PlantFiles: Aloe
Aloe dichotoma x barberae 'Rex'

This is a new fast-growing aloe hybrid from South Africa. It matches the growth habit of its Aloe barberae parentage in speed, size and soil/water preferences while it has the silver/golden flaky bark and blue-green leaves reminiscent of Aloe dichotoma. I have not seen it flower, but I imagine an orange bloom similar to Aloe barberae 'Medusa'. The leaves have pink teeth as opposed to the more yellow teeth typical of A. dichotoma.
A stunning plant if you want to impress other gardeners or if you're an Aloe-phile like me. It differs from actual Aloe 'Hercules' trees I've seen in looks. Their trunks were more grey like A. barberae and their leaves were also longer and greener. However - from other photos of Aloe 'Hercules' I've seen it seems there is some variability in the cross since it refers to any A. dichotoma x A. barberae hybrid in the collective mind of the Aloe growing public and some of these specimens also have more flaky bark and bluer leaves.
The 'Rex' hybrid has been propagated by tissue culture and therefore all the Rex plants look the same. I suppose to avoid any confusion it would be easier to refer to A. dichotoma x A. barberae hybrids as A. 'Hercules' while A. 'Rex' would be a specific hybrid cultivar.
This matter is further complicated by the fact that not all A. dichotoma and A. barberae are and look the same. There are at least three different 'looks' of A. barberae in cultivation in South Africa - two of which are large and one of which is smaller (the so-called A. 'medusae' - a Northern Kwa-Zulu Natal/Southern Mocambique subspecies). The two larger types differ in that the one has longer recurved leaves (the typical A. barberae look) while the other has broader, more straight leaves.
A. dichotoma has a large natural range in the Northern Cape/Southern Namibia and this range overlaps with various other types of aloe - most notably A. ramosissima. These two species hybridize naturally and I have seen such trees in the wild. I suspect the difference in looks of A. dichotoma from some localities might be ascribed to a small amount of A. ramosissima parentage in the A. dichotoma gene pool. These trees typically have a thick heavily branched crown that starts lower down the trunk.
These subtle differences in nature could account for the variance seen in A. 'Hercules'.