TREE LIFE 528
AUGUST 2024
FUTURE EVENTS
PLANNED EVENTS:- AUGUST
Since inclement weather or other issues may vary our plans, WhatsApp Tony Alegria on 0772 438 697 to join our WhatsApp group for last minute updates.
Saturday 3rd August 2024:- visit to the National Botanical Gardens
Meet at 8.30 in the main car park and join us for an interesting morning looking at trees that catch our interest.
Sunday 18th August 2024:- visit to Ewanrigg Botanical Garden
We begin botanising at 09:30 am and will have an early lunch so as well as water bring your chairs and a picnic lunch. I have asked for special rates for us and also invited any National Parks staff to join us for the tree walk. We can meet at CABS and share transport – there is a toll gate before we get onto the Shamva road. Please watch your WhatsApp for further details.
REPORTS FROM PREVIOUS OUTINGS
NATIONAL BOTANICAL GARDEN OUTING SATURDAY 6th JULY 2024
By Tony Alegria, photos by Jim Dryburgh, Mark Hyde and Rob Burrett
Comparison and confusion
On a cool, sunny, calm Saturday morning the ladies: Anne Sinclair, Dawn Siemers, Linda Hyde, Sonya Messick and Soo Fawcett along with the guys: Busi Malunga, Charles Crawshaw, Jim Dryburgh, Mark Hyde and I enjoyed a morning’s tree outing. Sonya joined the Society last month and came back for her second morning’s walk. Soo Fawcett hails from the Mutare area and has now relocated to Harare so we are hoping to see her often.
With so much doubt concerning one atypical fig tree we decided to compare it with a different fig tree which looked similar, but we know that trees, just like the human race, are highly variable.
Samples were taken from both trees and compared in detail. The guru was unable to identify the fig tree – just shows how difficult it can be!
We looked at an Albizia which was coming into bud and decided it had to be Albizia anthelmintica. Worm-cure albizia, as they flower very early compared to the other albizias.
Acacia eriocarpa
Acacia eriocarpa – stipules
In the same area was a bushy-looking acacia which had previously been mis-identified as Acacia amythethophylla because of its big leaves. We know now that it has stipules when it has young leaves so it turns out to be an Acacia eriocarpa. Stipules are rare for acacias! Another case of variability and mis-identification.
Acacia senegal var. leiorachis
Then there was a tree trunk that looked like an Albizia tanganyicensis but was too “twiggy” to be so. No leaves whatsoever so we had to wait for Mark to return from seeing if the Ceiba pentandra was in flower. He identified the tree as an Acacia senegal var. leiorachis. Slender three-hook acacia at which time we looked and found the tiny hooked thorns – 2 pointing up and 1 pointing down.
We looked at a large, wide-spreading Albizia zimmermannii which was full of pods and had symmetrical leaflets. Close by was a small albizia which one would assume was an offspring – wrong! This was an Albizia schimperiana with asymmetrical leaflets with some of them having a second well-defined vein.
Some of the other trees we looked at that were not mentioned above: Acacia gerrardii; Combretum imberbe; Combretum zeyheri, Balanites aegyptiaca and Tamarindus indica.
VISIT TO ST. MICHAEL’S PRESENTATION PRIMARY SCHOOL:
SUNDAY 18TH AUGUST 2024
The report on this outing will be included with next month’s Tree Life.
OTHER NEWS AND SHORT NOTES
LOST AND FOUND: WILD CAMPHOR IN THE MUKUVISI WOODLAND
By Mark Hyde, photos by Mark Hyde
Tarchonanthus
leaves and flower buds
This article discusses the recent rediscovery of Wild camphor in the Mukuvisi Woodlands.
But firstly some details of the species itself. Wild camphor, Tarchonanthus camphoratus, is an indigenous shrub or small tree which can attain 8 m in height. It is in the Asteraceae, the sunflower family, and is one of the relatively small number of woody species in that family.
It is often multi-trunked and sprawling and has bark with distinct longitudinal ridges. The leaves are alternately arranged and are discolorous, green above and white beneath. The margins are entire. Crushing a leaf produces a smell of camphor, hence the common name.
