Uncaria is a genus of flowering plants in the family Rubiaceae. It has about 40 species. Their distribution is pantropical, with most species native to tropical Asia, three from Africa and the Mediterranean and two from the neotropics. They are known colloquially as gambier, cat's claw or uña de gato. The latter two names are shared with several other plants. The type species for the genus is Uncaria guianensis. Uncaria is a member of the tribe Nauclea, but its position within that tribe remains unresolved.