Tuesday March 1st : Botanic Garden Walk. Meet in the Car Park at 1645 for 1700 hours.
Sunday March 20th : Marsala Farm, Shamva District, and, to repeat the comments in the last Tree Life “a lovely spot with granite kopjes which need no climbing”. A bus has been arranged and will leave the Monomatapa Car Park at 0900 hours and Chisipite Shopping Centre at 9.10 hours. Fare $6.00.
BOTANIC GARDEN WALK : 1ST February 1983
Having examined Terminalia on our last walk we turned our attention to the other large genus in the COMBRETACEAE, Combretum itself. This is a genus we usually encounter on all of our outings, so it was excellent to be able to examine all of the 16 woody Zimbabwean species. All the COMBRETACEAE have simple, entire leaves without any stipules. Combretum is usually described as opposite or whorled but we have often found this an over generalization with many specimens distinctly alternate. The most characteristic feature is the 4 or 5 winged fruit which separates it from Terminalia whose fruit has only two wings.
We soon abandoned looking at similar species together, which would have entailed some backtracking but hopefully this summary will arrange the species as Tom Muller originally intended.
There are six climbing Combretum species and we started off with the most difficult, Combretum albopunctatum, where a process of elimination usually serves in identification. The leaves tend to be hairy with some purple in the young twigs. We noticed the maroon fruit with the characteristic 4 wings and tiny silvery scales. This climber is found in the Zambezi Valley but seldom within the jesse thicket. From there we wondered over to the nearby Combretum mossambicense with distinctive 5 winged fruit and large (+15cm) leaves. It also illustrated a typical Combretum feature where the leaf falls off near the base of the leaf-stalk, leaving a little petiole peg behind. This peg then grows into a long recurved spine which supports the branches while they sprawl and climb in other trees.
The only other 5-winged Zimbabwean species, C. obovatum, is also a Zambezi Valley climber, but has distinctly obovate leaves as the name implies. One of the spectacular sights of the day was the large number of white leaves on the flowering branches, an interesting flower substitute similar in function to the red leaves in the garden Poinsettia. Once again the petiole pegs are for climbing. Just alongside we examined the more widespread fire bush,
Combretum microphyllum (the old Combretum paniculatum) with very round leaves, a pointed tip and persistent pegs. Tom enthusiastically described the hot, dry Zambezi Valley in spring with the curving sprays of bright red stamens covering C. microphyllum on the alluvial sands and the leafless C. mossambicense covered in white stamens on alluvial soils and in old cultivated lands. A memorable sight.
The last two smaller leaved climbers, Combretum padoides and C. celastroides can be very difficult to tell apart. C. padoides has somewhat narrower leaves on a slender petiole and no elongation of the peg occurs. Unfortunately we were unable to find any flowers or fruit. This is a riverine species not found in the jesse, a useful field character as C. celastroides forms a dense thicket in the middle storey of the jesse. Fortunately the C. celastroides was covered in the characteristic yellow flowers (C. padoides has creamy white flowers) and those of us with good eyesight were able to find the persistent style on the end of the 4 winged fruit, a characteristic absent (or less than 5.mm long) in C. padoides. C. celastroides apparently turns a spectacular red in autumn.
Moving on to the more tree-like species, most of us are familiar with Combretum molle with its soft furry leaves that appear to fountain downwards. It is interesting to note that the branchlets peel in fibrous strips, in contrast to C. psidioides. Tom was proud to show us an ankle high sapling of the latter, apparently a difficult tree to cultivate. There on the small twiglet was a large piece of peeling bark. This individual originated from the Kalahari Sands of Matabeleland, and had narrow oblong leaves but apparently the Mashonaland sup species is very similar to C. molle but with peeling twigs, a feature to look out for in the future.
The mouse eared Combretum hereroense has small leaves that vary from wooly to glabrous as well as small fruit. The hairs on the undersurface impart a distinctive brown colour to this species. This can apparently grow into a large tree, especially along the Mazowe river. In contrast the big fresh green leaves of Combretum fragrans is seldom forgotten especially with the leaves in whorls of 3.
Combretum zeyheri is usually a walkover with its enormous 4 winged fruit, but these are unfortunately not always present. Tom explained how to look for the odd whorl of three leaves and demonstrated the rich orange slash in C. zeyheri. To test this we approached a labeled Combretum collinum and found both characteristics! A microscopic examination proved Tom correct, field ecology wins again! C. collinum is very variable and a devil without the dark coloured fruit.
