TREE LIFE

DECEMBER 2015

 

MASHONALAND CALENDAR

No Botanic Gardens Walk with Tom Muller this month.

Sunday Dec 6th: Christmas Social at Val d’Or:  Our venue again this year is Bill Clarke’s property, Val d’Or; thanks go to Bill for agreeing to host us.

PROGRAMME

9.30am to 10.15am  Tea

10.15am Scavenger Hunt briefing

10.30am  to 11.30am Team Tree Scavenger Hunt

11.30am to 11.45am Scavenger Hunt checking

12.00 noon to 1.00pm General Knowledge Team Quiz

1.00pm Lunch & Social

Please bring some Christmas fare to share for tea and bring your own lunch and a wine glass.  The Society will provide some wine for those attending.  Please bring any other drinks you may like, together with appropriate glasses.  Chairs and tables will be provided.

No PLANTED TREES OF HARARE for this month, hopefully we will have one for January.  –  Ed.

 

THE FIGS WITH TOM  Sunday, November 15, 2015

This month the third Sunday outing was to the Botanic Garden with Tom to look at the Figs in the genus Ficus, (the classical Latin name for a fig) in the  family Moraceae. This is one of the occasions when we really did a lot of walking, the fig trees are well spread out in the Garden and Tom had spent a couple of hours the previous day tracking them down. Thank you Tom it was great to cover so much ground and see so many species. The group did make double figures so Tom was happy and despite the heat, nobody dropped by the wayside.

The first one on the path to the restaurant and Education Centre was a challenge to us but Tom had to admit it was not indigenous to Zimbabwe being Ficus trichopoda, swamp fig, and it was amazing to see it here and doing very well. This is a tree that grows in swamps with horizontal branches with aerial roots, which this had but which usually go down into the water and become props for the spreading branches. At one time in South Africa it was Ficus hippopotami because of where it was growing, but was found to be the same as F. trichopoda which was an earlier name.

The next one as the path turned the corner was Ficus vallis-choudae, Haroni Fig, because that is the only place it occurs in southern Africa. The name comes from the Chouda Valley in Ethiopia where it was first collected. The figs are larger than Ficus sur and were lying underneath the tree.

And then we digressed to look at Burttdavya nyassica, a Rubiaceae species, a magnificent tree with big leaves and hairy fruiting heads that Tom had planted so it could be enjoyed from the restaurant. This grows in Mozambique and is a genus with only one species confined to eastern Africa.

The next stop was at that wonderful Sycomore Fig which has featured previously in a group photo. There was green fruit in little branched clusters along the main branches showing this to be subsp. sycomorus, different  from the other subspecies,  subsp. gnaphalocarpa which has figs that are borne singly in the axils of the leaves or leaf-scars.

Next to it were a couple of Ficus bussei, Zambezi Figs, wider than tall and well known at Mana Pools. The fruits were over and lying on the ground. The base of the leaves is deeply lobed with the lobes overlapping so that they almost look peltate with the petiole coming out of the back of the leaf.

Usually a spectacular so-called strangler, Ficus chirindensis, the Chirinda or fairytale fig, has been planted in the ground in the Botanic Garden and so is solid all the way up. Tom told us that when they start life in the fork of a tall tree they send their roots down to the ground and eventually grow so vigorously that they completely shade out the host tree and it dies. During our recent trip to Chirinda Forest we saw several and some of us climbed into the hollow trunk of the one illustrated.

Ficus chirindensis

Ficus chirindensis

The leaves of Ficus glumosa were too high up  for  us  to  be  able  to  see  that it was the Hairy Rock Fig with roundish leaves and found on many of the rocky kopjes around Harare.  This was fairly close to another rocky kopje species, Ficus natalensis subsp. graniticola, Granite-boulder Fig with leaves flattened or truncate at the apex and the midrib dividing and not quite reaching the end.

Across the lawn were two Ficus ingens, red-leaved rock figs, one in full green leaf and one with little pinkish fruit and the new red leaves. Behind the Herbarium were a couple of Ficus sansibarica, that Tom thought had died. Another bonus is that they too were in fruit. This tree is cauliflorous , bearing the fruit right on the branches on unbranched spurs. When not covered by fruit these appear as little knobs hence the common name Knobbly Fig.

