The nomenclature and taxonomy of Aloe glauca Mill. (Asphodelaceae: Alooideae)

The nomenclature associated with the name Aloe glauca Mill. (Asphodelaceae: Alooideae) is reviewed and analysed. It is shown that in 1768 Philip Miller unambiguously based this name on a plate of A. ferox Mill., and the names A. glauca and A. ferox are therefore synonymous. A previous neotypification of the name A. glauca was redundant as this name has an obligate lectotype. That neotypification is also in serious conflict with important aspects of the protologue. At species rank, A. rhodacantha DC. is the earliest name that was published for what is today widely known as A. glauca. However, we do not propose a change in the nomenclature of this species, pending the outcome of a proposal to conserve the name A. glauca with a conserved type. The names, and their types, included in the synonymy of A. glauca Haw. are clarified. Aloe glauca var. spinosior Haw. is included in the synonymy of A. glauca.