The slash technique is also useful with C. apiculatum, the only species with a pale lemon yellow slash. Although the twisted and apiculate tip of the leaves is characteristic, the young twigs often have a peeling pattern resembling black net stockings, rather a spicy character. This tree is a dominant escarpment tree and can often be found in the less clayey mopane veld, we may well remember the specimen at Sable Park, Kwekwe, where we also saw C. elaeagnoides with its scales on the back of the leaves. Tom showed us the distinctive silvery grey growing tips in C. elaeagnoides.
We had a quick look at the riverine C. erythrophyllum but this tree lacked the characteristic ‘cat’s claws’ we saw at Kimcote and Serui. For roadside identification we noted the strange branching pattern of the lead wood C. imberbe where the terminal bud dies and a lateral shoot continues growing. The small silver leaves are borne on short side branches or woody spines arranged in an opposite decussate fashion along the stem.
Just to tidy everything up we looked at the false Combretum, Meiostemon tetrandrus. A tree that can be described as a herbarium nightmare as all the bent leaves fold in half and won’t press flat. This species only differs from Combretum in the number of stamens. The leaves are smooth and hairless. It forms a small bush or strangler in the deeper jesse thicket, often with C. celastroides but it does have characteristic twigs in the dry season.
Well, a bit overtime, but what a thorough coverage. Thank you, Tom, we really did learn a lot.
-Kim St. J. Damstra
And thanks to Kim for compiling these very comprehensive notes.
FEBRUARY 20TH 1983 OUTING TO JOHN GRAYLIN’S FARM,LOT 1 ULLADALE, MAZOE
The bus trip to the property of John Graylin at Mazowe was an appetizer for the day to come. As we descended into the valley, the woodland was dotted with bright spots of yellow flowers – suspected to be
Acacia amethothophylla (formerly A. macrothyrsa) which turned out to be the case. These trees really were the notable feature of the day; the very bright yellow orange flowers standing up above the outline of the trees. When not in flower this species is often mistaken for Peltophorum africanum, having similar large bipinnate leaves. However, the Acacia has pairs of black hooked thorns which distinguish it; and the flowers are typical Mimosoid type, lacking petals and having many stamens (pollen bearing or male parts of the flower) forming a “powder puff” of colour. Peltophorum is in sub-family Caesalpinoideae (Cassia-type) and the bright yellow of its flowers are the petals.
This time of year is a feast of flowers and fruits. The recent rains, albeit so late, made the whole area lush and green. Some of the many Pterocarpus rotundifolius were in yellow flower – a special bonus as their flowering times tends to be short, immediately following a heavy shower.
We contemplated a fine specimen from the verandah of the house whilst partaking a welcome tea provided by the Graylins. Then, following a brief look at the garden and many fruit trees, the morning walk began. Part of the property was dominated by Brachystegia spiciformis and Julbernardia globiflora, but the most common species overall was Acacia polyacantha, seemingly unmistakable with its whitish trunk and pairs of dark hooked thorns. I say ‘seemingly’ as we were soon arguing about a specimen thought to be Albizia amara!
The list of species in flower was somewhat longer than usual. Apart from those already mentioned, most notable was Azanza garckeana (family Malvaceae) with its large yellow hibiscus type flowers. Some discussion followed on identification of non flowering specimens. We always look for the “gland”, about halfway down the midrib on the back of the leaf. In young leaves this is very indistinct, being merely a grooved swelling. It turns dark with age however, and is therefore a useful aid to identification.
There were some sign of past cutting or disturbance to some of the area, but despite this, many trees of notable size had survived; namely one specimen of Cussonia arborea, and many magnificent Ficus thonningii. The Cussonia showed signs of fire damage to a height of more than 2 meters, probably explaining why so many species occurred only as coppice. The extremely corky nature of the Cussonia was no doubt a protection, as the tree was still in fine condition.
How introduced species can become naturalized was clearly illustrated by Duranta repens (forget-me-not tree) which was everywhere in flower and fruit. Birds are largely responsible for the spread, as they consume the orange fruits and later deposit the seeds.
