TREE LIFE

OCTOBER 2001

MASHONALAND CALENDAR

Tuesday 2 October Botanic Garden Walk Meet in the car park of the Botanic Garden at 4.45 for 5 pm where we will meet Tom and continue with the Figs.

Sunday 21 October. Closer to Harare this month as we spend the day in the fascinating mountains of Christon Bank. Jack and Maria Jaklitsch will lead us to the beacon from where the views are wonderful. The route to the beacon will take us through several different vegetation types. Don’t be put off, the pace will be that of the normal Tree Society walk. Bring a portable lunch so that we won’t have to get back to the cars till the afternoon.

Saturday 27^th October Mark’s next walk will be at Lilfordia School.  Ask any pupil or worker for directions to Mr and Mrs Williams’ house where we will meet at 2.30 p.m.

Tuesday 6 November Botanic Garden walk

Sunday 25 November. Succulent Plant Symposium 8:30 a.m. to 4:30 p.m. There will be nine demonstrations and illustrated talks sponsored by the National Herbarium and The Aloe, Cactus and Succulent Society of Zimbabwe ($100 per person.). For more information and to reserve your place phone 497586 or 494187 or write to 55 Glenara Avenue North, Highlands Harare.

MATABELELAND CALENDAR

No arrangements have been made for October. Contact Jonathan Timberlake if you would like to organize a future outing.

TREE SOCIETY WEB SITE

Late last year, one of our members, Odette Lind, offered on behalf of the Internet Service Provider Mweb to host a web site for the Tree Society. I am pleased to be able to inform you that the web site is now up and running.

To view it, direct your browser to: http://site.mweb.co.zw/treesociety

At present the site is a fairly simple one aiming to describe the aims and objectives and the activities of the Society, who is who and how to contact us. There is a very short history of the Society and, a little in arrears, all the newsletters since January 2001 have been placed there.

We are very grateful to Mweb for agreeing to set up and host our site at no charge.

I think that this is an exciting development which has great potential. If anyone has any ideas as to how we can make more use of the site, for example in attracting new members, publishing useful lists or images, please let me know.

-Mark Hyde.

ECLIPSE 2001

The solar eclipse of 21 June, viewed from the Mukuvisi Woodlands Centre, gave us about a 97.5% shadow on the sun, but this was enough to set off a few things that may be worth recording.

1. Trees

Two potted seedlings of Acacia abyssinica (Nyanga flat-top), about 70 cm tall, were made available for observation. Both of them (but one more than the other) showed signs of closing up their foliage in the way some plants do at the approach of sunset. When the sun was about half-emerged from the moon’s shadow the leaves started to open out again. These two plants were checked periodically throughout the event to observe their behaviour.

2. Birds

A small flock of 6-8 Laughing Doves was seen to come into a tree to roost as the eclipse approached its maximum, and they certainly started to settle down “for the night”. But I did not see what happened later when the moon’s shadow started to diminish.

3. Mammals

A female Duiker and a female Bushbuck also started to bed down as the eclipse approached maximum, but, again, I did not make any later observations on these two animals.

The larger mammals at the viewing platform had been gently driven there so that people could watch them during the eclipse, but there was so much chattering of adults and running around of children that any possibility of observing normal late-afternoon behaviour of these animals was lost.

-Lyn Mullin

BOTANIC GARDEN WALKS:  7 JULY AND 4 AUGUST, 2001

This is a rather belated, combined write-up of Tom’s walks in July and August in which he discussed figs. Ficus is by no means an easy genus to understand and despite a fairly recent revision (by C C Berg) still has a number of question marks and uncertainties surrounding it, although these mainly relate to the “natalensis group”. A further problem is that a significant proportion are rare Eastern districts species which we never see.

It is of course a genus we meet all the time on our outings and so it is useful to review it from time to time.