Tarchonanthus – multi-trunked base
Trees are either male or female. Female trees produce seeds which when mature are covered in long woolly hairs.
The species is rare in the Harare area; apart from the Mukuvisi and Cranborne records to be discussed below, the only other record I have anywhere near Harare is from Harava Dam in 2016.
It should not be confused with the completely unrelated Camphor tree, Cinnamomum camphora which is commonly cultivated in Harare and is native to Asia. It might also be confused with Brachylaena discolor var. rotundata but the leaf margin of that usually has spiny teeth.
Wild camphor in the Mukuvisi
The presence of the Tarchonanthus in the Mukuvisi has been known for a long time. The first explicit record is a mention by Kim Damstra in Tree Life 80. Writing in October 1986 he notes that
“Meg has recently discovered some specimens in the Mukuvisi Woodlands”.
Note the plural word specimens and Meg told me years later that there were originally two plants.
Kim Damstra also reported the presence of Tarchonanthus on 14 December 1986 in Tree Life 83 and I was shown a plant by Meg Coates Palgrave on a Tree Society outing in 1987.
Twenty years later, on 19 Aug 2007, Meg and I searched for and re-found this plant. I estimated a position and in recent years have regularly thought of trying to re-find it but never got around to it.
Tarchonanthus
With Tony in front
On 12 November 2023, I was botanising with Werner Fibeck, looking for orchids, and my eye was caught by an odd-looking tangled large shrub on an anthill. This was a Tarchonanthus!
I mentioned this find to Tony Alegria and because of Meg’s comment that there were two trees, he and I decided on 9 April 2024 to search again. Almost immediately we found another specimen and later in the same morning a third one. This third one was at the coordinates of the 1987/2007 one.
All three plants occur on termite mounds and anticipating further finds, Tony, Jan and I mounted a search of termite mounds on 30 April 2024. On this occasion we drew a blank, but we did compile a useful list of woody species occurring on termite mounds which is the subject of the following article by Jan.
Tarchonanthus
Point locations in the Mukuvisi Woodlands
The three trees are in a similar area of the Woodlands as may be seen from this map.
One further thing is that I searched the National Herbarium for specimens of Tarchonanthus and there are two specimens collected in 1948 by Professor Hiram Wild from termite mounds in Cranborne, which is just to the south of the Woodlands.
Full details, including precise locations, of all the records mentioned in this article can be found online at
https://www.zimbabweflora.co.zw/speciesdata/species-display.php?species_id=159080.
TREES ON ANTHILLS
By Jan van Bel; Photographs by Mark Hyde
We are all somewhat familiar with anthills or termite mounds. These small hills from 1 to 4 m high, are sometimes covered with a few shrubs or trees. These days you are lucky if you can find an anthill in a public or easily accessible place. Anthills are being scraped off by brick moulders who use the soil which is rich in clay and minerals. Farmers also like to use it as a substitute for fertilisers. Ants and termites, often found together, bring up minerals and organic material from metres down. We can imagine that some plants and trees will be stimulated and easily find a foothold here.
One of the anthills in the Mukuvisi Woodlands
In the Mukuvisi Woodlands, a protected nature reserve, we still find quite a few anthills. The idea of making a list of tree species on anthills came to Mark Hyde, while we were searching the anthills for one specific species: Tarchonanthus camphoratus, an indigenous tree, rare in Harare, more common further south.
The existence of this species was known from the past always on anthills and that is why Mark, Tony and I were spending a morning inspecting anthills in the Mukuvisi. It was also an occasion to learn some more from Mark and Tony.
Full details of the history of Tarchonanthus in the Mukuvisi are described in the companion article by Mark, Lost and Found.
