The Montiaceae family is represented in Tasmania by two genera. The Montia species are semi aquatic herbs with flowers of 5 free petals and 5 stamens. The Calandrinia species are herbs which grow in dry places. They have flowers with 4-7 free petals (usually 5) and numerous stamens. The plants have more or less succulent leaves and symmetrical flowers with 2 sepals.

The Portulacaceae family has two introduced species. The plants have more or less succulent leaves and small symmetrical flowers with 2 sepals and 4-6 petals (all free).