THC Content

"The secretion of THC is most abundant in the flowering heads and surrounding leaves. The amount of resin secreted is influenced by environmental conditions during growth (light, temperature and humidity), sex of the plant, and time of harvest. The THC content varies between parts of the plant: from 10-12 % in flowers, 1-2 % in leaves, 0.1-0.3 % in stalks, to less than 0.03 % in the roots."

Source: 

United Nations Office on Drugs and Crime, "World Drug Report 2009" (Vienna, Austria: United Nations, 2009), p. 97.
http://ahrn.net...

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