Firstly, some basic information about the genus. Ficus has the following characteristics:

• trees, shrubs, suffrutices, lianes or climbers (i.e. woody and often climbing on rocks and trees)
• aerial roots sometimes present
• milky latex (in most cases, but some exceptions!)
• stipules present (but these often fall quickly)
• the terminal stipule enclosing the bud is often prominent and taxonomically helpful
• leaves simple and usually entire (in rare cases, leaves are lobed)
• leaves alternate (but again, rare exceptions are opposite or whorled)
• leaves usually 3-veined from the base
• flowers are unisexual
• flowers are borne on a receptacle which completely encloses them (this is the unique “fig” structure)
• pollination by species-specific wasps

Tom explained that in order to name figs, the size and shape of the leaf was usually reasonably typical and helpful, as also were the hairiness and vein patterns, the size and persistence of the terminal stipule and of course the size and position of the figs themselves.

Can figs be confused with other species? Other trees with milky latex and alternate leaves in the same family, and in particular Milicia excelsa and Trilepisium madagascariense are somewhat similar, but neither of course have the enclosed receptacle of true “figs”. Outside the Moraceae, just possibly a species like Mimusops zeyheri might be confused but that lacks the prominent terminal stipule and again, in flower or fruit would look entirely different.

Outside of what I call here the “natalensis” group, the species seem to be reasonably well known taxonomically, but there is still much difficulty with that group, in which the following names are being, or have been, used in Zimbabwe: burkei, craterostoma, natalensis, rokko and thonningii. I shall attempt to deal with the “natalensis” group at a later stage; in this article, we shall only consider the others.

A useful and simple approach to breaking figs down into groups is found in von Breitenbach (1974). This is slightly out of date and moreover refers to South African species but I think it is helpful. It doesn’t cover all our species, so I’m not sure I can allocate everything, but it is at least a start.

The groups are as follows (with some brief notes):

CAPREIFOLIA GROUP (Sandpaper figs)

These are the species with exceptionally rough leaves. We have two, capreifolia itself and exasperata. Both of these are represented in the Botanic Gardens.

capreifolia(River sandpaper fig) tends to be a shrub, forming a dense thicket along low altitude rivers. It has a widespread distribution even occurring in the Central Division alongside the Munyati River in the Sanyati Communal Land at an altitude of 800 m. Often the juice is watery rather than milky and its other untypical fig feature is that its leaves may be subopposite or even whorled.

exasperata(Forest sandpaper fig) on the other hand is a very rare species of low-altitude forest in the Eastern districts. It has a smooth trunk, watery juice again (as we observed in the Gardens) and even rougher leaves than capreifolia.

SYCOMORUS GROUP (Cluster figs)

These are the only species which bear figs in often branched “inflorescences” on the old wood. (Other species as we will see bear figs on the old wood but the arrangement is of smaller clusters and the branching is not compound). Two species are involved, sur(formerly capensis) and sycomorus.

sur(Cape fig) is a common species of woodland and sometimes forest edges. It’s leaves are usually smooth (but may be roughish) and are relatively broad and often wavy-edged. This has very large branched fig-bearing structures, as long as 0.5 m.

On to F. sycomorus (Sycamore fig), which is a very widespread species usually in low-altitude riverine habitats, where it can be such a major feature alongside our great rivers. The leaves are rough (although not as rough as a real sandpaper fig) and the bark is a distinctive greenish-yellow.

SANSIBARICA GROUP (Fascicle figs)

This group, like group 2, bears figs on the “old wood”, but the figs are in small clusters, which often sprout out of cushion-like structures (chirindensis, polita, sansibarica)

chirindensis is a recently named species (in 1988 by C. Berg) plucked out of sansibarica. In Tom’s view, there is no doubt that it is distinct. It is a forest species, common in the Chirinda Forest, but also occurring in other E. Districts forests and in Kenya and the DRC. It has a glossy leaf with a long drip-tip, typically of forest species.

In the Chirinda Forest, it is a very large tree which surrounds and kills its host, leaving an extraordinary cylindrical free-standing lattice structure of Ficus stems.

