Root single. Thallus floating on water surface, elliptic to rounded or broadly obovate, 1–4 mm long, slightly swollen, green above, if red underneath then reddening beginning from margin, opaque; air spaces in 2 or 3 layers spread throughout thallus, with largest ones mostly longer than 0.3 mm long; veins 3–5, emerging from same point at node; base with stalk indistinct; apex rounded. Colony made up of generations at angles less than 90° to the previous one.
Wim, GleP, Brid, VVP, VRiv, MSB, MuF, GipP, OtP, WaP, Gold, CVU, GGr, DunT, NIS, EGL, HSF, HNF, Strz. Also WA, SA, NSW, Tas. New Zealand.
