TREE LIFE

October 1996

 

MASHONALAND CALENDAR

Tuesday 1st October. Botanic Garden Walk at 4.45 for 5 p.m. We will meet Tom in the public car park of the Gardens. Tom will be discussing the Hippocratea which we find tricky, so his help will be very welcome. The list on page 8 would be useful on the walk. There will be a guard for the cars.

Saturday 19th October. Mark’s Walk will be alongside Glenara Avenue South in Hillside. To get to the meeting point, take the road (Hillside Road) off Glenara Avenue South which goes off opposite the turn-off to the Mukuvisi Woodlands. After a few metres, turn left into the small service road (Mundy Drive) which runs south parallel to Glenara Avenue South. We will meet a few metres down Mundy Drive at 2.30 p.m.
The reason for visiting this location is to examine a remarkable crop of alien plants which has come up there. The plants appear to be of European origin and include striking purple Radish plants (Raphanus sativus) and three other rarely seen crucifers: Rapistrum rugosum, Sisymbrium orientale and Carrichtera annua. In addition, there are a number of introduced grasses.
Incidentally, both the Radish and the Rapistrum appear to be coming up in many places by roadsides in Harare. Although both have been recorded in the past, y chance, the verges have been cut or the plants are all dried up, we will explore somewhere else in the vicinity.

Sunday 20th October. Our previous visit to Msasa farm in the Barwick area was blessed with two cloud bursts. It is unlikely to rain at this time of the year, and the challenge could well be to test our skills on identifying trees, with the help of habitat, bark, or from newly unfurling leaves. We plan to walk along the edge of the dam and then cut into the kopjies. On the day of the recce the bush was alive with birdsong.

Tuesday 5th November. Botanic garden walk

 

MATABELELAND CALENDAR

Sunday 6th October. Visit to Clem von Vliet’s old garden at Douglasdale, now the garden of Mrs. Bott. Morning only, meet at Girls’ College car park at 8.00 for departure at 8.30 a.m.

Monday 14th October. Study Session.
Starting in October, on the second Monday of every month we will be looking in detail at two or three species (if trees, succulents or other interesting plants on Circular Drive, meeting at 5-5.15 p.m.

Friday 1st to Sunday 3rd November.  To Tom and Mary Raub’s Kana Estate near Gwaai. Please phone Tom  or Anthon  if you wish to go.

 

EUCALYPTS IN HARARE

In March 19951 produced some notes for Tree Life on the eucalypts that I knew were present in Harare, as well as some additional species that I felt were probably present even though I had not actually seen them. Very recently I have come across a very fine group of Eucalyptus maidenii within the City limits, and a few months ago I was able to confirm the presence of Eucalyptus melliodora.

Eucalyptus maidenii (page 29 of the notes) can be seen on Teviotdale/Alpes Road on the City side of the Pomona Quarry. There is a group of handsome specimens on the east side of the road immediately in front of ‘The Cabbage Patch’ vegetable and fruit shop and the ‘Lorna Doone Dairy’. Alongside is the ‘Country Garden Nursery’. These Eucalyptus maidenii are as good as any I have seen in the Eastern Highlands.

Eucalyptus melliodora may be seen in the grounds of the ZRP quarters at the Highlands police station. The species was described on page 35 of the notes. I was fairly sure for some months that the species was Eucalyptus melliodora but had been unable to find good specimens of buds to confirm the identification. The capsules are not always easy to identify because the disc and valves are usually obscured by a persistent staminal ring and Eucalyptus melliodora is not the only eucalypt that has this feature.

-LYN MULLIN
P.S. I had indicated in the notes that perhaps 130 species of eucalypts had been introduced into Zimbabwe. In fact the number is 199! I have just done a thorough search through old records.

 

BOTANIC GARDEN WALK: 3 SEPTEMBER1996.

16 people gathered for Tom’s Botanic Gardens walk; now back in its Tuesday evening slot. The subject was lowveld trees.

Combretum mossambicense. Photo: Bart Wursten. Source: Flora of Zimbabwe

A short walk took us to a climbing species, Combretum mossambicense, nearly in flower. It is a common lowveld species, occurring in old lands, in degraded land and in riverine vegetation. Later, it will produce the typical winged Combretum fruit, although, somewhat unusually this species is 5-winged.
A striking Acacia nearby was covered in flower spikes, but no leaves. The thorns were curved and in pairs and indeed, the whole appearance of the tree suggested Acacia nigrescens, but in fact it was Acacia galpinii. This species is common in Zimbabwe, occurring usually in riverine forest but also on termite mounds on the highveld.

