Herbs perennial or annual, with rhizomes, fibrous roots, or tubers with a vertical stolon below ground. Stem very short, long and erect, or climbing. Leaves basal and rosulate, or alternate, petiolate, with glandular, papillose hairs. Flowers bisexual, actinomorphic. Sepals (4 or)5(or 6-12), free or connate at base, persistent. Petals 5, free, closing and contorted after anthesis, persistent. Stamens as many as petals. Ovary superior, 1-loculed, 2-5-carpellate; placentation parietal; styles (2 or)3-5(or 6), free or connate at base, persistent. Capsule dehiscent, 2-6-valved. Seeds numerous, ellipsoid or linear, sometimes winged.

About 100 species: tropical to tundra regions, especially concentrated in Australia; six species (one endemic) in China.