Examination of both chirindensis and sansibarica suggested the following differences: the leaves of sansibarica are longer and narrower, sansibarica leaves have a straight base (chirindensis cordate), sansibarica has a much longer terminal stipule and it never occurs in rain forest. Tom believed there was also a difference in cushion structure.

sansibarica(Large-fruited fig) is a species of riverine forest and also occurs at the base of rocky hills where there is a bit more moisture. It has a much wider distribution within Zimbabwe than chirindensis.

politais another rare species recorded from E Districts forests.

We also looked at the South African species, F. bizanae, which occurs in the Transkei and Lebombo mountains. It was clearly a very similar taxon to sansibarica with figs borne on cushions but the leaves were somewhat different and the superficial appearance was of a different entity.

FISCHERI GROUP(Poplar figs)

Large trees with relatively large leaves which resemble those of poplars (Populus spp.) with a long petiole, drooping leaves and a triangular lamina with a cordate or truncate base.

fischeri(formerly kiloneura). Tom records that this is an exceptionally rare fig, found only once in Zimbabwe by Hal Burrows c.30 kms S of Mt Selinda. It is a species of forest and high-rainfall savanna.

ABUTILIFOLIA GROUP(Round-leaf rock figs)

Another well-marked group of figs with leaves which are very broad to almost circular and often with a cordate base. The species are confined to rocky places (abutilifolia – formerly called soldanella and tettensis).

abutilifolia(Large-leaved rock fig) (formerly called soldanella) has large leaves with sparse hairs.

F. tettensis(Small-leaved rock fig) has much smaller leaves which are more densely hairy.

GLUMOSA GROUP(Woolly figs)

Species with hairy leaves and/or young twigs (glumosa and stuhlmannii).

glumosa(African rock fig) (sonderi) is a fairly common tree of rocky places.

LUTEA GROUP(Giant-leaf figs)

lutea(sometimes known as quibeba or vogelii) has exceptionally large leaves and small fruits at the ends of branches. Tom remarked that it can occur in rainforest and also in forest outliers in woodland. It is often planted and makes a good garden plant.

INGENS GROUP(Pointed-leaf rock figs)

Two species form this group. The leaves have a truncate or cordate base and are relatively long and pointed.

ingens(Red-leaved rock fig) is probably the commoner of the two. It occurs in rocky places but sometimes in woodland.

F. cordatasubsp. salicifolia(Wonderboom fig) is similar but has a longer petiole.

VERRUCULOSA GROUP(Truncate-leaf figs)

Said to be a group with leaves truncate at the base. Our only species is F. verruculosa which is a suffrutex or small shrub occurring in damp grassland and by rivers and streams. Tom reported that its fruits are edible.

NATALENSIS GROUP(Strangler figs)

This is the difficult group. Several different treatments exist and what exactly is the current view is not clear to me. Perhaps others can provide an up-to-date opinion on this group.

OTHER SPECIES

Other species, not in the classification above:

bubu

This species is even rarer than F. vallis-choudae. It has yellowish bark, a broad, elliptic glossy leaf with a long petiole and occurs in low altitude forest in the Rusitu area.

bussei(formerly zambesiaca), in Zimbabwe, is a particular feature of the Zambezi River, where it occurs at low-altitudes on the older alluvium, just inland from the more recent alluvium. It is a large and handsome tree, often broader than tall. Its leaves are long and often slightly cordate.

nigropunctata(Velvet fig) occurs occasionally in rocky places and in woodland. Its leaves are softly hairy and it has a rather un-fig-like appearance.

ottoniifolia subsp. ulugurensis has been recorded from the Eastern Highlands Tea Estate area.

scassellatii(formerly called kirkii) is another forest species, which occurs only in the Eastern Districts with us. It has a large, elliptic, very dark green glossy leaf with a short acuminate tip and the fruits are beaked.

vallis-choudae(Haroni fig) is a tropical species, occurring in low-altitude rain forest. Tom mentioned that in Zimbabwe this effectively restricted to the Rusitu River and its tributaries. It has relatively large lvs and buttresses like many true forest species. The figs are relatively large and occur just below the leaves.

