thorelii (Pierre) C. Phengklai is an accepted name according to the Catalogue of Life and found in Vietnam, where it is known as bảy thưa Thorel.

[5] The gum karaya is a medium-sized deciduous tree with horizontally-spreading branches, growing to a maximum height of about 15 m (49 ft).

The bark is smooth, fibrous and thick, greenish-grey, with the surface layer peeling off in large flakes.

They are polygamous (having male, female and bisexual flowers on the same tree) and are clad in sticky or glandular short hairs.

This valuable substance is traditionally tapped by cutting or peeling back the bark, or by making deep gashes at the base of the trunk with an axe.

[7] Karaya gum swells when it absorbs water and is used as a laxative because adds bulk to the contents of the intestine, stimulating the gut to expel waste material.