It has square, light green, later pale yellow branchlets, which are initially covered in dense, short, white hairs, which are lost in the older, cylindrical branches.

The file to eight sepals are whitish in color and fused into a closed tube with short white velvet hair on both surfaces.

Sixty to seventy free stamens are 14–20 mm (0.55–0.79 in) long and carry ovate anthers which open with longitudinal slits.

The ovary is linear, 1–1½ cm (0.4–0.6 in) long, towards the tip with four to six grooves and ridges, and four to six compartments, in each of which are two rows of ovules attached to the axis at the centre.

When ripe, the walls of the fruits are shed in longitudinal strips starting from the base, showing the axis with eight to twelve rows of 2–3 mm (0.079–0.118 in) large, initially red, later red-brown kidney-shaped seeds.

[1] Borthwickia trifoliata has been described by the Scottish botanist and horticulturalist William Wright Smith in 1911, who thought it to be closely related to Ritchiea, a member of the caper family.