Once again, thank to Tom for a most interesting review of the species of Ficus.

References

von Breitenbach, J. (1974). The Wild Figs of Southern Africa. Monograph No. 2. Trees in South Africa, Volume XXVI, Part 3.

-Mark A Hyde

Which tree warns miners when there is going to be a cave-in?

The loblolly pine. Lumber from this tree is used as warning props which help support the roofs of mines. When these loblolly pine props are subjected to undue strain that might result in a cave-in, they begin to groan under the stress, thus giving the miners warning.

From “Trees Magazine”, Ohio.

A CRAZY SEASON?

Have you noticed something a little topsy-turvy about the current spring season?

Have you noticed that very many of Harare’s jacarandas are coming into leaf before flowering? Some of them look as though they will not flower at all this year, or perhaps have only a handful of blossoms.

Have you noticed Schizolobium parahybum (featherduster tree, sky’s the limit) coming into leaf before flowering? I have not seen a single specimen in flower so far this year, and many of them are already nearly in full leaf.

What’s going on in 2001? Have the gods gone crazy?

Is it a case of REPENT, FOR THE END IS NIGH!!!

-Lyn Mullin

LOWVELD IRONWOODS

I refer to John Wilson’s article in Tree Life 259 September 2001 with his observations on Androstachys johnsonii.

Like John, I spent many happy years in the south-east Lowveld and I always enjoy his articles taking me, as they do, down memory lane.

The vernacular name given by John is the one used by the Ndau people. The Shangaans refer to it as simbili.  When I first went to the Lowveld (l960s) I was working for Tsetse Control and was involved in the tragic bush clearing exercise. As mentioned by John, the Ironwoods did strike back and clogged airfilters in the vehicles used in the bush clearing was a serious problem as I recall.

Some extensive, almost pure stands, of Ironwoods occurred in the Guluene/Chefu area. These were bulldozed out, windrowed and burnt. Sadly, they haven’t recovered, but not all of them were destroyed. These simbili thickets provide the habitat for Crested Guinea Fowl among other creatures.

Not only were Ironwoods cut out in the tsetse control exercise, but all other trees considered as shade for tsetse flies, and this included the riverine fringes of the Lundi river from Chipinda Pools to the Chiredzi river. The

Chiredzi river was cleared as far as the old Chidumo Clinic. All the drainage lines running through the black basalt soils had the large trees removed.

In retrospect, this wholesale destruction of trees seems madness and, tragically, it didn’t work anyway.

This strategy had been adopted following public outcry at the former tsetse control measure of game destruction, which resulted in a commission of enquiry. Selective bush clearing had been carried out in East Africa as a tsetse control measure and John Ford (the man in charge of the East African exercise) was recruited from there to carry out a similar exercise here. As mentioned above, this didn’t work and selective game destruction was re-introduced, together with a spray programme.

The tsetse control measures adopted as a result of public outcry make me ponder on the democratic process. The wishes of an uninformed majority prevailed and caused the abandonment of a control measure that would have worked and, moreover, was reversible once the tsetse had gone (the rindepest epizootic proved this) in favour of the irreversible destruction of some magnificent vegetative assets, followed by non-selective poisoning of the environment with long-lasting insecticides (DDT and Dieldrin).

-Peter Taylor.

Concerning the article “The ecology of the Ironwood – Androstachys johnsonii” by J. H. W. in Tree Life No. 259, September, 2001, I wish to draw your attention to a factual inaccuracy in the text. On page 4, column 2, para 3, it was stated as follows :

“The tree clearing policy was soon abandoned in favour of pesticides sprayed from the air”.

This is not true. Aerial spraying against tsetse flies was never conducted in the Southeast Lowveld of Zimbabwe. Instead, bush clearing gave way to what is generally called ground-spraying by the tsetse control fraternity. This technique involves the application of the insecticide to the dry season resting and refuge sites of the tsetse fly by either man-carried motorised or pneumatic knapsack sprayers.

