Erect or trailing, usually perennial herb up to 120 cm tall, pubescent; stem often woody at base. Leaves opposite, simple; petiole up to 1.5 cm long; blade ovate-lanceolate, up to 8 cm × 3 cm. Inflorescence a dense terminal spike up to 20 cm long, continuous or interrupted in the basal part; bracts linear-lanceolate. Flowers bisexual, c. 1 cm long, bright yellow; sepals 5, c. 3 mm long, white hairy; corolla tubular, 2-lipped, lower lip 2-lobed, upper lip 3-lobed; stamens 2, filaments glabrous, one anther cell below the other, tailed; ovary superior, 2-celled, subglabrous, style hairy below, ending in 2 short stigma branches. Fruit a 4-seeded capsule c. 8 mm long, densely hairy, splitting in 2 halves, but remaining connected at base. Seeds compressed globose, brown to black.

Emetic and haemostatic (leaves)

PROTAbase: Justicia flava

Certain preparations are used on cuts and to treat menorrhagia, and blood in the sputum. The whole crushed plant, mixed with vegetable ash, seed of Aframomum species and capsicum pepper is administered by enema against painful menses, or, mixed with lemon juice, taken to induce menstruation. The pulped leaves are rubbed on the skin to treat convulsions and feverish pains in babies. The plant is used internally and externally against fever, yaws and diarrhoea in children. The inflorescence is said to be a cure for dysentery. An infusion of the plant is taken with egg albumen and coconut juice against palpitations of the heart and leaf sap is used as an eye lotion. The leaf sap is taken against hookworm and to treat hydrocele, including bathing the affected parts. The bitter root is chewed to cure diarrhoea and coughs.