Hindu Kush where traditional charas production has occurred for centuries. Altitude-driven environmental variation creates distinct ecotypes—lowland populations with longer flowering times and taller stature versus compact, early-flowering highland types adapted to short growing seasons and intense UV radiation. The orographic effect of these mountains creates dramatic rainfall gradients, with windward slopes receiving abundant monsoon moisture while leeward rain-shadow zones remain arid, further diversifying cultivation environments and traditional varieties.
