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TREE
SOCIETY OF ZIMBABWE
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August 2004 JOURNAL
OF THE TREE LIFE MASHONALAND CALENDARSaturday
7th August. Botanic Garden Walk. Meet in the car
park at 10.45 am for 11.
Sunday 15th
August Our trip to the
Dyke is postponed till later this year, so we have decided
to return to one of our favourite venues, that is to Christon
Bank. We will try to walk along the Mazowe River to be in the riverine
vegetation, avoiding the gold panners if possible. Directions. From Harare take the Mazowe Road turning right
to Christon Bank at about the 22 km peg.
Follow the narrow and very twisty tarred road to
the end of the tar and park on the right.
Bring a chair and your lunch. And we will meet at
9.30 am. Saturday 28th August. Mark's walk will be at Greystone Park Nature Reserve
. To get there from the Borrowdale road turn right
into Harare Drive and continue for 4 kms then turn left
into Gaydon Road. After
the municipal offices on the hill and on the down slope
turn right into Halford. If you reach Ettington Road on the left you
have gone about 500 metres too far.
The reserve is about 200 metres down Halford Road
where we will meet at 2.30 pm. Saturday 4th September. Tom will still be away but Meg Coates Palgrave or Mark will lead the walk. Sunday 19th September. Monthly all day outing - hopefully to Jingo School - Chinamora, east of Harare. Saturday 28th August. Mark’s Walk – Glen Lorne. MATABELELAND CALENDARNothing has
been arranged for
August. Obituary: John Cottrill
We have just heard the sad news
of the death of John Cottrill in England on April 29th,
2004. John was a keen member of the Tree Society and was
also one of our trustees. We have the happiest memories
of the interesting outings made by the Society to his home
at Guitingwood. The following is a short obituary
written by his wife, Lilian. “John was born 1921 in Manchester.
Joined the Territorial Army while at school and was called
up for active service at the outbreak of war as a Second
Lieutenant. Joined the Indian Army and served in India,
Burma, Iraq and Iran. Achieved the rank of Major at 23 years
of age. Developed an interest in waterlilies whilst in Burma.
Was repatriated in 1945. Met me and married in 1946. Joined
his brother in the stockbroking firm they had inherited
from their father. Did not like the life or the Manchester
weather so emigrated to Southern Rhodesia in 1950. Worked
as a manager and then bought the farm, (Guitingwood). Built
fish ponds, (and more and more fishponds!) mainly to grow
waterlilies. Had over 40 varieties at one
stage. Developed a great interest in trees, made an arboretum
and joined the Tree Society. Formed a great friendship with
Rob Parre and learned a great deal from him. He loved the
visits we had from the Tree Society and meeting all the
people. We were expelled from the farm
in May 2002 and came to England in August to live in a two
room, upstairs flat, having very little money. Not a single
tree within a mile of us! John remained cheerful as ever
and enjoyed giving talks about Zimbabwe to various groups. He filled in his time by writing
his memoirs and managed to complete them before he died.
I don’t know if they will ever be published but there is
one publisher who is ‘interested’ and John had great pleasure
in writing them and in reviewing his past, not uneventful,
life. He suffered a cerebral Hemorrhage
on April 4th and died on the 29th
never complaining and still able to smile. What a good thing
he did not live and be an invalid! I heard recently from the Botanical
Gardens that Clive Wakefield had ‘rescued’ 32 waterlilies
from Guitingwood and they were now giving pleasure to people
at the Gardens. Perhaps they are a small memorial to John. I can hardly believe I have written
all that and not mentioned golf which really was a big part
of his life but would perhaps not be of interest to readers
of Tree Life. In the many letters I have had
from people they nearly all mention John’s love of nature
and desire to pass it on to others and his optimistic cheerfulness.
I do miss him! Much love. Lilian” BOTANIC GARDEN
WALK: SATURDAY 5 JUNE
2004 Nine of us gathered in the car park of the Botanic
Gardens on this Saturday morning. Meg Coates Palgrave kindly
agreed to lead us and it was a pleasantly informal walk
with no set subject and many contributions from others attending. A plant of the Tassel berry (Antidesma venosum) bearing the tassels of berries caught our attention
and someone mentioned that birds have a distinct order of
preference based on colour
as to which berries they will eat. Most favoured are black berries, next red and purple
and then with lower priority yellow and white and green.
