Swanepoel, W., Dexter, K.G., Adamo, M., Manzitto-Tripp, E.A. & van Wyk, A.E. (2025) Petalidium saxatile (Acanthaceae), a new species from Namibia. Phytotaxa 716 (3): 161–174. https://doi.org/10.11646/phytotaxa.716.3.1