Mitragyna speciosa

What is Mitragyna speciosa?

Mitragyna speciosa is an evergreen tropical tree in the Rubiaceae plant family - the same family as coffee (Coffea) and quinine-bearing Cinchona. It was first scientifically described by the Dutch botanist Pieter Korthals in 1839 under the genus Stephegyne, and was later transferred to Mitragyna by George Darby Haviland in 1897. The genus name Mitragyna refers to the mitre-like (bishop's-hat-like) shape of the stigma in the flowers.

In its native range the species grows as a tall tree reaching up to roughly twenty-five meters in mature wild specimens. The leaves - large, glossy, and elliptical - are the plant part historically harvested for the alkaloids that have made the species the subject of contemporary scientific and regulatory attention.

Where is Mitragyna speciosa native?

The species is endemic to Southeast Asia. Its established native range covers Thailand, Malaysia, Indonesia (especially Sumatra, Borneo, and West Papua), Borneo broadly, and Papua New Guinea. Commercial cultivation today is concentrated in West Kalimantan and other Indonesian provinces, where exports of dried leaf and powder supply much of the global kratom market. The plant also grows in cultivated and naturalized populations elsewhere in tropical Asia.

Alkaloid chemistry of the leaf

Over forty alkaloids have been identified in Mitragyna speciosa leaves. The dominant constituent is mitragynine, typically representing 50-66% of total leaf alkaloid content depending on strain, harvest, and processing. Secondary alkaloids include paynantheine, speciogynine, speciociliatine, corynantheidine, corynoxine, corynoxeine, and more. 7-Hydroxymitragynine occurs only in trace amounts in fresh leaf and is more relevant as the active hepatic metabolite of mitragynine via CYP3A4.

Most kratom alkaloids belong to the indole alkaloid family, specifically the corynantheine subclass. The pharmacology of these alkaloids - particularly their interactions with opioid, adrenergic, and serotonergic receptors in laboratory assays - is the subject of an active and growing peer-reviewed research literature.

Historical and ethnobotanical context

Kratom has a documented history of traditional ethnobotanical use in Southeast Asia. Researchers have catalogued historical practices dating back well over a century. Modern phytochemical and pharmacological investigation began in the early twentieth century in Europe, with sustained pharmacology research continuing in Japan in the 1960s and 1970s, and broad international scientific attention from the 2000s forward.

This page describes the species in a research and educational context. It does not provide consumer-use guidance for kratom or any of its alkaloids. For regulatory information specific to 7-hydroxymitragynine and kratom in the United States, see the related glossary entries.