Copiously branched, succulent herbs or waterplants. Leaves ovate to linear, occasionally parallel-veined, without axillary hairs. Flowers in axillary and/or terminal cymes or solitary. Petals 5. Stamens 3 or 5; Ovary superior; Fruit pyriform to globular, 3-valved, after dehiscence occasionally twisted. Seeds 1-5.
Australasia: Tasmania (Tasmania present), Central Africa present, Europe present, Mt Kilimanjaro in Central Africa present, N. & S. America present, New Zealand present, Northern Asia present, high mountains of New Guinea present
About 50 spp. Temperate and warm-temperate in Europe, Northern Asia, N. & S. America, Central Africa, and in Tasmania and New Zealand (the present species only!); the sole tropical localities in the Old World are on Mt Kilimanjaro in Central Africa and the high mountains of New Guinea. Generic delimitation, e.g. against Claytonia, is not very satisfactory.