Finally, after quite a walk in the heat, we came to the main objectives of the day namely a patch of Dalbergia melanoxylon (blackwood) and further on Heteropyxis dehniae (formerly natalensis) in flower. Heteropyxis is the lavender tree, aptly named for the fragrant aroma emitting from young or crushed leaves. This is not a species we often see, so it was a real bonus to have the flowers as well. Having walked all that distance for the splendid bonus of lavender trees in flower, we returned hot and thirsty to the trees and verandah of the house, only to find a large Heteropyxis next to the gate.
After lunch the survivors of the morning walk explored the stream area. And well worth while it proved to be. Apart from the relative coolness of the banks, the vegetation was quite luxuriant despite the relative shortage of rain. The stream bed was dry!
Securinega virosa formed dense growths; some of it in the white fruit which give it its common name of “snowberry”. Huge Combretum erythrophyllum lined the banks, many huge trunks leaning across the full width of the stream. We came across Maesa lanceolata which is found in such places as the Binga swamp forest, Bequaertiodendron magalismontanum and
Rauvolfia caffra (quinine tree) all more or less restricted to stream banks or forest edge.
Two mystery trees were later identified as Erythrococca trichogyne – which we thought may be a Clerodendrum, and Ekebergia capensis (family Meliaceae – mahoganies).
One last interesting find was Sesbania sesban, the river bean. It is described as a small short lived tree, but these had stems of 3” or so diameter. Elsewhere I have seen a specimen considerably larger, which was certainly not short lived.
Brian Best collected various ‘other’ plants that tree Society tend to trample underfoot. There was the extremely attractive Thunbergia crispa in bright blue flower. The flower stalk appeared to be a development of the axial bud, and the stalk lies along the midrib of the leaf, so that flowers appear to be borne on the end of a leaf. Also collected was Ceropegia meyeri-johannes, an asclepiad, which is fairly rare.
Many thanks to Brian and to Gill Masterson for organizing identification of the unknowns, and of course to the Graylins who provided a worthwhile venue and many pots of tea.
QUERY FROM LONG BEACH CALIFORNIA
Recently we had a letter from Michael J. Shields of Long Beach California who writes :
“In the January-March 1976 issue of the magazine “Trees in South Africa” (Vol. 27 #4) on page 91 a certain D.J. Pilbrough, who identifies himself as Director of T.P.C of Rhodes, states that a certain mixed stand of Eucalyptus grandis and E. microcorys at Inodzi, Rhodesia which was planted in 1905 had attained a height of “over one hundred meters or 330 feet” by 1976, with diameters around one meter.
Are you able to either confirm or refute this report? What in fact is the greatest height attained by these trees in Zimbabwe?
The reason for this inquiry is that I am gathering material for a book on the subject of remarkable trees, and as the article headline suggests, these eucalypts (if the report is correct) would establish a new record for rate of growth to that height, and height records for both species. Heretofore, the only eucalypts reported to exceed three hundred feet were E.regnans, E. globulus and E. diversifolia”.
We contacted Mr. L. J. Mullin, Divisional Manager, Research, of the Forestry Commission who has replied to Mr. Shields as follows :
The stand of E. grandis and E. microcorys at Inodzi Farm, near Penhalonga is well known to us and contains by far the tallest trees, indigenous or exotic, in this country. However, the report that appeared in the January-March issue of “Trees in South Africa” Vol. 27, No. 4, was exaggerated and the information given below sets the record straight.
- Location and area : The plantation covers an area of 0.44 ha and is situated adjacent to the Inodzi homestead at latitude 18 51’S and longitude 32 42’E. The altitude is 1350 m and the mean annual rainfall is around 1500mm (60”). The site has a westerly aspect and the plantation is on deep and very fertile doleritic soil. A stream runs through the stand and an old furrow, supplying water to the homestead, runs along the northern edge; the stream and seepage from the furrow have contributed to the remarkable growth of the trees.
- Species and history : The actual date of planting is uncertain but is generally thought to be 1905, possibly as late as 1920. The stand contains E. grandis and E. microcorys in a ratio of roughly 3:1 but the distribution of the two species is by no means even. The first major measurement was made in July 1957, and a subsequent measurement was made in September 1975. In the intervening period 70 trees were removed but no records were kept of what was felled. At the 1975 measurement there were 135 E. grandis and 41 E. microcorys.