On the way to Ficus rokko we ,or at least I, was side-tracked by Acacia goetzei subsp. microphylla in flower. This is something I don’t think I have ever seen in the wild let alone seen it in flower. Ficus rokko or Rokko Fig is another fig that sends down prolific aerial roots resulting in an expanding girth. The last time I had it measured it took 14 children with arms outstretched to go round it. One of them called it a magic tree.

Next was Ficus scassellatii, Crowned-fruit Fig, one I don’t know at all and am now delighted to know there is one in the Botanic Garden.  It has fruit with a little nipple on top but we didn’t see any.  This was just opposite a huge Draceana mannii, Small-leaved Dragontree.  We found what Tom thought might be Ficus tremula but the red on the midrib on the undersurface was puzzling.

Finally just outside the Education Centre we looked at Ficus bubu, which John Burrows, the Fig-book man, calls the Sulphur-bark Fig and that is a very good name for it as it has a very smooth pale sulphur-green to creamy yellow bark. In Zimbabwe this occurs only in the Haroni-Makurupini forest . This is usually an epiphyte or strangler and people who have been to Catapu will remember that spectacular stranger next to the road in the Inhamitanga Forest.

-Meg Coates Palgrave

 

OUTING TO NEW YEAR’S GIFT, CHIPINGE THURSDAY 5th NOVEMBER 2015

Plans having failed to go into Mozambique and explore the Ndzou Eco-camp in the Moribane Forest Reserve, with a view to exploring a potential destination for a Tree Society expedition, we – Graham, Bilal and myself – decided to travel to New Year’s Gift the day before the rest of the group arrived.  What a good move that was!

After a very easy and uneventful journey – toasted cheese and tomato sandwiches at Halfway House, buying mangoes, bananas and pineapples for the camp at Nyanyadzi, a paddle in the hot water at Hot Springs, visiting Birchenough Bridge over the beautiful Save River – we arrived mid-afternoon at the very green and luscious looking Tanganda Tea Estate’s New Year’s Gift Training School, where we received a warm welcome from Tonderai Chitungo and Francis Chingono and their staff.  All that was good news.  Then came the bad.

There had been no ZESA for a week and consequently every storage tank was bone dry and there was not a drop of water out of any tap!  There was also some confusion over the accommodation.  However, with the help of the staff, there were soon buckets of water in the rooms for flushing loos and washing hands.  A visit to Chipinge the next morning  procured more buckets, resulting in each room having two buckets of water.  Beds were moved around and re-arranged to fit our needs.  While the camp staff were making beds and filling buckets, we took the opportunity to visit Chipinge and the rest of the Tanganda Tea Estates.  It was a most interesting trip, both to see the Estates in operation, tea, macadamia nuts, avocados and coffee grown in profusion and also to see the complete devastation of “taken over” estates and burnt out areas.  We got back in time to welcome the rest of the party.  The group, as they arrived, took all the problems in true style and coped.  An erratic ZESA supply came back on Friday night, much to everyone’s delight but alas – it blew the water pump!!! But by lunchtime next day it was fixed and we all had water out of the taps.

New Year’s Gift Educational Centre

After an enjoyable evening meal Tony took those of us interested to look at stars – a great interlude – his “pointer” reached all the way to Heaven.

There were two botanising walks in the vicinity of the camp on Saturday, one into the dry woodland to the west of the camp and in the afternoon we had a very pleasant walk along the Tanganda River.  There will be a separate write up on these walks. We were more than delighted to welcome Doug and Tempe van der Ruit from Chimanimani on the afternoon walk.  They had come to be with us on our visit to Chirinda Forest the next day.  We were joined for dinner that night by Sue and Jamie Otterson and their little granddaughter, as well as Doug and Tempe – another happy evening.

Early breakfast and we set off for Chipinge where we met up with Dave and Irene Meikle and Peter and Marianne Buttress and proceeded onto to Chirinda.  The forest has lost none of the magic I remembered from a childhood visit and a visit in the 1990s with my husband Desmond.  Not for me to try to find the right words to describe it all, there will be a write up for that day too.  We had a picnic lunch in the forest and then set off to the camp site on the other side of the road which looked to be in very good nick and the botanising was wonderful.  If the road had not been so bad this would have been the destination for the last day, I feel sure.  It really needs another visit and more time.