After having examined about 10 of these hills in the Mukuvisi Woodlands we observed a pattern of the vegetation. Some of the hills had large old trees on them. I remember Pappea capensis; Schotia brachypetala; Albizia amara, we saw 2 of them together. One old tree on top of a hill could have been a Maerua triphylla, a tree frequently seen on termite mounds (per Meg). We had seen a smaller one on another hill, but this one was too high up to confirm. Ficus burkei, Combretum molle, Lannea discolor were other big ones. What was overwhelmingly present was Ehretia obtusifolia, more a shrub than a tree and known to like anthills. An attractive shrub when in blue or white flowers, but they had long gone over.
Euclea crispa and especially E. divinorum were repeatedly seen. Grewia flavescens as expected was seen on several hills. Mark also recorded a Grewia stolzii. I remember seeing Flueggea virosa, Solanum species, Gymnosporia buxifolia, Flacourtia indica, Diospyros lycioides, Dichrostachys cinerea. Searsia longipes and Searsia lancea.
As I had not been taking notes and this project of making a list of trees on anthills only came up later, I was lucky to get a copy of Mark’s list of trees from the Mukuvisi Woodlands. Here are some more trees from that list which I had left out or never observed. Allophylus africanus, Dombeya rotundifolia, Euclea natalensis, Mystroxylon aethiopicum, Psychotria kirkii, Rotheca wildii, Rhoicissus tridentata, Scolopia zeyheri, Vangueria randii and Ziziphus mucronata.
We never found another Tarchonanthus on the anthills, but Mark had by now an impressive list of plants, shrubs and trees on anthills. With data from all the years he has been recording, we may hope to get an essay on trees on anthills from his hand sooner or later, or maybe Tony will write a more worked out and scientific treatise about them.
A visit to Siabuwa and Chizarira
Text and photos by Ian Riddell
At the beginning of November 2019, I was part of a BirdLife Zimbabwe team that conducted a survey of the Siabuwa Communal Lands at the base of the Sijarira Horst, the escarpment that forms the northern boundary of Chizarira National Park.
1st November 2019: We set out from Harare via Kwekwe, where we had sourced a drum of fuel, and headed north through Gokwe. The deforestation of the area south of Gokwe was noticeable and depressing but it was good to reconnect with the lovely view over the Sesame valley as we dropped down from Gokwe.
A view along the cliffs of the Chizarira escarpment with Mt. Tundazi in the background
Unsurprisingly we had to go slower and slower as we headed north and the unmaintained tar road steadily deteriorated until, at last, Tundazi reared up to the west, beckoning us on to the end of the journey.
We had arranged to stay at Chizarira Lodge, now defunct and a saddening sight indeed. We set up under the tattered and collapsing thatch of the dining area while the Freckled Nightjars pow-wowed and African Barred Owlets purred a welcome as the night gathered around us.
The next morning we set out on transects. I started from the lodge area, down the steep and rugged slope into the valley below. This area is sandstone, very dry at this time of the year and largely leafless. However, I recorded some of the plants along the way but have to rely here on what I uploaded to iNaturalist, so just a few are mentioned. Euphorbia griseola was growing at our starting point near the ‘bat cave’, which I was keen to revisit. This is the most fascinating of places where the stream from the south suddenly disappears into the deep and sinuous cleft it has carved over the millennia. A few Phoenix reclinata grow here in a hollow but to explore the ‘cave’ you need a long rope and torch, though you can do some chimney-walking down the walls of the crack into the depths (rope still recommended). Large numbers of bats used to live here but I don’t know how they are doing nowadays.
A gnarly Mountain Acacia
After a short transect we walked half a km down the ridge to the edge of the cliff that drops precipitously into the hidden valley that hides the ‘mouth’ of the ‘bat cave’ at its head, but couldn’t see much as the quickly steepening slippery sandstone prohibited close approach. Along this stretch I photographed a twisted Mountain Acacia Brachystegia glaucescens, the dominant tree of the area, and found a group of small trees with gnaw marks that might have been made by porcupines. There were no leaves on them so I don’t know what species they were.
Gnawed but unidentified small trees
We managed a steep climb down off the left edge of the spur into the valley from which you can enter the hidden valley, if you know where to look. It is secreted above a jumble of big boulders and thick riverine trees.