- Growth rate : It is difficult to make comparisons of height, diameter and volume growth between the two measurements because of the removal of some of the trees. It seems that the diameters of the removed trees ranged from 38 cm to 81 cm but the largest trees in 1957 were still present in 1975.
- Heights : In 1957 the average height of the E. grandis was measured as 70.1m, the tallest tree measuring 85.2m. In 1975 their average height of the E. grandis was measured as 67.0 m, the tallest tree being 82 m. The average height of the E. microcorys in 1975 was 43.0 m and the tallest was 60 m. The height discrepancy between the 1957 and 1975 measurements of the tallest E. grandis was probably due to the extreme difficulty of measuring such tall trees accurately with simple instruments.
- Diameters : The mean diameter at breast height (1.3m) overbark of the E. grandis in 1975 was 77.07cm compared with 62.99 cm in 1957. The largest diameter tree in 1975 measured 133 cm, 18 cm more than its 1957 measurement of 114 cm. The E. microcorys had a mean diameter of 57.76 cm in 1975 and the largest diameter tree measured 127 cm.
- Volume : The total volume of the 176 trees in 1975 was estimated as 1 482,19 m3 which is equivalent to a production of 3 376 m3 /ha. The largest individual specimens of E. grandis and E. microcorys in 1975 were estimated to contain 31,79 m3 and 21,03m3 respectively. The mean annual increment of the plantation to 1975 was estimated as 48,23 m3/ha/annum.
- General : The large E. grandis in this stand are regarded by local and overseas foresters as the tallest in the world of any planted exotic trees.
ANNUAL GENERAL MEETING
The Annual General Meeting of the Society was held on Tuesday 25th January, 1983 at Selborne Routledge School, courtesy of Mr. N. M. Jones, the Headmaster.
The full minutes of the meeting will be circulated before the next AGM. However, it is my duty to inform members of the composition of the elected Committee as follows
Chairman Phil Haxen
Secretary Pat Walker
Treasurer Brian Best
Committee members Meg and Paul Coates Palgrave, Alec Dry, George Hall, Kim Damstra and Cherry Haxen
At a Committee meeting on 31st January Kim Damstra was elected Vice Chairman.
A vote of thanks was proposed for Meg Coates Palgrave as outgoing Chairman for giving the Society a wonderful year. This was thoroughly endorsed by members present, and I think it deserves a special mention in this newsletter as Meg has worked so hard in her two years of office and injected so much life and interest into our activities.
Thanks must also be given to the outgoing committee members Lola Irvine and Sybil Duncanson, who have served for a long time on our Committee and have always given of their best to the Society.
We have decided to enclose the Chairman’s and Treasurer’s reports with this newsletter while the subject matter is still fresh in our minds, rather than circulate them with the Minutes at the end of the year.
I look forward to a stimulating and successful year for the Society.
Last year when I started my report with “When I accepted nomination as Chairman I thought what fun it would be to arrange interesting outings” and this year I am repeating that and would like to continue that again it has been fun. And looking at the objects of the Society as set down in the Constitution I believe that the one to which I have contributed most is (6) To link together persons who are interested in trees. In this I think we have been most successful and perhaps we could add “and to further their knowledge”.
In January 46 of us visited Tom and Bobs Bayley at Danbury Park Farm where we visited the Wishing Tree, saw giant Pittosporum viridiflorum and, climbed in various ways, Mount Hampden. Some also returned to the homestead in various ways. They became sidetracked and missed the bus, but arrived just as a pick-up was going off to meet them.
We joined members of the Ayshire Branch in February at Nkodzwi Farm, Banket, home of John and Anne Duffield, where we combined botanizing with cave paintings, and our most exciting discovery of the day was the Large Leafed Ochna, Ochna gambleoides, Urera tenax and both Olax obtusifolia and Olax dissitiflora were among the other finds of interest, as was the rock painting of the white elephant.
Our venue for the March outing was “the patch of bush on the Airport Road”, also described as Queensway/George Road Woodlands, where we split into groups to see how many specimens each group could identify. Most groups had recorded over 50 by the time we gathered at our Mystery Tree on the anthill. One member did guess correctly that it was Scolopia zeyheri but changed his mind during discussion. This was quite an exciting find so close to the city centre.