Chirinda forest

Chirinda forest

Monday – all the group were a little jaded after the very long, hot day on Sunday.  There was a local botanising excursion around the camp and in the afternoon the group was entertained to tea and botanising in the Otterson’s garden.  While this was going on a visit to the local road side market up the hill to procure fresh fruit for lunch and the next day’s breakfast was profitable.

After breakfast on Tuesday we all packed up and headed for home – a long drive and it was very hot, however we had another paddle in the hot springs and more mandatory cheese and tomato sandwiches at Halfway House and that broke the journey home.

It was a good experience all round, I hope.  I certainly found it so.  I would also like to say how very grateful I am to the group for all their support and understanding on all the issues they put up with – ZESA, no water, monotonous breakfasts etc !!

-Mary Lovemore

 

SATURDAY, 7 NOVEMBER 2015

The first full day of our Chipinge trip and we decided to have a ‘local’ day and explore the area around the New Year’s Gift estate.

In the morning we set off on foot from the Training Centre. The altitude was around the 800m mark, not particularly low, but low by Harare standards, so it seemed a hot walk. The season has been very dry so far (are we in for a drought as is predicted?), so there was little herbaceous flora. However, the trees were bursting into flower and leaf.

Within the Training Centre compound we came across a flowering Xeroderris stuhlmannii (Wing Pod) bearing white pea flowers. A few old fruits were seen and these were flat surrounding a central seed with the fruit margins bearing a prominent winged rim.

Further on, we came into more natural woodland. Here were Acacia nilotica (the Scented Thorn), Phyllanthus reticulatus (the Potato Bush), Commiphora mollis (Velvet-leaved Corkwood) and Philenoptera violacea (the Rain Tree).

Although more usually a species with prostrate stems, we came across Tylosema fassoglense, the Creeping Bauhinia, ascending into a tree with its clusters of yellow flowers. On the subject of bauhinias, in the area were flowering plants of the beautiful Bauhinia galpinii, (the Red Bauhinia or Pride of the Cape) already in flower.

Common in the woodland was Maerua juncea, a scrambling or climbing species; in this case it was the subsp. crustata which we saw. Subsp. crustata has rough fruits whereas the more common subsp. juncea has completely smooth ones.  The very young flowers and leaves posed quite a challenge even for well-known species as we were not familiar with the trees in that state. On the positive side, it enabled us to get some new photographs for the Zimbabwe Flora website.

A frequent tree was the Mane-pod, Dalbergiella nyasae and we were fortunate enough to find some pods with their mane-like margin. The afternoon was spent in the very different shady environment of the riverine forest alongside the Tanganda River.  This was slightly lower altitude than the morning walk at 795m.

Here were frequent specimens of Trichilia emetica (the Natal Mahogany or Banket Mahogany). These bear large glossy imparipinnate leaves and have more or less spherical fruit with a tapering base (or stipe). The fruit are the easiest way to separate T. emetica from the similar Forest Natal Mahogany, T. dregeana, the fruit of which do not have the distinctive stipe.

Another characteristic tree of lowveld rivers seen was Breonadia salicina, a species in the Rubiaceae (the Coffee family) which has whorled leaves and inflorescences which are spherical in shape. Kigelia africana (the Sausage tree) and Afzelia quanzensis (Pod Mahogany) were also present.

Another medium-low altitude species seen was Annona senegalensis, the Wild custard-apple. The prickly climbing species, Smilax anceps, was found in the forest shade. Common throughout was a non-native Albizia, which had been identified on previous trips as Albizia procera. Specimens were taken and it is intended to try and confirm this name.

A number of specimens were collected on this day which are yet to be identified. Specifically, three species of the Loranthus family were found which may be of interest.

I would like to thank Tom and Meg for the interesting discussions in the field. A special thanks to Mary L., who organised the outing.

Mark Hyde

TO BE CONTINUED….

Mary L. has been valiantly scanning and now retyping the old Tree Life editions so that we have digital copies for our records.  A real labour of love Mary!  She came across this interesting article.

