Herbs annual or perennial, rarely ± shrubby, usually succulent, usually glabrous except for nodal hairs and/or scales. Leaves alternate or opposite; true stipules absent, nodes sometimes with axillary scales and/or hairs; petiole usually poorly defined or absent; leaf blade simple, usually fleshy, margin entire. Inflorescences usually terminal, less often axillary, in cymes or racemelike panicles, forming heads of sessile flowers surrounded by an involucre of leaves, or reduced to solitary flowers. Bracts inconspicuous. Flowers bisexual, very rarely unisexual, actinomorphic. Sepals 2, free or basally connate, herbaceous or scarious. Petals 4-6 or seldom more, distinct or basally connate, imbricate, often brightly colored, usually short lived. Disk usually absent. Stamens 4-100, free, fascicled, or adnate to petals; filaments linear; anthers 2-loculed, introrse, dehiscence longitudinal. Ovary superior or half-inferior, 1-loculed, 2-5-carpellate; ovules 1 to many, campylotropous; placentation basal or free-central. Style linear; stigma 2-9-lobed. Fruit a thin-walled capsule, circumscissile or 2- or 3-valved, rarely a nut, often globose or subglobose, smooth. Seeds many, reniform or globose, caruncle present or not; endosperm mostly copious, surrounded by embryo.
About 19 genera and 500 species: mainly in more arid regions of S hemisphere, especially Africa, South America, and Australia, fewer species in Asia, Europe, and North America; two genera (one introduced) and six species (two endemic, two introduced) in China.
Lu Dequan. 1996. Portulacaceae. In: Tang Changlin, ed., Fl. Reipubl. Popularis Sin. 26: 36–42.