Petrorhagia
2 species naturalized Aust.; all states and territories except NT
Annual herbs with stiff erect stems, 10–40 cm high. Leaves linear, 1–6 cm long. Flowers small, in terminal head-like clusters, 2–8 per cluster; calyces concealed by broad scarious bracts of which the innermost are 12–15 mm long. Petals pink. Calyx 5-toothed, 5-angled. Stamens 10. Styles 2. Capsule ovoid, 6–8 mm long, opening by 3 teeth. Seeds shield-shaped, hollowed on the inner face.