An illegal drug produced from the plant Cannabis sativa. The dried inflorescences of the plant are known as marijuana and the thick resin produced from the plant is known as hashish. The normal method of using cannabis is to smoke it, although it can also be taken in certain foods. Cannabis is a class B controlled substance in the UK. It contains a large number of related compounds known as herbal cannabinoids. The main active component is tetrahydrocannabinol (THC).