This presumably reflects the probability of the berry being
ripe, with a black one the most likely and a green berry
probably the least likely. It is a bit unsatisfactory though
for trees whose ripe berries are white. Dalbergia melanoxylon was seen growing next to and
somewhat tangled up with Ormocarpum
zambesianum, and superficially the leaves looked somewhat
similar – both are 1-pinnate. However, the fruits of each
were both present and are very different: the Dalbergia
has a flattened pod with wings on the margins whereas the
Ormocarpum has
strongly segmented hairy fruits. The ormocarpum, although
it has been known for many years, has only recently been
described. Gardenia volkensii,
like many other gardenias, has its leaves and often its
branches in whorls of 3. It’s known as the Mercedes Benz
tree because the twigs in 3s slightly resemble the famous
car’s symbol. This particular tree was bearing fruit enabling
us to see the inferior ovary characteristic of the family
Rubiaceae. Meg mentioned an interesting thing about Croton gratissimus. This species produces
buds during the rainy season (c. February) and these buds
sit on the tree throughout the dry season and only open
when the next season starts. We also looked at Bivinia jalbertii. The petioles, like those of many Flacourtiaceae,
are often red (not obviously so in this case); the tree
trunk is a straight erect pole and the branches are held
in flat planes. It’s a distinctive and quite attractive
species, increasingly planted around Harare. It was an interesting session which I enjoyed very
much. I would like to thank Meg for a stimulating walk. Mark Hyde INDIGENOUS TREES IN FLOWER IN THE GARDEN ALL THE YEAR
ROUND. (Continued) Breaking
away from yellow two very spectacular flowering trees at
the other end of the spectrum are the wild-wisteria, Bolusanthus speciosus and the violet
tree Securidaca
longepedunculata. According to Trevor Gordon the
wild-wisteria flowers between 15th
September and 15th October. It certainly
is spectacular in full flower, before or with the young
leaves. The flowers are pea-shaped, blue to mauve in loose
sprays up to 30 cm long at the ends of the branches. I remember
coming back from South Africa in early October and seeing
them dotted about on the side of the road and into the distance
just before the Shell Garage outside Masvingo They seem
to occur naturally at a slightly lower altitudes than Harare.
It belongs to the pea family so presumably the seeds are
is quite easy to germinate. I grew one once having bought
a seedling but although I had it for 12 years it never flowered.
I think they need full sun and mine was in too much shade. In
the same garden I had a violet tree, but that was there,
I had not planted it. That is also a spectacular sight and
the with a wonderful scent. And the picked flowers last
well in water, up to two weeks and retain their scent for
much of the time. I think they usually flower towards the
end of October and into November. These can be tricky to
grow from seed. First of all I think the seed should be
put where the tree is intended to grow. Probably root disturbance
is fatal. Eileen McBean used to say the seed should be put
where the tree is to grow and covered with a cow pat, not
any sort of cow pat, a jersey cow pat. She kept a couple
jersey cows on her small holding and germinated wild-violet
seeds very successfully. In
July we are given hope that winter is nearly over with the
red flowers of the red-hot-poker tree, Erythrina abyssinica. Being red the flowers are probably pollinated
by birds. This is one of the luckybean trees. And I must
just mention Erythrina lysistemon the sacred coral-tree as we are now calling
it. It was decided that that would be a good name because
there is a tradition that when a man dies a truncheon should
be taken from a tree near his home and planted on his grave.
