Which portion of the Marijuana plant produces the psychoactive substance known as THC?

The story behind the answer

Female flowers (the “buds”) produce most of the plant’s THC because they’re covered in resin-secreting glandular trichomes. These tiny, mushroom-shaped structures synthesize and store cannabinoids like THC, along with aromatic terpenes. Leaves may have some trichomes but at much lower density; male flowers and roots contain little to no THC.

Why make THC at all? It’s a protective chemical: the sticky resin helps defend against herbivores, pathogens, and UV radiation. Memory tip: “THC = The High Comes from the buds”—and buds are the female flowers.