Lithops - Au Cactus Francophone
Lithops - Au Cactus Francophone
Lithops - Au Cactus Francophone
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which he named Mesembryanthemum turbiniforme, as follows; Planta acaulis,<br />
obconica, superne truncate obscuro punctata. The plant was subsequently re<br />
named <strong>Lithops</strong> turbiniformis by N. E. Brown. This discovery was made by<br />
Burchell on September 14th, 1811, at Zand Vlei, in the Prieska district (Fig.<br />
1). More than a hundred years elapsed before this plant was rediscovered by<br />
Pole Evans in more or less the same locality as that in which it was found<br />
by Burchell. The next species to be described was named Mesembryanthemum<br />
pseudotruncatellum by Berger in 1908. This plant was found in Damaraland,<br />
Great Namaqualand, and as we now know, in the vicinity of Windhoek. In<br />
1912 Mr. Leslie discovered near Vereeniging a plant, named by N. E. Brown<br />
Mesembryanthemum Lesliei after its discoverer. These early discoveries show<br />
that the genus has a very wide distribution, as Windhoek and Vereeniging lie<br />
far apart and they are both about 500 miles from Prieska.<br />
During the period 1920–1933, large numbers of species were discovered<br />
both in the Union of South Africa and in South West Africa.<br />
Kurt Dinter, the indefatigable collector, deserves to be mentioned, for<br />
it is largely due to his enterprise that our knowledge of this genus has been<br />
so appreciably increased. It must be borne in mind that he undertook his<br />
collecting tours by oxcart and under very arduous conditions, as the majority<br />
of the South West species occur in the most arid and uninhabited parts of<br />
that dry country. One requires a knowledge of the country to know where to<br />
look for species of <strong>Lithops</strong>, as these plants are perhaps the most difficult of<br />
all to find in the field and a fairly sharp eye and one might almost say intuition<br />
are needed to find them. In the dry condition one walks on these plants without<br />
seeing them.<br />
Each individual plant consists of more or less contiguous leaves on a<br />
short stem. The whole diameter of the plant varies from about 0.5 to 5 cm.,<br />
the latter being an extreme case, as these plants are usually about 1–2 cm.<br />
in diameter. In some plants, the two leaves are separated by a very narrow<br />
fissure and in others the lobes, at least in the old stage, stand firmly apart<br />
from one another (L. divergens, L. Comptonii, L. Helmuti).<br />
4<br />
STEM<br />
As mentioned above, each individual plant consists of two more or<br />
less contiguous leaves on a short stem, the cross section of which is circular.<br />
The length of the internode is about the same as the thickness of the leaf,<br />
and is named the insertion zone. The stem is therefore not free, but only<br />
becomes so after the succulent leaves have shrunk and perished. The remains<br />
of the old leaves are dry and papery, and they protect the young leaves in<br />
their early, stages of development.<br />
In the young stage the plant does not branch at the growing point of<br />
the stem, i.e. at the base of the fissure, but a new pair of leaves is formed