Karis, P.O. and Mckenzie, R.J. 2024. Second-step lectotypification of Stobaea rigida and reassessment of heterotypic synonyms of Berkheya rigida (Asteraceae, Arctotideae). Phytotaxa. 641, 4 (Mar. 2024), 267–276. DOI:https://doi.org/10.11646/phytotaxa.641.4.3.