- Mitragyna speciosa (commonly known as kratom, an herbal leaf from a tree of the Rubiaceae family) is a tropical evergreen tree in the coffee family native to Southeast Asia. It is indigenous to Thailand, Indonesia, Malaysia, Myanmar, and Papua New Guinea, where it has been used in herbal medicine since at least the 19th century. It has also historically been used for chewing, smoking, and tea. Kratom has opioid properties and some stimulant-like effects.