Aspects of the taxonomy of Aloe arborescens Mill. (Asphodelaceae: Alooideae)

Abstract

Taxonomic concepts in the morphologically variable Aloe arborescens Mill. are discussed. Previous approaches to the taxonomy of this species varied from describing aberrant material as new entities, using formal taxonomic categories, to selecting forms with horticulturally desirable characters and naming these as cultivare. We propose that in the case of this species, the preferred approach to recognise variation among entities in horticulture should be at the level of cultivars, rather than formal taxonomic entities at infraspecific ranks. It is only after extensive fieldwork throughout the complete distribution range of this species and intensive research, including all possible forms of data (morphological, anatomical, chemical, molecular, etc.), that any formal distinctions at infraspecific level can be made.