And why must I mention it. Once upon a time long ago and
far away my father bought London Farm at Nyanga. He built
London Garage which he did not run and he built London Store
which my mother ran and which probably provided some sort
of an income until the farm was able to do so. He also built
a stone house next to a circle of trees which became the
garden. Once it had been one of Rhodes’ outspan spots when
he visited his estate at Nyanga. That circle of trees consisted
of the sacred coral-tree and the common wild fig, Ficus burkei. I’ll come on to figs in a minute. When
Paul and I were married in in
September, 1957 at London Farm, my bouquet consisted
of flowers of sacred coraltree and Dombeya rotundifolia, wild-pear, which we collected and arranged
ourselves. My sister took care of all the wedding superstitions for us and added three little
yellow primroses from the garden. The flowers of the wild-pear
are interesting in that unlike most flowers when they have
been pollinated they the petals do not fade or drop but
remain on the flower to become dry and papery and function
as wings to distribute the seed. That explains why they
are so white to start with and then become dull and drab. For
March also with white flowers is the cluster-head protea,
Protea welwistchii but what
pollinates them is a good question. In Zimbabwe this species
can be confused with the african protea, Protea gaguedi, but is distinguished
by its unusual habit of producing 2–4 flowerheads together,
and the fact that its old flowerheads open out flat when
the seeds are shed, whereas those of the african protea
remain cup-shaped. They flower before Christmas. The leaves
of the african protea are mostly hairless, or sometimes
slightly hairy when young, whereas those of
the cluster-head protea start off densely furry and
even the older leaves have hairs, at least near the base.
Our three common proteas are actually easy to distinguish
between by when they flower. The northern protea, Protea angolensis comes
into flower after the rains are over about June and July.
That has broad leaves that are bluish green and hairless. So
what do we have Jan monkeybread Feb large-leaf
acacia Mar cluster-head
protea Apr indaba
tree fruit, common wild fig May confetti-tree June winter
senna, northern protea Jul red-hot-poker
tree Aug worm-cure
albizia, sausage-tree Sept. mukwa,
sacred coraltree, wild-pear Oct wild-wisteria
and violet-tree Nov baobab,
african-wattle, african protea Dec round-leaved
bloodwood The
month that does not seem to have anything is April so I
am going to put figs in there. A fig
is called a synconium,
syn - with, konos - cone, defined as the ‘hollow inflorescence axis of the fig’,
or as I would describe it, a receptacle, which has folded
over, closed and become hollow with the flowers round the
inside. If the flowers are enclosed inside a hollow, how are they pollinated?
They are pollinated by tiny members of the wasp family.
When I say “tiny” I mean “tiny”. One of our indigenous fig trees with quite
a large figs is Ficus
sur. The wasp that pollinates those figs is no more
than 2 mm long. As
a reward for pollinating the flowers of the fig the wasps
are provided with a haven in which their young can be raised.
This is a case of a real symbiotic relationship. At
the end of the fig, opposite the stalk, is an opening called
the ostiole. This is covered by scales placed in such a way that it is impossible
for anything to get out and very difficult for anything
to get in. Only the pollinating wasp has enough determination
to do so and often loses parts of her wings and legs in
the process. The
pollen was carefully tucked away in her pollen sacs and
so is quite safe. Having
gained entry, the little female wasp then takes the pollen
from her pollen sack and deliberately pollinates the female
flowers of the fig. Not only does she pollinate the flowers, but
she also she lays her eggs.
Some flowers are intended to produce seed and have
long styles. These are solid, preventing the wasp from laying
an egg in them. Some flowers have short styles with an open
canal so that the wasp can get her ovipositor into the ovules
and lay an egg. So
the tree has made provision both for it’s pollinator and
for itself to develop seeds. When she lays the eggs, those flowers are stimulated
to react by developing an abnormal growth, or gall, around
them. This provides
food for the forthcoming young. Then follows the normal
life-cycle of an insect. The egg hatches into a larva, which having
eaten enough, pupates and eventually the adults emerge. The
first ones to do so are the little males.
They are wingless, eyeless and have very reduced
legs, but are much more robust than the females and, although
they aren’t going anywhere, they do have an important role
to play. They identify
the pupae containing the female wasps, which they open and
then mate with the females.
They have another very important function.
The males all get together and bore a hole through
the fig wall into the outside world. The theory being that the fig is full of carbon
dioxide and they need fresh air.
