Marijuana is a dioecious plant meaning it has male and female plants. The female plant produces the flowers that are harvested for the production of medicines and recreational drugs. The male plants pollen is harvested and used to pollinate the female plants. The female plants are harvested when they are in the flowering stage. The cannabis plant produces THC (Tetrahydrocannabinol), which is the active ingredient in Marijuana and has been used as a medicinal drug for thousands of years.