Bridelia mollis. Photo: Bart Wursten. Source: Flora of Zimbabwe

The differences between Bridelia  mollis (Euphorbiaceae) and Friesodielsia obovata (Annonaceae) were discussed. It was agreed that if either species is in flower or in fruit there would be no difficulty in separating them, but what if they were in leaf only as they were here. Two approaches proved workable. The Bridelia has stipules (or stipular scars when the stipules have fallen off) which the Friesodielsia does not. Furthermore, the leaves of the Annonaceae are aromatic when crushed, which the Bridelia is not.

Finally, it was agreed that the Friesodielsia leaves appeared to be just a bit more obovate than those of Bridelia.  Tom showed us two closely-related species of Cordia, namely Cordia goetzei and Cordia mukuensis. Both have remarkable fluted bluish peeling trunks. According to the distribution in Flora Zambesiaca, Cordia mukuensis is confined to the Northern Division, whereas Cordia goetzei is in both the Northern and Southern Divisions.
Before darkness fell, a young (31 years old) remarkably large Baobab tree was examined. It was leafless, with a few pendulous fruits present. Tom mentioned that it had flowered from 15 years old. Lastly, Tom recounted his experiences of the devastation caused by a tropical cyclone in the coastal forests of Inyamatenga.

Once again, thanks to Tom for a splendid walk.

-MARK HYDE.

 

VISIT TO MASVINGO AND NYONI HILLS 8 AND 9 AUGUST 1996

On the 8th of August a party of four from Bulawayo set off for Masvingo where we were to join the party coming from Harare. It was decided to go via Lake Mutirikwe using the back road through the communal land. This road winds through the granite hills leading to the lake and the countryside here is really picturesque. Just after passing through Zvishavane on the way to Masvingo we stopped to look at Aloe parvibracteata which was in full flower. The pinkish red flowers of this species resemble those of Aloe zebrina which usually flowers from January – April depending on locality and Aloe greatheadii which also flowers in winter but is usually a much larger plant and hardly ever produces large groups from suckers which Aloe parvibracteata does in abundance. It was also interesting to find Cissus cactiformis which resembles Cissus quadrangularis but with thicker stems. We stopped near the dam wall at Lake Mutirikwe where we spent an hour or so looking at the trees, aloes (a few of the Aloe cameronii were still in flower, and Aloe excelsa was in full flower), Euphorbia and other succulents. The writer was able to collect seed of a Senecio sp. and Hymenodictyon floribundum which was plentiful on the rocks near the dam. Seed of Albizia gummifera was also collected. We left Mutirikwe and drove passed the entrance to Great Zimbabwe. We were a little early for the rendezvous at Riley’s Truck Stop so we waited around for a while for our host Audrey Riley at whose Guest house we would be spending the next two nights. Our accommodation of bed and breakfast was not the spartan accommodation that Andy had led us to believe it would be. He must have been joking I’m sure.

After a lovely full breakfast we set off for the south side of Nyoni Hills. A few kilometres south of Masvingo we again saw many patches of Aloe parvibracteata in beautiful full flower. We reached the Chiredzi turnoff from the Masvingo to Beit Bridge road and a short distance down this road we again turned left at a Rio Tinto sign which looked a bit like the Japanese flag (a red sunburst). After a bit of back-tracking we approached a limestone ridge in a river gorge which Andy had been told might be worth investigating.

Maytenus mossambicensis. Photo: Bart Wursten. Source: Flora of Zimbabwe

Almost immediately we came upon a plant which was new to me, Maytenus mossambicensis, very distinctive and in beautiful autumn colours. The river produced several unknowns which went back with Maureen for identification in Harare. Stadmania oppositifolia, Ekebergia capensis and Alchornea laxiflora were notable amongst the trees we were able to identity. Jonathan had something of interest in some specimens of Acacia karroo, which he believes are the most southerly known for this species in Zimbabwe. Fairly extensive wood-cutting caused us to leave this site but not before finding more Cissus cactiformis. On to the next area which Andy was leading us to, further east on the road along the Nyoni Hills range. We were heading for a dam site on the Tokwe river, however it turned out that the road to the dam site was so disused so as to make it impassable. There was some compensation in the form of a field full of lovely blue flowers (Lobelia sp.) and a very healthy specimen of Euphorbia malevola as well as Cissus rotundifolia which we found was quite plentiful in the area.

