Aloe arborescens Miller

Aloe arborescens Miller is a tree-forming aloe species, which is native to Southern Africa, appearing throughout the costal and mountainous regions. This species is highly variable and boasts multiple morphological phenotypes, some of which have been established as naturally occurring varieties that are regarded as synonymous with this species. Despite being cultivated and utilised worldwide for its wound healing and purgative effects in South Africa and worldwide, there is limited research that evaluates the pharmacological properties of this plant and among varieties thereof. In addition, isolation studies of identifying biomarkers specifically for this species is limited. However, two Aloe spp. biomarker compounds, aloe-emodin and aloin A, have been previously isolated from A. arborescens. Furthermore, the lack of documentation on the chemical profiling of this species, and groupings thereof, opens new avenues for potential study to better understand the pharmaceutical relevance of this plant. The botanical description, distinguishing characteristics between varieties, geographical distributions, ethnobotanical usage and pharmacological evaluations, of this species has been summarised in this chapter.