Smith, G.F. 2024. A reassessment of variation in Kalanchoe gastonis-bonnieri (Crassulaceae subfam. Cotyledonoideae), a pseudo-rosulate species from Madagascar: reinstatement of K. adolphi-engleri at the rank of varietas under K. gastonis-bonnieri. Phytotaxa. 672, 3 (Nov. 2024), 277–284. DOI:https://doi.org/10.11646/phytotaxa.672.3.5.