Sprawling, evergreen shrub. Leaves opposite, to about 11 cm long, elliptic, pointed, glossy; margin wavy-toothed. Flower clusters terminal, open; late spring to early summer. Calyx with 5 deeply cut lobes. Flower tube campanulate with 5 large, spreading lobes, pale violet with dark pencil lines. Stamens 4, 2 fertile, each with 2 anther chambers, 2 sterile. Ovary with 2 chambers, each with 2 ovules. Fruit a longstalked, oblong capsule containing 2 ridged seeds. [Asystasia bella Benth. & Hook.]
This is the sole species in the genus and is grown for its attractive flowers and steady growth in dry shade.
Source: (2002). Acanthaceae. 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.