Kratom (Mitragyna speciosa) is an evergreen tree that can grow to a height of 25 m (82 ft) tall and the trunk may grow to a 0.9 m (3 ft) diameter.[17] The trunk is generally straight and the outer bark is smooth and grey. Mitragyna Speciosa is indigenous to Thailand, Indonesia, Malaysia, Myanmar, and Papua New Guinea. Ingredients: Mitragynine Speciosa.