Herbs, annual, biennial, or perennial; taprooted or rhizomatous, sometimes stoloniferous. Stems erect or ascending, seldom sprawling, decumbent, or prostrate, simple or branched. Leaves opposite, rarely whorled, connate proximally, petiolate (basal leaves) or often sessile, not stipulate; blade linear or subulate to ovate, not succulent or rarely so (Silene). Inflorescences terminal cymes, thyrses, fascicles, or capitula, or flowers solitary, axillary; bracts foliaceous, scarious, or absent; involucel bracteoles present or often absent. Pedicels present or rarely flowers sessile or subsessile. Flowers bisexual or seldom unisexual (the species then often dioecious), often conspicuous; perianth and androecium hypogynous; sepals 5, connate (1/4–)1/2+ their lengths into cup or tube, (1–)5–40(–62) mm, apex not hooded or awned; petals absent or 5, often showy, white to pink or red, usually clawed, auricles absent or sometimes present, coronal appendages sometimes present, blade apex entire or emarginate to 2-fid, sometimes dentate to lacinate; stamens (5 or) 10 (absent in pistillate flowers), in 1 or 2 whorls, arising from base of ovary; staminodes absent or rarely 1–10; ovary 1-locular, sometimes 2-locular proximally (Vaccaria), or 3–5-locular (some Silene); styles 2–3(–5) (absent in staminate flowers), distinct; stigmas 2–3(–5) (absent in staminate flowers). Fruits capsules, opening by 4–6(–10) valves or teeth; carpophore usually present. Seeds 4–150(–500+), reddish to gray or often brown or black, usually reniform and laterally compressed to globose, sometimes oblong or shield-shaped and dorsiventrally compressed; embryo peripheral and curved, or central and straight. x = 7, 10, 12, [13?,] 14, 15, 17, [18].