Aloe mutabilis

Aloe mutabilis, sometimes commonly the blue krantz aloe, is closely related to A. arborescens. Some consider it to be just another form of the latter species. There is said to be a form in Mpumalanga bearing pure red flowers, i.e. the perianths do not turn yellow upon opening.

The plant becomes large on few short, basal branches trending sideways. The soft leaves in dense rosettes are glaucous, often shrivelled at their tips once mature. The leaf margins are lightly armed with soft teeth.

The inflorescence is simple, sometimes two-branched. The raceme is conical, the red buds mostly turning yellow when opening and drooping. A raceme is about 1 m tall. Flowering happens in winter.

The species distribution of this South African endemic is in North West from Rustenburg along the Magaliesberg Mountains to Gauteng, eastwards to Belfast (or eMakhazeni) and eMalahleni (Witbank) in Mpumalanga and northwards into Limpopo nearly as far as Polokwane. 

The spectacular feature of this aloe is its capitalising on habitat: clinging to steep cliff edges, hanging high above water and balancing over deep, shady ravines. The species is not considered threatened in habitat early in the twenty first century. 

Should A. mutabilis be left in A. arborescens? The human habit of separating things that display small differences into discrete categories, or conversely, lumping them together when limited similarity is found, has reached into the biological sciences where one species may imperceptibly start to split as parts of its distribution confront different living conditions. Has it happened (yet), or might it happen?

Since Aristotle, categorization has been an important part of scientific output, based on observation and analytical skills. And there are psychological characteristics to distinguish those people who focus on differences from those who focus on similarities. We fortunately also learn how to build conventions and solutions for overcoming every kind of confusion caused by our lifestyle and experience. We call the story of that history (Frandsen, 2017; Van Wyk and Smith, 2003; Jeppe, 1969; iNaturalist; http://redlist.sanbi.org).