The
atmospheric oxygen stimulates the females to rouse themselves. The first thing they do is visit the male flowers
of the fig, now mature and full of pollen. The female wasps deliberately fill their pollen sacs with pollen,
make their way though the hole that the males have made
to the outside world, fly off to find another fig tree of
the same species. Each species of Ficus
has it’s own species of pollinating wasp. The
figs, as a fruit, do not ripen until about five days after
they have had a hole made and the oxygen let in allowing
for the development of ethylene. So they do not get eaten until after the pollinators
have flown away. However,
not everything is simple survival for the fig pollinating
wasps, because for every species of pollinating wasp there
are often a number of wasps that parasitise them. The parasitising
wasp lays her eggs through the wall of the fig into the
flower with a pollinating wasp larva, but she must not lay
too many eggs otherwise there will be not be enough males
of the pollinating wasp to let them out of their potential
tomb. The
trees that are called sycamore in England, which are different
from the trees that are called sycamore in America, do not
occur in Biblical areas. So the reference in the Bible, to the sycomore
that Zacchias climbed, was probably Ficus sycomorus. These become large trees with a yellowish bark and
the almost horizontal branches bear the figs which do actually
taste quite nice. But the interesting thing is, that the
pollinating wasp of the sycomore fig does not occur in Biblical
areas. So the sycomore
trees must have been introduced from Africa, either as cuttings,
or seedlings, or they may even have been grown from the
seed of the figs that had been
imported. As there are no pollinating wasps, holes are
not made in the figs and so they don’t ripen, naturally. There
is the story of Amos, who said he was not a prophet but
as a simple shepherd and dresser of figs.
What did he mean?
If you owned a sycomore fig you would want the figs
to ripen and if you were wealthy you could afford to employ
someone to make holes in the figs to ripen them. And if you were a shepherd you would be able to sit on the branch
of a sycomore fig, keeping an eye on your sheep and earning
a few extra bucks nipping figs.
Do not let anyone tell you that figs are pollinated
by ants again. The
ants only get in afterwards! Meg Coates palgrave DARWENDALE: SUNDAY, JUNE
20TH, 2004
Our 3rd Sunday outing was to the home of Helen and
Albert Gray at Lake Manyame Park near Darwendale. A warm
welcome awaited us with tea, cakes and snacks served to
us on a rooftop in the wintry sunshine. The turnout was
good and the temperatures just slightly higher than the
Harare chill adding to the warmth of the occasion. Today was also the first day of an experiment for the
Tree Society. The Committee felt that not enough emphasis
was being given to beginners. It is difficult to lead a
group and cater to people who are just staring as well as
satisfying the more advanced people. It had therefore been
decided to split the party into two groups: one for beginners,
led by Rob Burrett, and the other for the more advanced,
led by me. This idea is somewhat similar to the "Ten Tree
group" idea which Dick Hicks initiated in which the
starters' group would study 10 trees and no more so as to
avoid the terrible Latin-name indigestion which can occur
on our outings. The two parties moved off into slightly different areas.
All around the house was the leguminous miombo woodland
typical of much of Zimbabwe. The altitude, according to
my GPS, was 1370 metres, definitely lower than Harare. As
one often sees, Brachystegia
boehmii (mufuti) was the commonest Brachystegia
at these altitudes and in fact, no msasa (Brachystegia
spiciformis)
was seen near to the house. Also accompanying the mufuti
was the ubiquitous Julbernardia globiflora
(the mnondo). All these legumes were in fruit and, of course, leaf,
and in the early stages of the walk we quickly revised the
distinctions between these common species. In effect, we then spent the morning walking round
the house; it was typical of the Tree Society that so little
physical distance was covered but we did have an excuse.
Not only did we look at almost everything, we also named
the species so that Albert could label the trees for future
reference. Some of the more interesting trees seen were as follows.
In winter, species of Vernonia
are quite frequently seen in flower; these belong to the
Asteraceae, the daisy or sunflower family in which groups of tiny
similar small flowers (florets) are grouped in heads so
as, in some cases, to mimic one giant flower head. Mostly the family consists of herbaceous species but
a few taxa are woody, namely, with us, Vernonia,
Brachylaena and
Tarchonanthus. Two of the commonest woody vernonias are Vernonia colorata and Vernonia amygdalina. These are mostly large shrubs
rather than true trees, although they can be trees on occasion.