It was then decided that we would go to the northern side of Nyoni Hills – the very good dirt road leading to a PTC Repeater Station at the far north-eastern side of Nyoni Hills where the last Tree Society visit took place. As we drove up the road climbing to the top of the hills we were treated to an uncommon sight in Zimbabwe these days – Brachystegia glaucescens forest which looked as if most of the trees had never been subjected to cutting. On the way up we were again treated to aloes in bloom – Aloe excelsa, Aloe aculeata and a few Aloe parvibracteata. On the way down later in the evening we stopped at the most magnificent colony of Aloe cryptopoda I have ever seen, many of the plants having three and even four tall simultaneous inflorescences growing in the company of some tall Androstachys. Having reached the end of the road we made a lunch stop and then split up, some of us exploring at the end of the road and the others walking along the road leading back the way we had come. The first group managed to find only one small example of Calantica jalbertii (Bivinia jalbertii).

Cassipourea congoensis. Photo: Mark Hyde. Source: Flora of Zimbabwe

A fair number of Androstachys trees were seen some of them looking really ancient. A goodly number of other trees were seen at this site including Coddia rudis, Olax dissitiflora, Trema orientalis, Lagynias dryadum, Tabernaemontana elegans, Cassipourea congoensis and the not often seen Monanthotaxis chasei recorded from our previous visit. The second group had explored further down the road and there managed to locate two regrown specimens of Calantica. We only managed to scratch the surface here, and it would certainly be worth a longer visit in the future. Our second last stop was at the PTC Repeater Station situated near the top of the far end of the hills overlooking the Tokwe River Gorge, which we had teed to reach from below in the morning. This spot gave a magnificent view down into the gorge where we could just make out the river below. (Talking of rivers, many of the rivers that we passed over in this part of Zimbabwe still had water in them unlike most rivers in Matabeleland). This was the first place we had seen epiphytic orchids on/in the trees apart from the widespread Ansellia, obviously receiving moisture-laden mist and winds blowing up from the lowveld/Indian Ocean. Aloe cryptopoda was seen again here also in flower in the company of Strophanthus kombe just sending out a strong new shoot, and some more plants of Cissus rotundifolia. This river gorge would certainly be worth visiting again. It was now beginning to get late so we started back for Masvingo, the last stop being at the lovely Aloe cryptopoda colony. As we were feeling a bit tired we decided to stop for dinner at the restaurant at Riley’s Truck Stop before continuing on to the guest house.

Grateful thanks to Andy MacNaughtan for arranging this part of the long weekend for us.

-Anthon Ellert

 

BUCHWA – 12 AUGUST 1996

In search of Oreobambos buchwaldii.
After our last trip to Buchwa, wonderfully described by Tessa in Tree Life No 182, the Buchwa bamboo preyed on Anthon’s mind and so some eighteen months later we found ourselves back on the mountain. In another issue of Tree Life, Pat Bellingan described Buchwa as a distant blue ship surrounded by legends including one of a lake on the peak containing ‘hairy’ fish’. The possibility of a lake now exists as mining is to cease in the near future. The pumps which continually drain the enormous crater and the machines extracting the iron will fall silent leaving the mountain to start the long process of healing itself from the scars of badly planned mining. Unfortunately, the overburden from the opencast mining has, on a number of occasions during the rains, slipped down the hillside in great waves of mud and rock obliterating everything in its path including the main bamboo colony. Some very large cracks around the edge of the pit probably mean another slip is likely during the next rains.

