THE RETURN OF LITHOPS WERNERI

by Keith Green (photographs also by the author unless otherwise stated).

 

 

 

On a field trip with Professor Desmond Cole and his wife Naureen in 2007 I was taken to the type (and only known) locality of Lithops N.E.Br. werneri Schwant. & Jacobs. in the Erongo Mountains of Namibia, where our searches failed to locate any specimens. The story goes that around 2003/2004 there had been a great storm and “wash away” of the substrate where the plants had grown, resulting in the population being totally eradicated. The Coles were of course well aware of this story before our visit, but like me wanted to see for themselves. Together with my wife Debra, I searched the locality again in 2009 and once again failed to find L. werneri. Several searches by others, including the Namibian Lithops expert Tok Schoeman of Windhoek, likewise turned up negative. Whether our collective failures were entirely down to natural causes remains a matter of conjecture, but I think unlikely. As L. werneri clearly evolved and grew at this spot for very many years and that historically we know large numbers were removed by unscrupulous collectors, it seems much more likely the fundamental cause was human.

In this instance however, Tok and I felt humans could do something to help re-dress the balance. Thanks to the research based collections of the Coles, their C188 collection number from this very location has became well established in cultivation and presented us with an opportunity. Tok discussed the issue further with Sonja Loots, who is the curator / red list officer of the National Botanical Research Institute of Namibia, and she agreed that a habitat re-introduction of L. werneri to the original locality was not only possible, but could also be monitored by her institution. The land owner was in favour and we had further support from fellow Namibian born but U.K. based Lithops grower Roy Earle. I raised the issue with the British Cactus and Succulent Society Conservation Fund and they kindly donated money to help cover our necessary 4X4 car hire costs. My son Christopher accompanied me, Tok’s wife Denise accompanied him and Sonja’s mother Lida accompanied her in a separate government vehicle. Together with Roy Earle our party consisted of seven, and the attempt to re-establish L. werneri at its only known wild locality went ahead in February 2012.

Fig. 1. A young specimen in Tok’s collection awaiting transplantation

After discussing the situation in depth, we decided to focus on the transplantation of young plants directly back into suitable substrate at the locality. Tok was absolutely crucial to this project, for it was he who supplied the plants, produced from four, first or second generation C188 specimens he purchased from Etwin Aslander in Cape Town. The flowers were hand-pollinated under controlled conditions and the resultant seed grown by Tok at his home in Windhoek (Fig. 1). All of the one hundred and fifty or so plants were typical L. werneri so we had no doubts concerning their purity.

Fig. 2. Erongo rocks (see p. 315 of Flowering Stones 2005).

On day one we met up at Tok’s home in Windhoek, collected the L. werneri plants and set off to the locality. As Sonja was the official government representative, she had custody of the plants en route. Most of that drive was on a tarred road and the minimal amount of traffic made it easy going. We left the tar after Usakos and continued on gravel to the farm that contains the L. werneri locality. Then after meeting with the farm owner and to the bemusement of some distant giraffes, we proceeded off road to the locality (Fig. 2).

As previously I had searched here with the Coles, it was my responsibility to direct the group to the tiny spot close to the spectacular rocks where L. werneri was once found. I got my bearings and we commenced a thorough search, none of us expecting to find any plants. After a couple of hours we were all about to stop and we gathered together to discuss appropriate sites to stage the re-introduction. Just then Sonja made a noise, something like “Oh Oh”, for she had found a specimen of L. werneri! We were elated and searched intently around that immediate area where we found just a few more mature plants. These were growing within a meter of each other and importantly sported seed capsules. Amazingly L. werneri was not extinct in habitat, although due to the low plant number and restricted growing area Sonja was clear the re-introduction should

Fig. 3. A mature L. werneri with closed seed capsules.

Fig. 4. The same L. werneri as Fig. 3 with open seed capsules.

continue. We took photographs (Fig. 3 is one such) and spent the night on the farm discussing the find. Given the size of the specimens found, it was felt that these may well have survived a mass excavation as seed. As with my previous two visits to this locality we could find no evidence to support the “wash-away” theory.