Both are superficially similar and I must admit that I cannot
tell them apart at a glance. However, if the mature ovary
or achene is examined under a lens, the two can readily
be separated: V.
colorata has spherical gland-like structures only whereas
V. amygdalina has these and hairs as well. V. amygdalina appears to be the common one
around Harare, whereas V.
colorata comes in in drier sites at lower altitudes,
as indeed was the case here at Darwendale. Another species seen was Bauhinia petersiana subsp.
petersiana, which
is the white-flowered species, seen commonly in areas north
of Harare. This is usually a shrub but has definite climbing
tendencies and occasionally the branches may be seen to
coil in a tendril-like fashion. Two trees in the Sapotaceae were also observed. Both
of these, namely Mimusops
zeyheri and Englerophytum magalismontanum
have glossy dark green leaves and milky sap. However, the
shape of the leaves is different, the Englerophytum
has obovate or oblanceolate leaves and the leaves have a
noticeably silvery underside. After lunch, we set off to a slightly different area
across the road to Trudy Cashel’s property. The vegetation
here consisted of dry rocky woodland on a slope with plenty
of grass among the trees and many rocks. Here was msasa
as well as Brachystegia
boehmii and that
typically rocky species, Brachystegia
glaucescens. Here too was Strychnos
innocua, the
species with the powdery bark. Olax
dissitiflora was also seen and on crushing
the leaves the typical almond smell was (reluctantly) produced.
Some specimens of Euclea
natalensis were found which were relatively
large and tree-like. One specimen of Commiphora mossambicensis
was also seen. Herbs in the woodland consisted of the stout composite
Inula glomerata and the very common sprawling white-flowered Hypoestaes forskahlii. After a time we emerged on to a track and a few new
species were seen: Acacia
goetzei, Pterocarpus rotundifolius
and Albizia amara. All in all, it was a very enjoyable day. The concept
of splitting into two groups was a resounding success and
I expect that we will be doing this quite regularly, at
least when two leaders are available. Our grateful thanks go to the Grays for welcoming us to their home and providing
us with such magnificent hospitality. Mark
Hyde As Anne Mullin has emigrated to UK, Lyn’s book “Historic
Trees of Zimbabwe” will be available from Maureen Silva-Jones
- while stocks last of course. In Retrospect - Lyn
Mullin A CRY FROM THE EARTH The gem below was published in TREE LIFE No.137 (July 1991) under the title
"Roll-call of the Assembled Beings - From the Soil: I am the Living Earth. I am the
softened tissue of rocks;
baked by the sun, split by ice, carved by water,
and winnowed by the wind. I am interwoven by myriads of tiny plants and
animals that pulse and breathe.
I am the invisible universe of sparkling molecules
in the infinity of living soils that bless the mantle of
the globe. I am the carpet of the biosphere, the floor of the forest, the seed bed
of all plants; and
my living substance nourishes all roots and all leaves that
rely on the sun and rain to make green sculptures out of
clay. In the tall dim damp rainforests I house the bulk
of animal life, and support the endless upwards toiling
of trees and coiling of vines.
I am the bottom line of all grand symbiosis in forest
biology. I am the
source of mineral molecules in lovely flowers born high
among the birds in the forest canopy.
I am the energy sink, the lovely muddy frugal cemetery
for recycling all the forests' elements in the transitions
between life and death. Touch me, smell me, I am your ultimate quality of life in ecology's profound
cycles. See me,
hear me, you humans who pass me by with your round computer
heads rocking in the forest sky above me.
Spare me a thought, you humans who depend on me;
remember me, as I die before you, when you take away
my forest coverings and still the microbes that give me
life, me the Living Earth. Shift your gaze sometimes from the stars and remember the heaven beneath
your feet. Remember
me when the sun burns and the waters gouge me, be kind to
the forests that remain, and protect them from senseless
cuttings. Remember:
like me, you are already eroding.
Know this: like me, you are only dust when you are dead.
Accept this: unlike you, I am closer to re-creation as the
living earth, to genesis. (Len Webb 9.2.89) COMMITTEE MEMBERS’CONTACT TEL. NUMBERS HarareMark Hyde Home 745263 “ Cell 091 233751 Terry Fallon Home 778789 Adele Hamilton Ritchie Home 744651 Eva Keller Home 339368 “ Office 610029/33 Maureen Silva-Jones Home 740479 BulawayoJonathan Timberlake Home 286529 The Tree Society’s e-mail address is Previous issues: Aims
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