The Buchwa Range consists of various peaks, with the northerly point, where the mine club is situated, called Hwikwi, two shallow peaks with a ridge between them is called Manyanga (the first geologists called it Bicycle due to its shape) and the highest point being Buchwa to the southwest. On a geological note this is a most interesting area as the flat dry country surrounding this range has a similarity of rock types to that of parts of the Great Dyke with serpentines and adjacent small chromite reserves. The mountain range covered in a green blanket of various Brachystegia consists of banded ironstone and pockets of a reddish brown coloured rock called jaspilite wherein the main source of iron ore is found, a particularly large deposit being below the Peak. Where the original exploration road (1950) cut through the crest of Buchwa the seams of banded ironstone, now colonised by lichens and mosses, twist and fold into incredible shapes like some ancient mural. Instead of using the cable access up the slope, our guide saw fit to use the long route which involved a difficult ascent up to a disused dump truck road, causing a few anxious moments while spread-eagled with feet scrabbling on loose rocks. Somehow everybody made it and a little further on the second ascent waited (with its cable) leading up to the remaining piece of the old exploration road, its source having vanished in the 60’s when explosives blew the top off the mountain. Now a mixture of colonising plants such as Acacia gerrardii, Erica benguelensis and Rhus chirindensis now occupy the once flattened surface.
Scrubby Msasas facing the prevailing wind kept Werner and Virginia on the go with epiphytes galore while we absorbed the scenery, incredibly green for the end of winter and noted the typically Eastern Districts vegetation. This including the ubiquitous Guava – Psidium guajava first recorded here in 1973, the result of a geologist’s lunch perhaps!, to Halleria lucida (subject of an article some months ago) with delicate orange blooms, blankets of yellow flowering Aeschynomene sp. in the damp streambeds. Brachylaena rotundata displaying the white waxy underside of its leaves when hassled by gusts of wind, the attractive Heteropyxis dehniae with pale trunk and wonderfully aromatic leaves, and Solanum renschii with curious fruits, pale and inflated. From the end of the road and along the crest the vegetation becomes almost mono-specific, partly due to the banded ironstone seams close to the surface, with Msasas and Faurea saligna, the majority being somewhat stunted due to the shallow soil. An attractive little Plectranthus sp. grows up here on exposed areas forming a grey carpet where droughts and falling branches have opened up the woodland canopy. In deeper soils the trees are larger but gnarled and twisted and in moss covered branches Aloe arborescens adopted a different guise, quite a number had developed true arboreal habits growing in and from forks in tree branches with epiphytes tucked into the roots! The woodland thins close to the main stream trickling off the mountain, the rock having a very shallow layer of soil opening a causeway which closes again as the gradient eases with some large trees including Bridelia micrantha, a lovely glossy green Oxyanthus speciosus, a thicket of Bequaertiodendron and a few tree ferns Cyathea dregei. Here clear cool water gurgles and invites you to a drink or two, but not much more as the algae disperses easily. A solitary white-necked raven, curious about our movements flew lazily overhead and disappeared, very soon reappearing with 30 others to do battle with a pair of pale brown coloured raptors who made a sudden landing in a newly bronzed Msasa on the crest. Hidden by a tangle of the glossy green Diospyros whyteana, Kenneth and I explored a deep, low roofed cave full of damp crevices and the odour of last night’s fire strong in the air. Probably stopping points for a herdsman as cattle are often grazed on the mountain in the dry months. The folds and twists in the banded ironstone here are dramatic forming a huge curved amphitheatre over which the stream trickles down into a pool below. The sides of the stream are really too steep to climb down safely but with some careful manoeuvring on overhanging rocks the banks become visible with Nuxia congesta covered in small, white, sweet scented flowers, more Bequaertiodendron, Maesa lanceolata, Syzygium guineense, lots more flowering Halleria lucida and Ilex mitis clustered about the water’s edge.
Still keen to find the bamboo, a smaller stream on the return trip looked promising, if only to have a glimpse of the plant in question. Here the gradient is very steep, to a stream which runs over a vertical rock face some 100 metres above the tree line on the lower slopes. Down here while recovering from the exertion, we looked up at the enormous Uapaca kirkiana which overhang the shallow basin of rocks with Albizia adianthifolia (very Eastern Districts) and Albizia versicolor. On the cattle trail Protea petiolaris appeared and in the ravine below, just above the blanket of Brachystegia glaucescens a solitary Phoenix reclinata. Gasping our way back up the slope on wobbly legs, slipping often on the dry sedges, Jonathan while catching his breath found a very attractive blue coloured Streptocarpus sp. in a wet rock crevice. Higher up the slope in the wet soaks the pinky-white lobes of the insectivorous Drosera sp. lay flat waiting for a fly or similar prey to visit and on the breeze the sweet scent wafted past from the mass of white flowers of a Sericanthe. Each time we sat down for a breather the flock of ravens circled overhead, an ominous sign we thought. While we were absorbed in watching them Kenneth tricked a snake (some reticulated job) into a bottle (with the assistance of the guide Alec) to compensate for the loss of a scorpion (found worse for wear later in the backpack). Just a few minutes later at the cable a reunion with the others and time to exchange notes and wave specimens around. Alas Oreobambos buchwaldii eluded us once again.

More recently Tom Muller said that he felt we were too far along so perhaps 3rd time lucky, what about it Anthon?, and many thanks for organising another most enjoyable trip to Buchwa.