I make this correction in my capacity of a long-serving entomologist in the Branch of Tsetse and Trypanosomiasis Control, Department of Veterinary Services who was around at that time.

-Desmond F. Lovemore

Root Note:

Ironwoods are important trees from a beekeeper’s perspective, but of a negative aspect. Honeybees will readily forage on Androstachys johnsonii flowers but the honey produced from the nectar is inedible to humans as it causes a severe burning sensation in the mouth and throat!

Peter Taylor

In Retrospect :  MSASA SPRING COLOURS

This article, which appeared in Tree Life 259 September 2001, suggests the possibility of selecting Msasas for their Spring colours, presumably with a view to propagating them. I have found Msasas impossible to propagate. The seed will germinate but transplanting them has been a failure for me. Maybe Tom Muller has had some success with them?
Peter Taylor

MUFUTI UPDATE

TREE LIFE No 254, April 2001, carried a short note on out-of-season flushing of mufuti, Brachystegia boehmii, at Charmwood on the outskirts of Harare. This flushing was first noted on 19 March 2001, and it continued into May.

When we visited Charmwood on Mark’s walk on 25 August we wondered whether the new March-May flush would remain as mature leaves during the main flush due in September/October, or whether the March-May flush would be shed with last season’s leaves so that everything could start afresh in “due season”.

Well, guess what! The second of those options is happening right now. When I visited Charmwood on 5 September the situation had not changed from what it was on 25 August. But today, 10 September, revealed a completely new scene. The leaves of the March-May flush are turning brown and falling, and a new flush is well under way. So, it seems that mufuti at Charmwood is having a clean sweep, and getting rid of everything to start afresh – and there are some very good colours in the new flush, better than I have seen in most of the musasa this season.

Is this observation one for the books? I have not seen anything in the literature to indicate the B. boehmii, or any other z, sometimes has two flushes in a season. It does happen periodically in Pinus spp in the Eastern Highlands, but I have not noticed it before on such a scale in our indigenous trees. Any corroborating observations from anyone?

Lyn Mullin

SELWOOD FARM. MUTEPATEPA 19th August 2001

Yoland Nicolle welcomed 22 members at a perfect picnic site which John and Lance had cleared on the edge of the farm dam. After initial greetings the group set off, following John Cottrill to the opposite side of the dam to a well chosen area of unspoilt woodland.

Friesodielsia obovata. Photo: Bart Wursten. Source: Flora of Zimbabwe

Mark led and the first tree discussed was Friesodielsia obovata (annonaceae). A tricky one this when only in leaf, and easily confused with Bridelia mollisof the Euphorbia family – however some obvious differences were explained:- Friesodielsia obovata has obovate glabrous leaves which, when crushed, have a distinct resinous smell and the fruit is a dangle of red monkey fingers whereas the fruit of Bridelia mollisis a single berry and its leaves have a very soft and velvety feel, Bridelia cathartica which we saw has leaves with very marked rolled under edges and knobbly twigs. Plants in the Annonaceae family have entire leaves arranged in two ranks without stipules often recognized by a glaucous sheen, while those in the Euphorbiaceae family have alternate leaves with stipules. The leaves are usually simple, but if compound are always palmate and never pinnate. Hexalobus monopetalus (baboons’ breakfast) was the second of the Annonaceae family which we looked at but the fruit which resembles pink unshelled peanuts, had long since gone.

Monotes glaber. Photo: Bart Wursten. Source: Flora of Zimbabwe

Monotes glaber obligingly displayed its aid to identification – the gland or extrafloral nectary at the base of the leaf blade. Extrafloral nectaries supposedly provide food for ants which protect the plant against herbivores. Another tree which has these ‘glands’ is Parinari curatellifolia(mabola plum) but these are difficult to see being small and on the leaf stalk. Has anyone witnessed ants offering the service in exchange for this tasty reward?

