Perennial herbs; stems decumbent. Leaves alternate, cauline, petiolate. Inflorescences mostly of solitary flowers arising from stems just below unreduced leaves, sometimes also axillary or terminal bracteate monochasial cymes. Flowers long-pedicellate; sepals 5, connate basally, elongating slightly in fruit; corolla regular, 5-lobed, more or less funnel-shaped, with spreading lobes, scales in throat saccate; stamens included in corolla-tube, anthers more or less sessile, each with a short acute appendage; ovary 4-lobed, 4-celled, style short, stigma capitate. Fruit splitting into 4 mericarps, leaving a low convex gynobase; mericarps densely covered with more or less equal barbed spines.
Monotypic genus endemic to Australia.