The leaves of Xenostegia tridentata subsp. angustifolia are alternate, short-stalked and variably spaced along the stems. The petioles (leaf stalks) become 3 mm long. The leaves are long and narrowly lance-shaped or linear with two small, angular or hook-shaped lobes near the base.
The specific name, tridentata, meaning three teeth in Latin, refers to the three rather dissimilar leaf parts. The subspecific name angustifolia, meaning narrow leaves in Latin, tells of the narrowness of the long central lobe.
The dark green upper surface is channelled along its centre, the midrib sunken and keeled below. The leaf is mostly hairless although not very smooth. The leaves become from 2 cm to 8 cm long, only 2 mm to 6 mm wide.
There are some pale green, narrowly conical flower buds visible in the photo as well as a reddish, unripe fruit (Pooley, 1998; iNaturalist; www.zambiaflora.com).