Phyllostegia renovans, a member of the Lamiaceae (mint) family, is an erect subshrub when young, becoming scandent at maturity with stems up to 3 to 4 m (9.8 to 13 ft) long. The leaves are narrowly ovate to ovate, sometimes broadly so, at 12.5 to 20 cm (4.9 to 7.9 in) long by 5 to 8.8 cm (2 to 3.5 in) wide. The inflorescences are racemose (simple inflorescence with flowers borne on short stalks and opening from the bottom up), 18 to 34 cm (7 to 13.4 in) long. The corollas are white and about 19 to 22 mm (0.7 to 0.9 in) long. The fruits are greenish black nutlets that are about 8 to 9 mm (0.3 to 0.4 in) long.