According to the literature, this is a more or less erect shrub up to 9 cm tall.
The leaves are 5-8 mm long and 4 mm wide and thick, tipped with a diadem consisting of 4-9 bristles*.
The white flowers are about 3.8 cm wide and appear in spring and summer: Sept.-Dec.; they produce fruits with 5 or 6 compartments.
The plants occur in the Willowmore district.
* In some of the plants shown here, the diadems have many more bristles. Because all other characteristics agree, I take it all pictures represent the same species.
There are only three species of Tanquana; the other two being T. hilmarii and T. archeri (which I have never seen). All three used to be called Pleiospilos because of the dotted leaves, but actually the two genera are not closely related.
Over time T. prismatica may form clusters of up to 30 branches. The leaves are unequal, egg-shaped in young plants but more oblong later, with a length of 2.5-4 cm.
The strongly scented flowers are to 4 cm in diameter and appear from February to May.
The plants are not uncommon on stony flats in the Ceres-Laingsburg area, where they receive 100-150 mm rain per year, mainly in winter.
Below are some pictures to give you an idea of the conditions in the plants’ habitat.
Plants of this subspecies are usually rather short-lived; they occur from southwestern Namibia southwards to Laingsburg and south-eastwards to Queenstown .
The branches are usually lying on the ground and rooting at the nodes.
The leaves are 3-5 mm long and 2-3 mm wide.
In December to April the plants are decorated with cream flowers.
This is one of the very few southern African Aloes without spines on the edge of the leaves.
The stems are rarely over 30 cm long and the leaves are up to 60 cm long and 15 cm wide, from greenish-grey to pinkish-grey with not very distinct longitudinal stripes.
The flowers are bright orange or (rarely) yellow on inflorescences up to a meter tall and appear from winter to early spring (August-October).
On flats with deep loamy soils, the plants are often abundant, but they also occur on rocky slopes.
The plants are not grazed, so when you see a great many together, this is an indication of heavy overgrazing of the area in the past. They are widespread from Worcester in the Western Cape to Queenstown in the Eastern Cape.
Eburneus means ivory-white and refers to the colour of the flowers. These appear from June through September and are up to about 3 cm in diameter, rather big for the size of the plants.
The leaves are densely covered with papillae and 1-2 cm long.
The species has a relatively small distribution area in the southwest corner of the Great Karoo, from Sutherland to Matjiesfontein.
Like other Stomatiums, these plants form small to medium-sized cushions, which over time often die down from the centre.
The leaves are spatula-shaped to three-angled in cross-section and distinctly broadened towards the tips. The margins usually bear 3-6 (but sometimes up to 18) teeth, whereas the keel is either smooth or decorated with 1-3 teeth.
The flowers appear in September; they open in the evening, are to 22 mm in diameter and have bright yellow petals with red tips.
The plants are found in the southwest corner of the distribution area of Stomatium, on shallow gravel and stony ground in the Sutherland-Laingsburg area, where it can be quite cold in winter.
The pictures were taken in spring and summer, between mid October (#1) and mid January (#4).