And in April we visited Hugh and Barbara Taylor at Hopedale Farm, Shamva District where we recorded over 80 species and on the way home just managed to beat the rain for a view of the Cordia abyssinica on Woodland Farm magnificent in full flower contrasting with the dark lowering clouds.
The banks of the Umfuli River on Ijapo Estate, home of Roger and Anne Green, was where 40 of us met in May, where Diospyros squarrosa was the highlight of the day – in a day filled with interest, excitement and beauty and although not a tree, Abrus precatorius, the creeper with its little lucky beans deserves special mention.
Our June meeting was nearly a disaster. The wood cutters moved into the area we planned to visit during the previous week. Fortunately Arbor Acres own a large area of land and Mrs. Pat Bellingham was able to arrange for an alternative area where the trees were lovely and where the scavenger hunt with a botanical flavor was much enjoyed during the afternoon.
Stanley Farm, home of the Watkins family near Chegutu was the venue for our July outing. With a branch circumference of about 36 m (110 ft) Ficus sansibarica next to the house was distinctly eye catching, so much so that although tea was prepared when the bus arrived nobody appeared – we were all looking at the big tree. We walked through mopane veld found Capparis tomentosa in flower and then in the afternoon we found Maerua friesii, only the second time it has been collected in Zimbabwe, and incidentally Paul and I returned in August and found it in flower.
Our August outing was in the opposite direction, to Gilnockie Farm in the Arcturus district, where despite the devastation of a fire we had a lovely day as we wandered along the upper reaches of the Mapfeni River and were well rewarded by the beauty of the river and the wealth of riverine trees.
The September outing was a special occasion as it was the first time a combined outing had been arranged with Matabeleland Branch who were able to bring four car loads, despite the petrol crisis, and Mrs. Benedicta Graves was also able to be present representing the Ayrshire Branch. This was held at Sable Park, Kwekwe which is almost exactly halfway between Bulawayo and Harare. It was a long way to go so we started the day with a list of species we might see in relation to the km pegs on the side of the road. This I called Tree Typing in Transit and the long pod Cassia, Cassia abbreviata, with its sunny lemon flowers was a delight, all the more so because it was unexpected. Sable Park is a super place and I am delighted to reiterate that this Society is a life member now so has a permanent interest in it. The Aloe excelsa, Euphorbia cooperi and Olea europaea subsp. africana I am sure will remain in everyone’s memories.
And as I said in the Newsletter, after the bustle and excitement of the trip to Kwekwe our visit to Kimcote, Salisbury South District, in October was one of quiet relaxation and this is where we saw the dwarfs! Lannea edulis in fruit, Ochna macrocalyx in flower, Parinari capensis in flower and Syzygium huillensis in bud.
In November we had that day with a difference which, for those who looked forward to it, was not a disappointment and for those who had reservations about its success found it most enjoyable. We visited Springs Farm, Enterprise Valley, first Ian Turner’s garden abounding with all sorts of interesting plants and then a wander through a patch of his uncut bundu. After lunch we visited the Ewanrigg Herb Garden where Mr. John Smith Wright was good enough to give us a conducted tour and certainly held everyone’s attention for probably longer than I have ever been able to do.
I should like to take this opportunity to again thank our hosts for making us so welcome and for their warm hospitality. I am sure we all have full memories of Farm House Teas.
I have mentioned all our outings deliberately because that has been our main activity during the year and I believe that we are basically a recreational society and that most people join or continue their membership because of the enjoyment they get from it.
My enjoyment of the Botanic Garden walks has been tremendous and judging by the numbers who attend I am not alone in that. Here I should like to express our very sincere thanks to Mr. Tom Muller for showing us his trees and sharing his knowledge with us in his own inimitable way.
I have also had tremendous pleasure from the Learner Groups. Mrs. Gill Masterson has a wealth of knowledge which she imparts so readily and enthusiastically and the Learner Group outings have given me a chance to acquire some of this knowledge, which I have not had the opportunity of doing on our regular outings. I am sure that all those who have had the pleasure of joining this group will join me in thanking Gill for giving her time and sharing her knowledge with us.
