Quebracho: name for a tanning substance and for the trees from which it comes, chiefly the red quebracho, or quebracho colorado ( Schinopsis lorentzii ), of the family Anacardiaceae ( sumac family).

This hardwood tree, native to the Paraguayan subtropics, supplies one of the most durable and heavy of timbers. It has been used as a source of tanning material for nearly 100 years but has been widely used only in the 20th cent.; today it provides much of the vegetable tannin for the leather industry although the populations are being depleted.

The heartwood, stripped of its bark and subjected to extraction processes, is about 30% tannin. Quebracho is obtained chiefly from wild trees of the forests of the Gran Chaco of Argentina, Paraguay, and Bolivia.