We looked at Bauhinia petersiana not yet in flower but soon the countryside will be decked with the lovely white, frilly blooms. The red species – B. galpinnii occurs in the Shamva area not too far from this site, strange that it doesn’t spill over a bit to the Mutepatepa/ Bindura area. A surprise amongst the rocks was a lone Englerophyton magalismontana (Bequaertiodendron)(stem fruit), we usually associate this species with riverine vegetation. Close-by was a small Acokanthera oppositifolia in flower. It’s features include milky latex and alternate leaves with sharp bristle tips. The whole plant is said to be poisonous – remember arrow poison.

Cordia monoica caused a ripple of excitement through the group. We seldom see this tree – our last sighting being at Seddies Farm in Glendale. The leaves are round and as rough as sandpaper. For me the trunk is THE thing – fluted, bluish and peeling like a guava – beautiful.

The tongue test provided the rather scabrid feel of Gardenia ternifolia, – (G volkensii has smooth leaves) and against the clear blue sky we admired the outlines of the fruit of Steganotenia araleacea (the pop gun tree) and Kirkia acuminata.

Zanha africana often causes a momentary pause because it does not always stick to the rules. The leaves are supposed to be paripinnate but sometimes one of the end pair of leaflets either aborts or grows crooked giving the appearance of being imparipinnate. The leaflets are often asymmetric at the base and have a distinct varnished look on the underside. If the tree is mature there is no difficulty because the bark flakes off in round pieces leaving pink patches. We have noticed that often the leaves of young plants have a very obvious winged rachis and sometimes even a serrated margin.

A fair sized Pleurostylia africana was the next object of debate because the leaves were very slender and drooped gracefully, but on closer examination there was no doubt.

Mystroxylon aethiopicum. Photo: Bart Wursten. Source: Flora of Zimbabwe

This site yielded a great diversity of plants, amongst them some which we don’t often see such as Ormocarpum kirkia. Mystroxylon aethiopicum (Cassine), Philenoptera violacea (Lonchocarpus capassa),Pericopsis angolensis (muwanga) looking different – the bark was rough and reddish but all doubt was dispelled when Gill Masterson’s tip of the ‘dead branch on the right ‘ (or is it on the left?) was recalled,    (rubber tree) which seems not to bear fruit near Harare – perhaps it requires a lower altitude and warmer climate, Pterocarpus rotundifolius subsp polyanthus var martiniiis not unusual in this area – the leaves are very similar to P. angolensis(Mukwa) but the fruit (no bristles) and bark (smooth) resemble those of P. rotundifolius.

Mark showed us how to identify Vernonia colorata using a lens to establish whether the pappus is covered in glands or hairs. This had glands so colorata it was.

After a leisurely lunch while we admired Lilian and Yoland’s pen and ink sketches of the view and paged through part of Bobs’ collection of orchid paintings, a smaller group set off to explore a short way along the edge of the dam, and were rewarded with at least another dozen species not seen in the morning. Afzelia quanzensis (pod mahogany) with many pods but no leaves, Olax dissitiflora, Croton gratissimus, and Sterculia quinqueloba being of particular interest.

Many familiar species were seen, the total number for the day was 70.

Some creepers too, such as Adenia gummifera, Tinospora caffra, and shrubs – Tinneasp. in fruit as well as the fascinating blue flowered legume Eminia antennulifera with the clubbed antennae on the calyx tips.

An observation made by several members was that apart from the planted Ficus benjamina no other figs were seen on the walk.

All in all a very rewarding and happy day for which we thank the Nicolle family. We thank them too for preparing the splendid site.

-M.S-J

Just for mozz here are the origins of some generic names taken from Mr. W. P. U. Jackson’s “Origins and meanings of names of South African Plant Genera”

‘Bridelia‘ honours the famous Swiss muscologist Professor Samual Elisée de Bridle, 1761 – 1828.

Hexalobus’ from the Greek hexa – six; lobus – lobe. Members of this family have 6 petals

.Cordia‘ after Euricius Cordus, died 1535, and his son Valerius Cordus died 1544 – German scholars.

