VISIT TO THE LITHOPS PSEUDOTRUNCATELLA SUBSP. PSEUDOTRUNCATELLA VAR. ELISABETHIAE COLONY

On 3rd May 2019 the members of the Lithops Research & Conservation Foundation visited the Lithops pseudotruncatella subsp. pseudotruncatella var. elisabethiae colony with the aim of assessing the size and health of the population in this unique habitat.

This colony was first discovered on the farm presumably in the early 1930’s and plants were first collected in 1932 by Mrs Elisabeth Schneider. The plants were described as a new taxon in 1933 by Professor Dinter after he visited the colony and named it for Elisabeth. Dr de Boer & Boom later corrected the classification of this taxon to be a variety of Lithops pseudotruncatella. Wilhelm Triebner, a plant dealer and nursery man reported he had found 800-1000 plants in the colony in the mid 1950’s. This is probably a gross over-estimation of the colony size as he over-estimated most Lithops colonies that he visited in order to justify the large numbers of plants that he collected to sell in his nursery. The visit to the colony in 2009 by Tok Schoeman, Denise Schoeman, Ronald Uijs, Frikkie Mouton and Hilde Mouton (the latter three being members of the Foundation) discovered about 45 plants which is near identical to the 2019 count and probably a true account of the size of the population.

During the 2019 visit a total of 50 plants were found in the potential habitat of 318.9 m2 giving a plant density of 1 plant for every 6.4 m2 (inverse: 0.16 plants /m2). In all, 68 % of the plants were adults with a very high number of young plants (17/50, 32 %) of two distinct age groups in the population. Most of the adult plants were double headed (18/50, 36 %) or single headed (12/50, 24%) with one three headed plant and one dead double headed plant also found. In all, 17 of the adult plants had flowered, were flowering and/or had developing flower buds. Successful germination of the seeds and growth of the seedlings for the first six months is dependant on the micro-habitat around the seedling being constantly humid during this period. Such conditions only occur every few years of high rainfall and adequate follow-up rain and only 2 – 5 % of the seeds that germinate will survive to become adult plants.

The habitat consists of a 1-2 cm layer of soil, mostly stabilised by tufts of grass, on the exposed and sloping gneiss rock. This habitat is highly fragile and prone to erosion-damage by run-off water during rain. An estimated 30 % of the habitat has no soil covering on the gneiss rock and is considered unsuitable for the plants at present. Since Lithops plants have no active mechanism of distributing their seeds, the seeds in this habitat will be moved down the slope passively by the running water to possibly germinate lower down the slope. Over time the population will thus also move down the slope and will eventually be lost. It is recommended that the colony should be managed by sowing seeds higher up on the slope with the aim of establishing a population of the plants on the slope above the present colony. These plants higher up on the slope will hopefully then produce seeds which will wash down the slope and keep the colony viable in the future. The slight slope of the habitat to the north is also devoid of plants and this seemingly suitable habitat can also be considered for the re-introduction of the plants via seeds. The Foundation can also provide adult plants that can be re-introduced into the area higher up and on the northern slope. Similar re-introduction programs by the Foundation with other Lithops species where colonies have been wiped out, have been ongoing for several years in southern Namibia.

The Lithops Research & Conservation Foundation is grateful to the owners of the farm for their warm welcome and enthusiasm. We feel privileged to have visit the var. elisabethiae colony and would be eager to help with any management of the colony that might be needed to safeguard the continued existence of these plants.

Members of the LR&CF with the owner of the farm examining the Lithops pseudotruncatella p. elisabethiae habitat.

A pinkish Lithops pseudotruncatella p. elisabethiae double headed plant with the remains of old flowers next to a young plant of about 3 years old.

A double headed adult Lithops pseudotruncatella p. elisabethiae plant with exposed sides where the soil substrate has been eroded away by recent rain.

A young Lithops pseudotruncatella p. elisabethiae plant nestled among the quartzite grid in the natural habitat.

A buffish-yellow coloured Lithops pseudotruncatella p. elisabethiae plant with an unequally sized smaller head and a gap in the fissure where the green seed capsule had been eaten away probably by an herbivorous insect.

A perfect single headed Lithops pseudotruncatella p. elisabethiae plant with a protruding flower bud and showing the typical unequal sized heads of this taxon.