Catechu

Catechu is an extract of acacia trees used variously as a food additive, astringent, tannin, and dye. It is extracted from several species of Acacia, but especially Senegalia catechu, by boiling the wood in water and evaporating the resulting brew. The Malay name kachu is the basis of the Latinized catechu chosen as the Linnaean taxonomy name of the plant species which provides the extract.