Smith, G. F. “Crassula shanelleae (Crassulaceae Subfam. Crassuloideae), Species Status for C. arborescens Subsp. undulatifolia From the Eastern Cape Province, South Africa”. Phytotaxa, vol. 760, no. 3, June 2026, pp. 217-29, doi:10.11646/phytotaxa.760.3.2.