The simple, opposite leaves of Nemesia strumosa are narrowly lance-shaped with bluntly pointed to slightly rounded tips. The leaves are stalkless, the bases eared or clasping the stems.
The soft green blades have sunken midribs on their upper surfaces. The margins are slightly and variably toothed (Manning, 2007; Manning and Goldblatt, 1996; Bond and Goldblatt, 1984; iNaturalist; http://pza.sanbi.org).