English: Kratom; Kakuam; Thom; Ithang.
Clades: Rubiaceae.
Reagion: Southeast Asia; Cambodia, Thailand, Indonesia, Malaysia, Myanmar, Papua New Guinea.
Content: 50 alkaloids; teteacyclic indol alkaloids: mitragynine, 7-hydroxymitragynine; raubasine; speciociliatine, paynantheine, corynantheidine, speciogynine, mitraphylline, rhynchophylline, mitralactonal, raubasine, and mitragynaline; paynantheine, speciociliatine, corynantheidine, corynoxeine, corynoxine B,speciofoline; saponins, iridoids, monoterpenoids, triterpenoids, ursolic acid, oleanic acid; various polyphenols; flavonoids, apigenin, quercetin.
Use: herbal medicine; drug, stimulating, opium like, via chewing, smoking, tea.

BotanyTree; tropical; evergreen; 25 m tall.
Stem: up to 1 m diameter; straight; bark smooth and grey.
Leaves: dark green; glossy; oval-acuminate; opposite; 14 to 20 cm long, 7 to 12 cm wide; 12 to 17 pairs of veins.
Inflorescences: spherical clusters of three; at the ends of the branches
Flowers: deep yellow; globular; calyx-tube is 2 mm long and has five lobes; corolla-tube is 3 mm long.