The Cactus Patch
Volume 8       June 2005      Number 6

A New Crassula
A Letter From Bruce
by Bruce Hargreaves

Having rested from the Maitisong Festival on Sunday, we celebrated my birthday on Monday and I gave a talk on names of birds at the Bird Club on Tuesday, 19th April. (Did you know, for instance, that the American "robin" is in the genus Turdus which is Latin for Thrush and that it is really a thrush?)

On the 20th ten of us set off on the ninth Millennium Seed Bank Trip. After a night at Mahalape (which is not far N of Gaborone) we drove west to Shoshong, climbed a hill and relocated the Transvaal Red Baloon, a rare shrub with inflated fruit. We also found some next to the Kgotla (traditional Center) of Shoshong which did not require climbing! This is good because the kgotla area is a proposed historic monument and a rare plant adds to its value.

Next morning we stopped just west of Shoshong and found lots of Stapelia gettlifeii in full bloom. Turning north we found Huernia zebrina with large flowers and then stopped about haslfway to Serowe at a promising site and found, among several other interesting plants, a new species of Crassula. It may be Crassula fragilis, which is known from several southern African countries, but it is, at least, new to Botswana. It was in bloom and fruit and we collected it for the seed bank. The beautiful Plectranthus cylindicus was blooming nearby, but this is well known.

We spent the night at Serowe where we had unseasonable rain which soaked a couple of tents (the fly sheet blew off mine). Next day we proceeded north to look for Jatropha botswanica, one of the few endemics here (endemics are found nowhere else), but failed to find it as there is a new road and the old road no longer goes through. On the way back we stopped at an unusual sandstone outcrop where a daisy-bush was blooming. It looks like the Euryops I know from Lesotho (where sandstone outcrops are more common) and may be Euryops subcarnosa of which Pretoria has a specimen from Botswana. Nearby there was a large colony of a mesembryanthemum which might be Phyllobolus splendens, another species which Pretoria has which was collected in Botswana. It was in fruit, which we collected.

On Saturday, 23rd April, we drove east to Sefophe where I relocated Ceropegia crassifolia which I had recorded there in 1990 as a species new to Botswana. It was in flower and young fruit. We spent the night at Bobonong and next morning stopped at a site just north of town with Hoodia currori, Euphorbia limpopoana and Taveresia barkleyi. There was a large Orbea species, but it was not in flower, so I will have to grow it to identify it. (I have several such plants, all reluctant to bloom!) At Semolale to the west we found Jatropha schlecteri with flowers and young fruit. The hill there had lovely agates and was topped by old stone walls. Further west we reached the Shashe River which there forms the boundary with Zimbabwe. There we found Jatropha spicata, the only shrubby species in the genus in Botswana. We returned to Bobonong for the night.

On Sunday we drove west and north to Francistown and relocated the endemic Jatropha botswanica in flower and one young fruit. Next morning we drove north and a bit west to Themashanga and located Anacampseros rhodesica, Rhaphionacme grandflora, Euphorbia espinosa, Euprorbia venteri, Plectranthus tetensis, Eulophia hereoensis, three species of Ceropegia (none in bloom), Adenia repanda (highly poisonous but being eaten by caterpillars) etc. A rich area for succulents!

Monday the 24th we drove northwest and north to Tutume were we found the healthiest population of Euphorbia venteri yet seen as well as Aloe litoralis. Further west we found a ceropegia with old fruits, possibly Ceropegia nilotica, as well as Botswana's only epiphytic orchid, Anselia africana.(An epiphyte grows on a tree.) Finally, on Tuesday we drove north to Tshesebe, the type locality for Euphorbia venteri. (A type locality is the place from which a plant was first described.) We found the plant as well as other succulents and a non-succulent lily Gloriosa superba which had an unusual brown and yellow flower. On the way back we stopped and collected fruits from a tree of Eleaodendron matabelensis which had much of its bark stripped. It seems this tree is used as a love potion! Closer to Francistown we found Ceropegia crassifolia again. That night we celebrated the birthday of Iain Darbyshire who was with us from Kew Gardens in England.

We hated to leave Francistown where we had electricity (and some of us even beds) as well as hot water, but on the 30th we drove south to Serule and then west on dirt roads to the Khama Rhino Sanctuary. Just west of Serule we found Orbea maculata in full bloom. That night it turned bitter cold- the first of winter this year. The 1st of May was a holiday, but we went out collecting amidst the zebra, giraffe etc. Fortunately all we saw of the rhinos were footprints. We found a ceropegia which is probably Ceropegia lugardae, but it had no flowers. That night we celebrated with what was termed the "Last Supper". The night was no warmer, but we had a bonfire.

On our way back home we stopped north of Lephephe and found a new site for Jatropha botswanica. We all agreed #9 was the best seed bank trip yet.

To finish off the histories I bought in Pretoria, I turn to The Zambesi Journal of James Steward. Although it was written from 1862 to 1863, it was not published until 1952 (Chatto & Windus, London). He was a companion of David Livingstone on some of his exploits. He describes the widespread use of cannabis (marijuana) in the Zambezi area as well the violet tree Securidaca longipedunculata (although at that time the latter was not known to be a hallucinogen.) The violet tree (named as buaze or string) is listed for oil and fiber. He also describes a baobab at 97 feet in circumference. (Not the world record, but a big tree none-the-less). Also described are a euphorbia hedge, a triangular "cactus", euphorbia trees and candelabra "cactus" [not very consistent]. Also mentioned are aloes and an arrow poison that might be Strophanthus kombe. This is a very interesting journal for me as it is an early record for many of the plant uses I have recorded since.

Euryops subcarnosa

A new Crassula

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