Smith, Gideon F. 2026. “Crassula shanelleae (Crassulaceae Subfam. Crassuloideae), Species Status for C. arborescens Subsp. undulatifolia From the Eastern Cape Province, South Africa”. Phytotaxa 760 (3). Auckland, New Zealand:217-29. https://doi.org/10.11646/phytotaxa.760.3.2.