SWANEPOEL, W.; BECKER, R. W.; WYK, A. E. V. Petalidium engoense (Acanthaceae), a new species from Angola and Namibia, with notes on phenotypic plasticity in the genus. Phytotaxa, Auckland, New Zealand, v. 734, n. 1, p. 9–19, 2025. DOI: 10.11646/phytotaxa.734.1.2. Disponível em: https://phytotaxa.mapress.com/pt/article/view/phytotaxa.734.1.2. Acesso em: 17 dec. 2025.