The medicinal plants of Myanmar Author DeFilipps, Robert A. Deceased Author Krupnick, Gary A. https://orcid.org/0000-0002-1357-4826 Department of Botany, National Museum of Natural History, Smithsonian Institution, PO Box 37012, MRC- 166, Washington, DC, 20013 - 7012, USA krupnick@si.edu text PhytoKeys 2018 2018-06-28 102 1 341 http://dx.doi.org/10.3897/phytokeys.102.24380 journal article http://dx.doi.org/10.3897/phytokeys.102.24380 1314-2003-102-1 AA226A35FFF8FFBC37621A40C2518C67 1306325 Mitragyna speciosa (Korth.) Havil. Names. Myanmar : bein-sa . English : kratom. Range. Native to Southeast Asia. In Myanmar, found in Chin and Taninthayi. Use. Leaf : used to induce stupor. Notes. In Thailand chewed leaves are reputed to act as a stimulant to help person endure fatigue and long-lasting periods without food. It is also used as an opium substitute, "but is habit-forming" ( Perry 1980 ). On the Malay Peninsula, in addition to chewing the leaves or drinking an infusion, the residue is dehydrated and smoked; all have the same effect ( Perry 1980 ). The leaves, heated with those of Morinda citrifolia , Blumea balsamifera , and Oroxylum indicum , are applied hot to an enlarged spleen; pounded leaves are used as a poultice for wounds or to expel worms from children ( Perry 1980 ). Reported chemical constituents include mitragynine and mitraphylline; the former is said to be a local anesthetic ( Perry 1980 ). Reference. Perry (1980) .