Ian-dianna Jones
Decades ago I did an ‘Indiana Jones’ type thing and sought out the narrow hidden valley, ferreting through and over the boulders and trees. There was a painful entry fee demanded by the belligerent Polistes paper wasp guardians but that is only right and expected for any mystical place.
Once inside you are hemmed in by high sandstone walls bordered on both sides by thick bush and some trees (I can’t really remember what those were after all these years), with a sandy rivulet running through the middle. The sandy and sometimes watery path is perhaps the easiest to follow until you reach the head of the valley, where you are confronted by the narrow, twisting doorway where the walls come almost together. The darkness beyond entices you to enter but, this being my first time, I was ill-equipped and didn’t know a torch was required. The gloom looked inviting, as long as you are prepared for quicksand and an enormous python – ohh, to have the chance to go back again!
Camponotus ants on Tiliacora funifera fruit
On this visit, we certainly weren’t prepared for an adventure and the suggestion would have horrified my teammate, who had already been put to the test climbing down the spur.
I didn’t check if the ancestors of the guardians were still there! But amongst the boulders and trees climbed a large Elbow-leaf Tiliacora funifera, the bunches of fruit with many elegant Camponotus sugar ants delving into every gap in search of sap, perhaps?
Fed by the little marsh and spring in this spot the Rain trees, Philenoptera violacea, were in full leaf and laden with sprays of mauve flowers. We navigated the marsh by hopping from high spot to high spot. Amazing-looking stalk-eyed flies were caught by my camera lens as they posed on sedge leaves, and as we moved downstream on a new transect we came across a pair of delightful Mountain Wagtails in the short grass amongst Phragmites that was much munched by cattle from nearby kraals.
The “Baboon Altar”
Climbing out of the dense greenery of the riverbed we found a steep trail back up onto the dry sandstone. A lot of lithophytic Selaginella imbricata fern grows in the area.
From the Baboon altar, we had a view back to the old lodge, the derelict units lining the cliff edge.
No baboons were around on this hot morning but a little further on, at the base of a tree, was a nice find – flowering Large-fruited Olax, Olax obtusifolia.
Pictures can be seen on the website https://www.zimbabweflora.co.zw/speciesdata/species.php?species_id=121570
Back on the river and further upstream, as we navigated the deep sandstone gullies, I photographed a budding/flowering Purple Hook-berry Artabotrys brachypetalus, complete with the typical galls one finds on this species. Mountain acacia was dominant on the slopes and ridges and large patches of Selaginella imbricata provided greenery where soil gathered on the rock. Large-leaved Rock figs, Ficus abutilifolia and Ficus sansibarica subsp. sansibarica provided the greenery in the gullies of this predominantly grey landscape.
By 1 p.m. we had reached the access road to the park. My confrère was really struggling with heat exhaustion so I spent the afternoon wandering about the bush and revisiting old haunts in the area.
2nd November
The Ent Fig (Ficus sansibarica) – 1996 (left) and 2019 (right)
We started surveys close to the base of the escarpment, hoping to get some cliff-dwelling raptors, so were dropped off at the ‘Ent Fig’ (Ficus sansibarica). With non-consumptive use of the area having ended with the demise of the lodge, the council had granted a hunting lease and it was appalling to see a new track passing between the legs of the fig – such disrespect, not to mention that vehicular traffic will damage this wonderful tree.
We inspected the nearby spring, with African Ebonies Diospyros mespiliformis and other tall trees shading the area, and headed up into a valley with drier thicket and thick bush. Following elephant trails over a spur thrusting down from the escarpment, we descended the slopes overlooking the road climbing up the Access Gorge into the park. We visited two more springs here with various Diospyros species, Baobabs Adansonia digitata, Sausage trees Kigelia africana, Ficus species and others.
Towards the road I photographed a Wild Citrus, Citropsis daweana, and we passed through drier clumps of Combretum, Sickle bush Dichrostachys cinerea, Buffalo thorn Ziziphus mucronata, Friesodielsia obovata, Grewia spp., Cleistochlamys kirkii, Excoecaria bussei, Strychnos potatorum and many other species on our walk back to the lodge. We really need a vegetation list for the area!
