Shrubs or small trees, glabrous, erect; stems more or less square with 4 prominent ribs. Leaves dimorphic, opposite, decussate; juvenile leaves pinnatisect or pinnatifid; adult leaves serrate or biserrate. Inflorescence terminal and lateral, a simple or compound dichasium in elongated spike; bracts leaf-like, decussate; bracteoles thin, membranous, caducous. Flowers bisexual, cream or red, showy, sessile or pedicellate; sepals 4, small, more or less triangular; petals 4, boat-shaped, sometimes spirally twisted in bud (not in Victoria); stamens 8, anthers linear-oblong, shortly apiculate; ovary 4-celled, glabrous, styles 4. Fruit obovoid to obpyramidal, 4-winged or 4-ribbed, pericarp more or less spongy; seed 1.
5 species, all endemic to Australia.