Fig. 5. Gently transplanting L. werneri back into habitat (photo: Christopher Green).

There had been no rain on this farm for around a year, but we awoke the next morning to a gentle rain shower which nicely and uniformly soaked the whole locality prior to our return. This was day two and we arrived to find the tightly closed seed capsules of day one now fully open and almost empty of seed (Fig. 4). Having found habitat specimens, we could observe their growing preference and we discovered the soil beneath the pebbles where they grew was only around a half to one centimetre in depth. We searched around the area and identified seven similar sites, one of which supported some Avonia species that often grow alongside Lithops in the veld. Our young plants were planted in groups of ten to twenty five by making small “dibs” into the nicely damp substrate and being gently dropped in. The soil was then firmed around the roots and plant body, before further soil was placed on top and watered to settle the plants in (Figs. 5 & 6). They were then surrounded with habitat stone (Fig. 6) and exact GPS co-ordinates taken and recorded for future monitoring. I think we did a reasonably good job because after planting I found it very difficult to see the plants we had just put in (Figs. 7 & 8). It was hot and surprisingly hard work transplanting the specimens, but intensely satisfying. The land owner seemed as pleased as our group with the work and will help with future conservation efforts. To top it all it rained again that evening and overnight, so we could not have had a better weather sequence. We left the following day with plans for Sonja to return in a couple of months to monitor progress.

Fig. 6. Tok Schoeman (with cigarette) and the author at work (photo: Christopher Green).

Fig. 7. A nicely transplanted L. werneri.

Fig. 8. At least 9 transplanted L. werneri in view (photo: Christopher Green).

Although I feel positive about the future of this locality, we must remember the entire colony consists of a small number in a population that is critically endangered (Figs. 9 & 10 show more habitat specimens). Accordingly the National Botanical Research Institute of Namibia expect our party to keep the number of plants and their exact location as confidential information.

Christopher and I flew home a few days later via Johannesburg where we had lunch with Naureen and Desmond Cole and were able to fill them in on the trip. All that remains is to “hold thumbs” (as they say in Southern Africa), hope our transplanted specimens adapt and that seed from the few mature specimens germinate well. I will be keeping in touch with my Namibian friends over the coming months and will relay news of the locality back to the B.C.S.S. in due course. I send sincere thanks to Tok, Denise, Sonja, Lida, Roy and Christopher for their company and help, and also to the B.C.S.S. Conservation Fund for the financial assistance they gave us with hiring the 4X4.

Fig. 9. An undercover L. werneri as found in habitat.

Fig. 10. L. werneri, typically situated.

Fig. A. Roy Earle (left) and the author near the L. werneri locality (Photo: Christopher Green).

On the Return of Lithops werneri

One year on from the conservation based field trip of February 2012 (as reported in CACTUS WORLD vol. 30, (2) pp. 99-102 June 2012), two of our group revisited the locality. Tok Schoeman and Roy Earle inspected the seven transplantation sites together with the original “mother” population, and on balance I was pleased with their report.

Although we would not have attempted a habitat reintroduction without a reasonable chance of success, no more than a 25% survival rate among the seedlings handed back to nature seemed a realistic expectation. Most losses were expected during the first weeks following transplantation, with plants surviving that first year having a good chance of holding their own and setting seed during subsequent favourable seasons.

Whilst indeed there had been a sobering amount of seedling losses, others had become established and in some instances looked ready to flower. One particular group of 20 seedlings had done particularly well, with 17 of their number being observed. This group had been planted around 100 meters from the “mother” population and close to a habitat Avonia (photograph below © Tok Schoeman). As Avonia and Lithops are often seen together in habitat, this was with hindsight, a good indication of that particular microclimate. There had been a little rain during the year, and the “mother” plants looked healthy.

Some simple mathematics reveals that after this first year there has (as uncannily guessed) been at least a 25% instance of establishment among our transplanted seedlings. The long term survival of this most rare and charming little species at its only known wild locality therefore has been increased. Thanks are again extended to the help provided by the B.C.S.S. members and the conservation fund.

References

Cole, D.T. & Cole, N.A. (2005) Lithops Flowering Stones. Milano: Cactus & Co.