Based on genetic research, in 2013 Ronell Klopper and Gideon Smith created the genus Aloidendron to accommodate 6 species of tree aloes, including Aloe dichotoma.
The plants form trees with a rounded crown, with stems to 1 m in diameter at the base and usually 3-4 m tall (sometimes up to 9 m).
The bark on the trunk peels lengthwise, forming large scales with hard and razor-sharp edges. The leaves are about 30 cm long and 5 cm wide at their base.
In winter (May-August), the flowers appear; they are pollinated by starlings, sunbirds, weaver birds and white-eyes.
From the Brandberg Massif in Namibia to Upington, Kenhardt and the Nieuwoudtville area in South Africa, the species forms a conspicuous component 0f the landscape. The plants occur in open sites, usually in rocky terrain but also in flats.
Depending on the area, rainfall (between 50 and 300 mm per year) may occur in either summer or winter.
When one sees a great many of these plants together, this usually means that the local vegetation has been heavily disturbed (the plants are rarely eaten by stock or game because the juice in the leaves is very salty). They can absorb a great amount of water after rain, not only in the leaves but also in the roots.
The plants usually live for only a few years or, in more official terms, they are annuals or short-lived perennials, up to 50 cm tall with leaves 3-4 cm long and about 1 cm thick.
The flowers appear in spring (August-October) and produce large fruits with woolly seeds.
This species (the only one in the genus) is widespread on dry sandy or loamy flats from southern Namibia and Bushmanland to the Little Karoo.
Compared to ssp. corallina, these plants look more sturdy, with leaves 4-5 mm long and wide. The leaves are also much whiter.
Another difference is that they have a tuberous main root up to 1.2 cm wide (macrorrhiza= with a big root).
This subspecies has a generally more northern distribution, from the Grunau-Warmbad area in Namibia to adjacent parts in South Africa, from Vioolsdrift to Kenhardt, usually on coarse sandy flats.
The flowers appear from October to January.
As the first picture shows, these up to 2m tall, dense clumps are very conspicuous in the field.
The branches are yellowish-green to grey-green, usually up to 3 cm thick at the base and 1.2 cm in diameter above, with leaves that soon disappear.
Between July to September one can find the plants in flower.
The plants occur mainly in flat open gravelly or sandy plains, sometimes on low stony slopes. They are widely distributed from the Haalenberg east of Luederitz in Namibia to Kamieskroon in Namaqualand and Namies in Bushmanland.
And here some pictures of subsp. prolifera.
More pictures of subsp. columnaris.
It takes plants of this species 5-10 years to reach maturity and become columnar.
There are 2 subspecies, each with a number of local forms.
The plants are often locally abundant on gentle slopes and in depressions (often with quartz gravel); sometimes they also occur in shallow soil on rocky outcrops.
The flowers are white, pale yellow (often tinged red) or rarely almost red.
Subsp. columnaris is usually unbranched, with columns 2-3.5 cm wide, often as long as broad.
The inflorescence is swollen, rounded to flat and appears from May to September
The plants are monocarpic, which is another way of saying they die after flowering.
They are found in most parts of the little Karoo, the adjoining western Great Karoo and towards Calvinia.
Subsp. prolifera reaches a height of 3-10 cm when in flower and forms several short branches at the base. Often these branches easily break off and take root.
The inflorescence is more or less branched and appears from July to October. After flowering, the plants often regenerate from the lower branches.
This subspecies occurs in most parts of Namaqualand and adjoining areas of Bushmanland and southwestern Namibia.
The four pictures all show ssp. columnaris.