Tree Society: Outing to Christon Bank
Introduction
On Sunday, 17th November 2002, the Tree Society held an outing to Christon Bank, just north of Harare. A very small number of members attended (8) but it was nevertheless a very enjoyable day. Unusually for the Society, we walked a significant distance.
This web page is a bit of an experiment. I have never written up a Tree Society outing in this way before. The object is firstly to create an impression of the day - the sights and experiences of the bush on a hot day in spring and secondly to name and give some information about a selection of the species seen.
The pictures were all taken by me. Click on the small images in order to see the full versions.
In the car park
The eight members were Rosemary Browne, Rolf Chenaux-Repond, Werner Fibeck, Mick Fleet, Mark Hyde, "Jack" and Maria Jaklitsch and Maureen Silva-Jones. We met in the small carpark of the Christon Bank Botanical Reserve at 9.30 a.m. The car park itself is quite interesting, as it is itself amongst miombo woodland.
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In the woodland were several species of orchid: Eulophia cucullata, Eulophia livingstoneana and (see the next picture -although it's rather difficult to make it out!) Eulophia subsaprophytica. The whole plant is brown in appearance apart from the flowers which have a white lip. To judge from the name and its appearance, it presumably has no or little chlorophyll.
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On the way up
We went across the stream through reed beds, and ascended a fairly gentle slope on the other side. Here was Senecio coronatus, a fairly common pre-rains composite around Harare. To the right of it in picture 3 are some young brownish-red leaves of the mufuti, Brachystegia boehmii, a fairly common constituent of the miombo woodland here. Picture 4 shows a fruiting inflorescence of an Eriospermum, a genus so named because of its hairy seeds.
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The woodland we were walking through appeared to be mainly regrowth, with most of the trees of a similar, small to medium, height and probably of a similar age. However, one or two larger trees were seen from time to time. The next two pictures show typical scenes. The trees are mostly in young leaf at this season and have quite a variety of different shades of green. There has been some rain this year and the herbaceous ground flora is appearing.
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The next pictures show:
Berkheya zeyheri, a common yellow composite;
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Eulophia longisepala (very difficult to see in this picture);
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Tricliceras longipedunculata (two pictures) and ...
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Euphorbia griseola, a spiny euphorbia, fairly common in rocky situations.
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Picture 12 shows the group tackling the gentle ascent through the woodland. It was a hot day and quite hard work because of the heat but Jack had deliberately chosen an easy way up.
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... past some specimens of Eulophia cucullata
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... and some Dolichos kilimandscharicus. The flowers of this species typically appear before the leaves in the hot, dry, pre-rains season. Towards the end of flowering, leaves appear (this has been caught in this picture) and the plant then takes on its quite different summer appearance.
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At this point we reached a rocky outcrop slightly higher than the surrounding trees. In picture 15, the tree on the left is Brachystegia glaucescens, the Mountain Acacia, which is the typical miombo component in rocky places; the one centre-right is Hymenodictyon floribundum, the Fire Bush. You can just make out some of the erect flower spikes at the ends of the branches.
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The next three pictures show scenes from the ascent. Picture 16 shows a grove of Uapaca kirkiana, the mahobohobo tree; 17, the group resting in some shade and 18, a rocky outcrop with Brachystegia glaucescens growing on it.
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A somewhat larger tree than usual and also a slightly unusual species, Afzelia quanzensis, the Pod mahogany, here at a higher-than-usual altitude of c.1500m.
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At the top
At this point, we reached the highest point of our walk, 1530m per the GPS, where there was a large area of bare rock with views over rolling rocky Brachystegia glaucescens country and in the distance the Iron Mask range on the other side of the road to Mazowe which runs along the bottom of the valley.
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We then chose a shady place for lunch - under a glaucescens tree.
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The group, from left to right:
Jack, Rosemary, Mick, Maria, Werner, Maureen and Rolf.
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Pictures 26 to 36 inclusive were all taken in (or from) the open rocky habitats near the lunch stop.
Picture 26 is of Elephantorhiza goetzei; note the long pendulous dark pods.
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Picture 27 shows a general view with more B. glaucescens in the background; 28 another Euphorbia griseola and 29 another Elephantorhiza goetzei covered in pods.
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The next two are of Tapiphyllum velutinum, a Rubiaceae which is common in rocky habitats. In the second picture is a swallowtail butterfly.
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Ficus glumosa
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Two views of a commercial farm in the valley.
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Two pictures of a tree (B. glaucescens again) with apparently dead branches and strange tufts of foliage. The clusters of leaves looked a bit like a parasite (e.g. a loranthus) from a distance but they weren't. I assume that there was something wrong with the tree.
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On the way down
We descended on a somewhat steeper path through an area of large, scattered rocky boulders. Pictures 37 to 44 inclusive show the sort of terrain and its vegetation.
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A very common herb, seen throughout the day in the open woodland, was Becium obovatum.
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More pictures on the way down. The large leaves of Uapaca kirkiana can be clearly seen in these pictures.
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Picture 49 shows the distinctive leaf colour of young Monotes glaber; 49, the large leaves of a small Uapaca kirkiana.
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Finally we crossed the stream and passed a Hoslundia opposita in full flower.
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Back to the car park
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A nearby view point
The afternoon was finished off by climbing up on a small rocky hill near the carpark and taking some final photos of the views.
The next two are pictures over Thetford Estate. The pinnate leaves in picture 55 are Lannea discolor.
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Pictures 57, 59 and 60 show general views in the direction we had walked during the day. It's a surprisingly wild-looking area. Picture 58 shows the group on the rocky kopje.
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A wonderful day
It was not quite a typical Tree Society outing because we walked such a long way; normally we only cover a few hundred metres! Although no particularly unusual species of tree were seen, the day out of town in the hot bush, with friends, was a wonderful antidote to the hassles of our daily lives.
Thanks to Jack for planning the route and leading us and to Werner for identifying the orchids.
Mark Hyde