The simple leaves of Heteropyxis canescens grow spirally arranged around its stems, or sometimes alternate. They have whitish petioles, about 6 mm long. Trees of the Heteropyxidaceae genus have no leaf stipules.
The leaf shape is narrowly elliptic with narrowly tapering tip, sometimes attenuating into an elongated drip tip. The base tapers. Leaf dimensions are up to 15 cm by 3,5 cm. The margins are entire and rolled under.
Leaf texture is leathery and smooth on top, the colour glossy dark green, while below it is grey hairy and paler green. The whitish midrib is prominent on the lower surface, continuing in likeness into the petiole. The spaced lateral veins, not growing in pairs, ascend and curve in close to the margins, uneven in size. Secondary venation includes tiny, additional lateral veins among irregular net-veins.
The leaves are gland-dotted, while hairy domatia are also present in the axils of the lateral veins.
The small white or cream flowers grow in dense, branched, terminal heads from spring to early autumn. A flower is about 3 mm long, the inflorescence about 2 cm. Flower stalks and young branchlets have a soft grey covering of pale hairs.
The sexes occur on different trees on all species of this dioecious genus. The dehiscent fruit is a pale brown, globose capsule of 3 mm in diameter, partly covered by the calyx (Coates Palgrave, 2002; Schmidt, et al, 2002).