Ed

Tree Life No 98,  April 1988

LUCKY BEANS: NOW USED IN MODERN MEDICINE

 

Erythrina lysistemon (formerly E. caffra). Photo Bart Wursten, Flora of Zimbabwe

Coastal Coral Trees (Erythrina caffra) have been the focus of scientific and industrial research for the past three years in Cape Town, Pretoria and the Eastern Cape. Members of the Atalaya Branch were drawn into a massive effort to collect the “Lucky Bean” seeds of this species of tree and this year achieved great success in proving that a crop of many tons is available for the picking.

It was important for the South African Inventions Development Corporation (SAIDCOR), an off-shoot of the CSIR, to know this because it had commissioned a Cape Town pharmaceutical manufacturer to produce on an industrial scale the newly discovered compound ETA (Erythrina protease inhibitor). This is an essential factor in isolating a new drug with remarkable properties for the instant treatment of coronary thrombosis and stroke.

The story begins with a visit by Dr Frans Joubert of Pretoria to Professor Eugene Dowdle, head of the Department of Clinical Immunology, Cape Town University, four years previously.  Dr. Doodle, his staff and senior students, were trying to find a better way to isolate the experimental anti-clotting drug tPA (tripsin plasminogen activstor) that was proving difficult and expensive to produce and not completely satisfactory anyway.  The immediate project was to find a bean protein that would perform better than soya been protein, then being used for the experiments.

On that important visit to Cape Town, Dr. Joubert, a CSIR protein scientist from Pretoria, pulled out of his pocket a small quantity of Erythrina seeds and gave them to Professor Dowdle, suggesting that they be tried.  Eureka! The Coral Tree protein worked marvellously.  It made the isolation of tPA a more direct process yet one that was more economical.  Moreover the tPA thus produced had the remarkable property of “homing in” immediately on the clot that caused an arterial blockage, whereas existing anti-clotting drugs could spend vital time searching the vascular system of a dying patient for the clot.  In addition tPA produced no side-effect haemorrhages which were a risk involved in the use of earlier anti clotting drugs.

The discovery created an immediate demand for a large quantity of Coral Tree seeds and Professor Dowdle made an appeal in a National Sunday paper for members of the public to collect and send him the red-and-black “Lucky Beans”. No particular species was mentioned. However, the response was disappointing.

Months later in 1985, SAIDCOR directed a second appeal specifically to the Eastern

Cape, home of Erythryina caffra. It decided to concentrate on the orange-flowering Coastal Coral Tree in order to remove a variable from the experimental studies.

SAIDCOR appointed Mr Glen Harvey, retired scientific adviser for South Africa in the Shah’s Iran, to organise and co-ordinate the collection of the seeds in Port Alfred, Port Elizabeth, Grahamstown, Alexandria, East London and the surrounding areas.

In looking for a co-ordinator for Port Elizabeth, Mr Harvey was referred to us, a committee member of the Atalaya Branch of the Dendrological Society.  As a retired journalist and writer of a weekly column for naturalists and gardeners in the Eastern Province Herald, I was able to mount a fairly intensive publicity campaign.

That year the mass of beans collected (for which SAIDCOR now paid 50c a kilogram) rose to more than a ton. In 1986 other committee members of Atalya also were running depots for seed collectors at their homes in Port Elizabeth. The total collecting in Port Elizabeth was about a ton and in the Herald’s complete circulation area about three tons.  By now most of the actual collectors were rural Africans, many of them unemployed, so the project acquired a socio- economic significance.

In 1987 a halt was called when the project had escalated to a total of 4613 kg, most of it collected in Grahamstown, Alexandria; Port Alfred and Port Elizabeth from the thousands of Erythrina caffra trees on sidewalks and in gardens.

Dr Ore Safriel, project manager for SAIDCOR, regards the seeds as a national resource of great potential value. She says there is world medical interest in EIA, as it offers human control over the dissolving of clots. The drug is now going through the process of testing for human use by the international food and drug administration.

As the trees from which seed was harvested in this project have nearly all been planted, seed collection had no detrimental environmental impact.

Bob Nixon     Dendroon July 1987

 

TONY ALEGRIA CHAIRMAN

Tipuana tipu flowersFraxinus excelsior - the European Ash