The green, pointed dorsal sepal of Habenaria transvaalensis is shallowly helmet-shaped and ridged. The pair of lateral sepals are oblique at the base, twisting and pointed.
The white petals are bilobed, their short upper lobes adhering to the dorsal sepal flanks, while the linear lower lobes grow larger, spreading and curving to their tapering tips.
The tripartite lip is white, its median lobe descending; the larger lateral ones sometimes deflexed. In the photo the lateral lip lobes are nearly parallel to the lower petal lobes. The curved spur from below the lip becomes up to 2,8 cm long, its tip inflated into a club-shape.
The anther thecae on the sides of the rostellum are thinly cylindrical, the stigmatic processes club-shaped with base against the lip.
Flowering happens in summer, mainly midsummer (www.africanorchids.dk; www.orchidspecies.com).