Marijuana and hashish, two substances derived from the hemp plant (Cannabis sativa), are also considered natural hallucinogens, although their potency (power) is very low when compared to others. Marijuana (also called grass, pot, tea, weed, or reefer), a green herb from the flower of the hemp plant, is considered a mild hallucinogen. Hashish is marijuana in a more potent, concentrated form. Both drugs are usually smoked. Their effects include a feeling of relaxation, faster heart rate, the sensation that time is passing more slowly, and a greater sense of hearing, taste, touch, and smell.