Cannabaceae is a family of flowering plants that includes the genera Cannabis and Humulus. The genus Cannabis consists of three species, Cannabis sativa, Cannabis indica, and Cannabis ruderalis, which are commonly known as marijuana or hemp. These plants contain psychoactive compounds such as delta-9-tetrahydrocannabinol (THC) and have been used for medicinal, recreational, and industrial purposes for thousands of years. The genus Humulus includes the hop plant, which is used in brewing beer.

The family Cannabaceae is part of the order Rosales, which also includes families such as Rosaceae (roses), Fabaceae (legumes), and Fagaceae (oaks). Plants in this family are typically characterized by their opposite leaves, lack of stipules, and unisexual flowers. The female flowers have a two-lobed ovary and produce seeds enclosed in a dry fruit called an achene. Male flowers have five stamens and produce pollen.

In medical contexts, Cannabis sativa and Cannabis indica are the most commonly used species for medicinal purposes. They contain various cannabinoids, including THC and cannabidiol (CBD), which have been shown to have potential therapeutic effects on a variety of conditions such as chronic pain, nausea, spasticity, and anxiety disorders. However, more research is needed to fully understand the mechanisms of action and potential side effects of these compounds.