Hemp and marijuana are different varieties of the same species of plant, Cannabis sativa L. They are scientifically different and cultivated in different ways. Hemp is a tall, slender fibrous plant similar to flax or kenaf.
Farmers worldwide have harvested hemp for the past 12,000 years for fiber, food, and oil. Marijuana is the flowering tops and leaves of psychoactive varieties of cannabis that are grown for their high tetrahydrocannabinol (THC) content. Unlike marijuana, hemp contains only small amounts (less than 1%) of the euphoria-producing compound THC and possesses higher percentages of the compound cannabidiol (CBD).
The Controlled Substances Act of 1970, however, does not distinguish between types of cannabis plants and therefore puts growing hemp off-limits despite more than 30 industrialized nations commercially growing hemp, including England and Canada. In 2014, the US Farm Bill agreement included a provision that would allow institutions of higher education and state departments of agriculture to grow or cultivate industrial hemp. Dozens of members of the House and Senate also want to legalize hemp nationwide.