Lemna L.
Floating on the surface. Cladodes thick, opaque, broad-ovate to elliptic, 1–4 mm long, stalkless. In still water. Widespread but uncommon in the area. Fl. summer Lemna disperma
Floating beneath the surface. Cladodes thin, translucent, narrow-oblong to lanceolate, 2–8 mm long, stalked when mature. Picton Lakes; Eastlakes. In still water Lemna trisulca