Schiedea trinervis, a member of the pink family (Caryophyllaceae) and a short-lived perennial, is a erect, branched subshrub 0.3 to 0.8 m (1 to 2.6 ft) tall, and glabrous. Leaves are somewhat fleshy and chartaceous when dry, elliptic-ovate or sometimes oblanceolate and 6 to 12 cm (2 to 5 in) long and 3 to 5 cm (1.1 to 2.0 in) wide. Flowers are usually 12 to 20 in open, compound cymes. Secondary and tertiary branches are nearly as long, and pedicels are thinner. Capsules are ovoid to subglobose, 8 to 12 mm (0.3 to 0.5 in) long. Seeds are 1 to 1.5 mm (0.04 to 0.06 in) long. It is very similar in appearance to S. obovata but differs in that it has a more open inflorescence with peduncles more than 2 cm (0.8 in) long and sepals with an acute tip.