The leaves of Athanasia flexuosa are about stalkless, spiralling and ascending up the stems that branch mainly near the base. Foliage is either sparse or crowded on the stems.

The narrow, long leaves are linear in shape and about flat, sometimes with slight curving in to the pointed tips. Faint hairiness is present upon the stems and the slightly fleshy young leaves (Bond and Goldblatt, 1984; iNaturalist).