Commemorating the Swiss family Thomas, several of whom were plant collectors.
Shrubs. Leaves alternate, entire or lobed, stipules mostly 2, leaf-like. Flower clusters opposite the leaves. Bracteoles 3, often shortly fused at the base. Sepals 5, petal-like, purple to blue or white, cut to near the middle, each with 1 thickened midrib. Petals scale-like or absent. Stamens 5, free or shortly united at the base, sterile stamens, when present, 5, shorter than the fertile stamens. Ovary 3(4-5) chambered with 2 or more ovules. Fruit a valvate capsule enclosed in the enlarged dry and often coloured calyx.
Seed and cuttings.
Calyx of 5 petal-like sepals divided to about the middle and each with 1 thickened midrib.
About 32 species from Western Australia with 1 species extending to South Australia and Victoria
Source: (1997). Sterculiaceae. In: . Horticultural Flora of South-eastern Australia. Volume 2. Flowering plants. Dicotyledons. Part 1. The identification of garden and cultivated plants. University of New South Wales Press.