-A. MacNaughtan

 

BUCHWA REPORT ON THE ORCHIDS

The visit to the Buchwa Mountains was very fruitful for those members with a special interest in orchids. So far the Rhodesian Schools Exploration Society report of 1973 has reported one terrestrial orchid typical to the Eastern Highlands, three epiphytic species typical to the Highveld and four epiphytic species typical to the Eastern Highlands. All these epiphytic orchid species were found. However, interest focused on the Eastern Highlands species and the state of their habitats. It was surprising and pleasing to see most of these growing in abundance on the higher, steep slopes and the top of the ridge, very often forming big clumps on the bigger branches of Msasa trees.

Three additional epiphytic species were found, namely Stolzia repens and Polystachya zambesiaca (?) which are both characteristic to the Eastern Highlands but do not represent new recordings from the southern division of the country. A third plant which was found in abundance has not been identified so far. We hope it will flower in cultivation to reveal its identity.

-Werner & Virginia Fibeck

OOPS
The small white flowered shrub seen on our July trip to the Great Dyke and noted as a coloniser of damaged areas was not Scabiosa sp. but rather two of the Sutera species.
Firstly the plant colonising the almost pure serpentine is in fact Sutera fodina and is distinguished from Sutera burkeana by its larger flower which has a yellow throat and white corolla, the latter having a brown throat and smaller leaves. Sutera fodina is an endemic Dyke species and has larger leaves and flowers compared to its more common relative.

 

VISITORS TO A FLOWERING EUPHORBIA MATABELENSIS, A STUDY IN INSECT PREY AND PREDATION

Sunday 16 May 1996 in the Raffingora area.

Euphorbia matabelensis. Photo: Bart Wursten. Source: Flora of Zimbabwe

A spectacular feature was a Euphorbia matabelensis in full flower. It was in characteristic habitat growing out from a granite dome, in a soil packed crevice in the rock. The three-forked Euphorbia blended in a grey pink with the rock but what was the striking contrast was the blaze of yellow flowers on the leafless branches.

The flowers in themselves were fascinating, each flower was an inflorescence which was small and round, about the size of a ten cent piece and borne on short spike-like shoots. The inflorescences were in dense heads consisting of up to five cyathia.

The cyathia is a fleshy flower-like structure which consists of an involucre with a ring of glands or nectaries at the rim.

An involucre is made of a gland platform subtending a very dense flower head. The cyathium is peculiar to the genus Euphorbia and is a single involucre with stamens and a stalked ovary. The ovary develops into a three part capsule.
The involucre is yellow and saucer or bowl shaped and was serving exactly that purpose.
Numerous flies were lapping like kittens from the yellow saucers full of nectar.
Flies are insects having six legs and a body divided into three segments, head, thorax and abdomen. Flies belong to the order Diptera which means two wings. The second pair of wings is modified to tiny drum stick organs called halteres. The halteres are flight stabilisers and flies are superb aviators. Flies fly very efficiently.
The soft tongue-like mouthparts are known as the proboscis. There are two pads at the end of the proboscis which contain numerous grooves or pseudotracheae up which liquid is forced into a central channel. The lapping is the lifting and extending of the flat tongue-like proboscis causing the nectar to be driven into the pseudotracheae and actively pumped by the powerful head muscles into the gut.

The smell from the flowers was honey but musty, reminiscent of a heady mead.

The bright yellow flowers and scent plus the warmth radiating from the rock made the site an entomological paradise. Insects are cold-blooded and become moribund when their bodies get too cold.

The lapping flies were mainly from the family MUSCIDAE which are medium sized flies resembling the house fly. The family is so common that most of the flies in the group are referred to as muscoid flies. The house fly is distinguished by four stripes on the thorax.

