Herbs or small shrubs. Leaves alternate, whorl-like or in basal rosettes; stipules absent. Flower clusters mostly terminal, branched, occasionally spike-like or solitary. Flowers irregular, bisexual, 5-parted. Calyx of 5 free or 2-lipped lobes. Corolla with a short basal tube of 5 lobes, the lowest lobe smallest. Stamens 2, fused to the style to form a column (the gynostemium). Ovary inferior, incompletely 2-chambered, each chamber of many ovules with axile or freecentral placentation. Fruit a 2-valved capsule containing numerous seeds.
The sensitive column that snaps closed on visiting insects is an unusual pollination mechanism.
One of the petals (labellum) is smaller than the others; style and stamens fused to form a column.
6 genera with about 150 species from Australia, New Zealand, SE Asia and Chile. In Australia there are 4 genera and about 120 species with a centre of distribution in SW WA.
Source: (2002). Stylidiaceae. In: . Horticultural Flora of South-eastern Australia. Volume 4. Flowering plants. Dicotyledons. Part 3. The identification of garden and cultivated plants. University of New South Wales Press.