Spreading annual forb to 10cm tall. Leaves alternating along the stems or opposite each other. Leaves 1.1-1.5cm long, 2.1-4.1mm wide, flat, hairless, edges slightly curved under, with blunt tips. Male and female flowers on the same plant. Flowers tiny (less than 3mm across) with 5 'petals', male 'petals' white, female 'petals' pink. Flowers in dense rounded clusters at the tops of the stems. Family Euphorbiaceae in SA.
The paper that describes this species maps Poranthera leiosperma as the only species of Poranthera in the area covered by this key.
It differs from Poranthera microphylla in that the leaves are longer (11-15mm long) and the plant is more robust.
Description and line drawings in Halford, D.A. & Henderson, R.J.F. (2005) Studies in Euphorbiaceae, s. lat. 6. A revision of the genus Poranthera Rudge (Antidesmeae, Porantherinae) in Australia. Austrobaileya 7 (1): pages 15-16, Fig. 3, Map 9