In the afternoon we packed up and drove through the Manjolo Communal Area to the northwest corner of the park, finding a moderately shady spot to set up camp between kraals near Siganda Hill. It was interesting to see that Pied Crows had spread to kraals in this heavily populated area, evidence of anthropogenic changes.
3rd November
We did an early morning 3 km walk to the east to reach the Siganda River, then turned south and headed upstream into riverine vegetation. There were quite a lot of cattle here but they were in very bad condition. Around the kraals, boreholes had been sunk but the water was generally rather salty. These boreholes were palisaded and thirsty hordes of skeletal cattle gathered and pushed to try and get runoff whenever anyone operated the hand pumps, but this sunk into the mud inside the walls. It seemed obvious to me that sloping runoff aprons should have been constructed to channel this precious water out to the frustrated and suffering livestock!
Dry rocky river banks
The riverbanks up the Siganda were bounded by Diospyros senensis and Combretum riverine thickets with tall trees, including Figs, thrusting above them. The riverbed was rocky and dry with water mainly down near the entrance of the gorge. Further upstream we came to a stretch with water and pools with Lemna aequinoctialis duckweed and sedges, a good place to sit in the shade and take a break. Interesting birds we saw included the Racquet-tailed Roller, Livingstone’s Flycatcher, Broad-billed Roller, Trumpeter Hornbill, Ayres’s Hawk-eagle and African Hawk-eagle.
Ascending upwards the way was blocked by a waterfall but we found a steep path to one side where Wooden Bananas, Entandrophragma caudatum, were budding with fresh green leaves and old dried ‘bananas’ adorning the branches. A Natal Mahogany Trichilia emetica stood out as a mass of dark green foliage above the waterfall. Up here, on the boundary of the park, or in it, was a vegetable garden. It is rather a long walk from the communal lands below so someone was probably living here or nearby – this region was heavily poached in the ‘old days’, and the path showed that it was still being used for illegal entry. Leaving the path higher up we struggled through thick bush and followed a tributary to get close to a sheer cliff where we hoped to spot eagles and falcons. Nothing appeared while we sat eating lunch, despite the white streaks of mutes that showed the cliffs had been used for nesting at some stage.
Zambezi Tail-flower Strophanthus kombe
After our vigil we wound our way back down the tributary and the gorge, stopping on the waterfall bypass to photograph a Zambezi Tail-flower Strophanthus kombe and some Wooden Pears Schrebera trichoclada further on. A Verreaux’s Eagle riding the wind currents in the gorge was a wonderful sight, and back at our hot and dusty camp in the evening, Shelley’s Francolin tantalized with his call, a bird only occasionally heard but seldom seen.
4th November
Bird Plum Berchemia discolor in a barren field
We broke camp and headed back east again, following tracks closer to the base of the escarpment. The second bird species of the day was a pair of Common Mynas not far from the camp. We reached the sandy Kasanza River crossing but doubled back a couple of kilometres and parked in a field under the only tree unfelled within it, a Bird Plum Berchemia discolor. From this sparse shade we walked south to some riverine fringing a tributary of the Kasanza to do some transects.
Walking upstream the thickets produced some nice birds like Red-throated Twinspot and Eastern Nicator and a raptor nest in a base Knob-thorn Acacia nigrescens.
Woolly saucer-berry Cordia pilosissima
Leaving my tired teammate resting in some shade, I continued upstream into a gorge but the way was blocked some 500 m upstream by a waterfall. A scrambling Woolly saucer-berry Cordia pilosissima was in leaf and with baboons watching and shouting from trees and cliffs as I photographed Tamarind Tamarindus indica, Wooden Banana Entandrophragma caudatum and African Mangosteen, Garcinia livingstonei.
A swollen grey mass of trunks and short fat branches going in all directions on a cliff-face was perhaps an Adenia sp. I asked the baboon what he was climbing on but had no luck getting a coherent answer.
