Ozoroa engleri, the drooping resin-tree, weeping resin-tree or white resin-tree, in Afrikaans the treurharpuisboom (grieving resin tree) and previously Heeria insignis, is a robust shrub of 4 m or small tree with spreading crown up to 8 m in height (SA Tree List. No. 371).
It has rough, dark brown or grey bark that later flakes in square patches or becomes cracked on the often crooked stem. The latex is thin and watery, in some resin trees milky and resinous, bringing the genus the resin-tree name.
The simple leaves, here alternate, are often whorled in threes. The leaves droop more or less on hairy petioles of 1 cm to 3 cm, variously coloured pinkish brown, yellowish or grey. The leaf-shape is elliptic to oblong, tapering to a hair-tipped apex and tapering to the base. The margins are entire, the midrib prominent below and recessed above.
The closely spaced, parallel lateral veins are also prominent below, about straight to the slightly thickened, slightly wavy margins. The thinly textured, bicoloured blades are folded in along the midribs, grey-green above, silvery on the lower surfaces from dense, flat-lying hairs. Leaf dimensions are 4 cm to 14 cm long and 1 cm to 3,3 cm wide. The leaves are browsed by game and stock.
The species only occurs in the far northeast of South Africa, in Limpopo, Mpumalanga and KwaZulu-Natal, as well as beyond the border in southern Africa.
The habitat is open bushveld at lower elevations on dry sandy flats and rocky slopes. The species is not considered to be threatened in its habitat early in the twenty first century.
The leaves and roots are used medicinally (Coates Palgrave, 2002; Schmidt, et al, 2002; Van Wyk and Van Wyk, 1997; Pooley, 1993; iNaturalist; http://redlist.sanbi.org).