Gardenia’ after Dr. Alexander Garden who died in 1791, -doctor and naturalist from Charleston, S. Carolina.

Kirkia‘ after Sir John Kirk – explorer, naturalist and one time companion of Dr. Livingstone.

Pleurostylia‘ from the Greek pleuro – lateral (pleuron, a side); style; referring to the position of the style in the mature ovary.

Ormocarpum‘ from the Greek (h)ormos, a chain; karpos – fruit. The pod is linear, compressed and constricted at 2 or more sites

Diplorhynchus’ from the Greek diplo- double; rhynchos – a beak; referring to the fruit.

Dichrostachys’ from the Greek dichros, two coloured; stachys, spike. The upper bisexual flowers are yellow, the lower neuter flowers rosy-purple

Afzelia‘ named for Adam Afzelius of Upsala, 1750 – 1837 who at one time lived in Sierra Leone

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POLLINATION OF THE SAUSAGE TREE

Reprinted from Fairchild Tropical Garden Bulletin, July 1968

Sausage trees (Kigelia africana) are not rare in Miami. Since the original introduction by Dr. Fairchild more than 65 years ago they have been grown in many gardens for the curious sausage-shaped fruits. Yet there has always been a problem of getting them to bear.

The flowers are borne on long hanging stems several times during the year, but the main blooms seems to appear in late winter.. In their native habitat of Africa these flowers are said to be pollinated by bats which visit them in the evening or at night to get the nectar. In South Florida there are no bats so the flowers generally drop off without producing fruit. Enterprizing gardeners who want fruit to decorate their trees hand pollinate the flowers in the evening by collecting pollen from one tree and transferring it to the receptive stigmas of another. The trees do not ordinarily set fruit when pollen from their own flowers is used. thus one must have two trees or else a friend with a tree in order to get fruit.

At the Montgomery Foundation there are quite a number of these trees. In previous years only a very few fruits if any would set on them. This year, however (and to a lesser extent last year) many fruits have set. On one tree nearly 100 fruits have set without the aid of hand pollination.

The flowers on the trees have always been visited by large numbers of bees which are seeking the nectar so this cannot explain the increase. This year, however, I watched flocks of Spotted Breasted Orioles feeding in the trees in the evenings. They went from flower to flower and tree to tree feeding on the nectar in the flowers. It seems almost certain that they were the agents of pollination and are responsible for the heavy set of fruits.

The Spotted Breasted Oriole is a fairly recent introduction to Miami and their populations have increased rapidly. It seems apparent that as the population increases they will become even better pollinators of the sausage tree. The fruit of the sausage tree is not edible but resembles a large sausage in shape and colour. The fruit is woody with numerous black seeds embedded in the centre,. Squirrels have been observed chewing up the woody fruits to get at the seeds which they eat.

NB Comments and observations from Tree Society members would be very welcome

VERY COLD MUNHONDO?

Perhaps I have been blind to it all my life, but today, 15 September, I saw something I have never seen before. It was a cold, grey morning, and Anne and I were walking the dogs at around 8.30 am in the undeveloped ‘miombo woodland at Cleveland Dam. The munhondo (Julbernardia globiflora) flush was quite well advanced, and the leaves of most trees more or less up to full size, but, without exception, the leaflets of every tree were folded up against the rachis, and not held in their normal, open position. The musasa (Brachystegia spiciformis), on the other hand, had their leaflets open to the light (such as it was). The munhondo were behaving in much the same way as mountain acacia (B. glaucescens) does in the early evening when they fold up for the night.

This took me by surprise, and it is not as if I haven’t seen much munhondo lately. I have been among them nearly every day for the past week in a labelling exercise at Charmwood on the outskirts of Harare; the weather was very warm and the munhondo leaflets were all expanded in their normal position on the rachis, even though they were not up to their full size. None of my reference books mentions munhondo leaflets folding up the way I saw them today – so, can we have comments from our readers? Were the trees just feeling a little chilly?

-Lyn Mullin

MARK HYDE  CHAIRMAN