Calotropis procera
Bundled thatching grass in the gorge was evidence that locals were climbing the escarpment, probably into the park, to collect this commodity. We cut through kraals on a direct route back to the vehicle, finding Calotropis procera flowering and fruiting near a track. Crossing the Kasanza with a bit of excitement we proceeded on our way and it was interesting to find a Red-billed Oxpecker on a donkey on the other side, and near the Binga-Karoi road a Pied Crow nesting in a Baobab.
We turned south off the main road before the Ruzuruhuru and headed southeast. The river forms a braided floodplain up to a kilometre or more wide, with fields predominantly on the edges. Somewhere in here we stopped at a borehole, one with non-salty water, and filled up all our containers. I can’t recall what trees were growing here, but certainly Natal Mahogany and possibly also Fever-berry Croton Croton megalobotrys. At 14h00 we reached our campsite.
It was very hot, dry, rocky and barren! We left the cars on the river shelf and set up a few metres below where there was a group of scattered trees and some shade. As at our previous site, having a hammock was a boon; I didn’t have to clear rocks as the others had to do – mindful of scorpions beneath! We did a few transects in the afternoon, first across the floodplain, which had narrowed to some 300 m, and there were more Calotropis procera growing here.
Ruzuruhuru Gorge
We then headed south through riverine to the mouth of the Ruzuruhuru Gorge. Verreaux’s Eagle and African Hawk-eagle were nice sightings. The gorge is an impressive feature, the steep walls climbing 400 m from the riverbed to the ramparts 1 km across at the top – I have looked down it from the top but this was the first time my perspective was reversed.
We only went some 400 m up the gorge and it was slow-going navigating the rocks and boulders. Along the way we found a dead cow or two and also a baboon – there was the occasional spot with small pools of water. Unfortunately, I cannot give a list of the trees and shrubs seen along the way.
5th November
The next morning, we bumped and heaved our way in a semicircle to the foot of Tundazi. Along the way the saw a Wahlberg’s Eagle at a kraal with a Southern Yellow-billed Hornbill as its prey.
These transects were wearisome for my teammate – I suppose it must have been around 40°C in the valley! Much of the bush was grey and leafless, so, again, no tree list.
By lunchtime, we were at the dry and unappealing Siabuwa growth point trying to get a puncture repaired. Of interest were a few trees heavily laden with what may be a species of Erianthemum, a mistletoe.
By 16h00 we were happily sitting on the edge of the Mcheni Gorge viewpoint in Chizarira National Park, looking through the gap into the Zambezi Valley far below.
6th November
By 09h30 we were heading out of the Access Gorge on the long drive back to Harare.
EDITOR’S COMMENTS
My thanks to Jan Van Bel, Mark Hyde and “Ian-dianna” Riddell Jones for filling this issue of Tree Life with their stories; short or long, recent or tales from past times, please keep them coming.
TREE SOCIETY COMMITTEE AND CONTACTS
Chairman Tony Alegria tonyalegria47@gmail.com 0772 438 697
Vice Chairman Mark Hyde mahyde@gmail.com 0772 233 751
Honorary Treasurer Bill Clarke wrc@mweb.co.zw 0772 252 720
Secretary Teig Howson teig.howson@gmail.com 0772 256 364
Venue Organiser Ann Sinclair jimandannsincs@zol.co.zw 0772 433 125
Committee Member Jan van Bel jan_vanbel@yahoo.com 0772 440 287
Committee Member Ryan Truscott ryan.kerr.truscott@gmail.com 0772 354 144
Committee Member Sibusiso Malunga busimalunga@yahoo.com 0775 889 898
Tree Life Editor Linda Hyde Lmharwin@pentact.co.zw 0772 232 075
Tree Society Website https://www.treesociety.org.zw/
Tree Society Facebook https://www.facebook.com/groups/ztreesociety/
Flora of Zimbabwe: https://www.zimbabweflora.co.zw/
Flora of Tropical Africa: https://plants.jstor.org/collection/FLOTA