The Newsletter plays a very important part in the affairs of the Society and unfortunately I have not managed to teach it to write itself. I am glad about that really because although time consuming, very time consuming – I enjoy sitting down at the dining room table surrounded books and reading up about the species we have seen, and working out what interesting facts I should write about. Here I would like to express my appreciation to Paul for all the help he gives me with the Newsletter. He is invaluable in helping me to avoid the pitfalls such as botanists who write on trees; conjuring up pictures of them rushing from tree to tree inscribing their thoughts and description thereon, or The Mashona use the wood for arrows and the Bushmen as Bows – poor Bushmen.
There has been a tremendous response to the Newsletter in the form of letters and comments, which has been most gratifying.
Recently we produced new Field Cards and our thanks go to Mr. Ken Blake of Grafotype in Bulawayo for an excellent job, well within the budget of the Society so that we are still able to sell them at 10c each. Records for the last 5 years of species seen have been kept and these were used as a basis for deciding on what to include in the new lists. These did not include Terminalia randii which we saw last outing.
New Application for Membership Forms have been produced incorporating our country and city name changes. Here thanks go to our son Tony for preparing the heading. I have been able to run off some letterheads using the same heading.
During October we deleted a number of names from our membership list because those people had failed to pay their subscriptions for the year, but most outings have resulted in new members joining so we have probably come out square in the end. I should just like to explain that because we have Family membership it is a little difficult to work out exactly how many bodies belong to the Society. Last month we sent out 200 Newsletters, including about half a dozen to similar Societies and between a third and a half were to Family members, so that gives some idea of the membership figures.
Mr George Hall has continued to play a very active part in the affairs of the Mukuvisi Woodland. In July we were offered US$1 000 towards a project of our own choice in the interests of furthering timber conservation, preservation or utilization, by the Environmental Liaison Centre which is based in Nairobi and which concerns itself with non-Governmental bodies with interest in Renewal Energy Resources of which they consider we are one George proposed a plan for a Village Woodlot and Woodland Regrowth Demonstration in the Mukuvisi Woodland, which is now in existence, and we wish him every success.
Binga Swamp Forest continues to be preserved thanks to the strenuous efforts of Mr Dick Petheram in coordinating all the bodies concerned. This now officially has its own subcommittee under the auspices of the Natural Resources Committee of the Arcturus Rural Council and the Department of Natural Resources.
The Branches have continued to receive encouragement and support as I feel this to be an important facet of the Society.
Paul and I visited Bulawayo and attended their outing on 1st January last year and visited the Ayrshire Branch in May for their outing to Mbagazewa. Mr. George Hall and I attended their special day for employees where George expanded on the virtues of allowing regeneration of the natural woodland which was enthusiastically received. Miss Pat Walker and I were able to attend their AGM where we were made very welcome.
The Committee met regularly during the year and I should like to take this opportunity of thanking them for their time and effort and I am sure you all will agree that special mention should be made of Mrs. Lola Irvine who, during a year of fuel crisis, always managed to obtain a bus, arrange the bookings and organize the security guard, all of which contributed in no small measure to the success of the year on which I am reporting. Miss Pat Walker deserves a medal, she has always been able to read my writing, has taken the sweat out of letter writing producing my scrawls impeccably typed.
And finally I should like to thank all of you for your interest, encouragement and support during my term of office. I have thoroughly enjoyed it. And now, particularly a thank you to Paul without whose help my task would have been impossible.
The Treasurer made the following points about the report :
- The Accounts had yet to be audited.
- The surplus for the year of $435.66 included monies earmarked for the Binga Swamp Forest and Mukuvisi Woodlands Funds and in fact the real surplus was $79.24
- A question was asked about the $755.28 for the Mukuvisi Woodlands and the Chairman explained that the Society had received a donation from the Environmental Liaison Centre of US$1 000 for use in a Renewal Sources of Energy exercise. Mr Hall had undertaken this in the Mukuvisi Woodlands and he explained the general theme of what he was doing and how the money was being spent. His report was received with great interest and he offered to show it to anyone who would like to see it.
- Mr. J. Reid said he thought this Fund should not be included in the income and expenditure section of the balance sheet, but should be itemized separately. The Treasurer agreed and said he had done this because this was the way the similar Fund, that of Binga Swamp Forest, had been handled last year. He would discuss the matter with the Hon. Auditor.
- The Chairman said that the appointment of an Hon auditor had not yet been finalized and suggested that this matter could be handled by the incoming Committee. This was agreed.