The male is distinguishable because the eyes are much larger than those of the female and meet on top of the head.
The blue bottles belong to this group and several were observed with their beautiful blue metallic colouration. One had fallen prey to a robber fly belonging to the family ASILIDAE. These flies are bristly, and have a bearded face and horny proboscis adapted for piercing. The long prehensile legs are hairy and resemble those of a dragon fly (which is not a fly). They are used as a trap to scoop up insects on the wing. There were two different genera of Asilids present.
It was surprising to see a small brightly coloured green, black and orange body fruit fly with spotted wings. Fruit would not be forming for some time and the milky fruit of the Euphorbia would not have been attracted to the larva of the Mediterranean fruit fly and the adult had probably been attracted to the nectar. The give away to identification was the way in which it moved its wings up and down whilst resting. The fruit fly belongs to the family TEPHRITIDAE. It should not be confused with the little DROSHPILA, or vinegar flies commonly referred to as fruit flies. These are the laboratory flies used in genetic breeding experiments. Other attractive little flies were the metallic coloured soldier flies that had their wings folded like scissors and marched up and down the fleshy branches with military precision. When the branch was tapped with my pen or they were aware of my presence they took refuge out of sight on the other side of the branch. To the uninitiated it resembled a bee with a furry yellow and black body. It poised in mid air hovering and was as the name suggests a hover fly. These flies are deceptively bee-like and excellent fliers. The proboscis is soft and fleshy. There were no bees present, probably because of the lack of pollen, the musty smell of the nectar and open structures of the flower.

Pollination of Euphorbia matabelensis is by flies.

There were no butterflies and the cup shaped involucre may not have been so convenient for an insect with a long proboscis. The only evidence of butterflies was a small geometrid caterpillar looping its way along a branch. Once disturbed it extended itself out stiffly only holding on with its basal claspers. The colour was greyish pink and it looked exactly like a tiny branchlet in its frozen position.

An observation suggesting long proboscis was not suitable was the absence of the small bumble bee flies who feed in flight using a long proboscis. These endearing little flies belong to the family BOMBYLIDAE.
Two further predators were very conspicuous and these were Assassin bugs belonging to the true bugs, HEMIPTERA, or half-winged, because the basal part of the wing is thick and leathery and unfolds into a membranous outer part. The Assassin bugs belong to the family REDUVIIDAE, and have a three-segmented beak which fits into a groove on the ventral side of the thorax. These bugs lunge and stab with their beaks which are armed with four sharp lancets to skewer their prey. They suck the body fluids from their pinioned prey. The hollow remains of their victims are discarded. One large Assassin bug was sucking the juices of a large Sarcophagid fly. These are large grey flies with black stripes on the thorax and a red tip to the abdomen. They are large flies who buzz when they fly. They join picnics and are a nuisance. The females are attracted to foodstuff for egg laying.
The other Assassin bug was smaller and was a marvel to behold through inverted binoculars. It was red and black and the venation of the membranous part of the wings was strewn with metallic gold drops glistening in the sunlight, a veritable snare for any nectar seeking insect. These bugs are brightly coloured and place themselves on flowers in order to lure their hapless prey.

Another interesting little predator sitting on a single spun out web was a delightful little flower spider looking exactly like a loose involucre gland platform. Spiders are not insects because they have eight legs, the body is not divided into three parts and there are no wings. Spiders belong to the class ARACHNIDAE. The little flower spiders belong to the family THOMISIDAE and are pretty, like little petals in pastel shades of pink, yellow and green. They usually grasp their unwary victims when these visit flowers, the web was not intended for trapping but may have been a support to show the spider off to full advantage. A fly coming too close would get grabbed and the spider could then traverse the silken thread and consume its quarry in relative safety.
If only time had permitted more observations. A visit at a different stage in the development of the Euphorbia would have revealed yet another population of insects etc., all deriving sustenance in some way from the plant. The secret of these studies is to watch and wait and the intricate world of inter dependencies will reveal itself

-MARY TOET.

 

ZIMBABWEAN HERBALISTS GET ORGANIZED

Prompted by the growing number of Zimbabweans resorting to traditional herbal medicine, a group of herbalists and conservation experts has set up an indigenous herbal garden on the outskirts of Bulawayo to promote and grow local medicinal plants. Traditional healers have been responsible for much destruction of medicinal plants, and among the endangered herbs are those used to treat stomach and chest complaints, high blood pressure, asthma, hookworm, infertility and mental illness.

The garden is only a first step towards a more ambitious project to set up a regional training centre for research into herbal treatment. Once the centre is built, plans include joint scientific studies with universities in southern Africa, and the compilation of a directory of herbal plants in English, Shona and Ndebele. Herbalism is the oldest form of medicine, and some 80% of Zimbabweans have faith in it. There are 40 000 members of the Zimbabwean Traditional Healers’ Association and more than 500 plants are used medicinally in this country.

 

HIPPOCRATEA in Zimbabwe

At the last Botanic Garden Walk it was suggested that in October we should look at the genus Hippocratea. Ten species occur in Zimbabwe and, in preparation for the walk; these have been listed below, together with the Flora Zambesiaca divisions in which they have been recorded.

The genus Hippocratea has also been fragmented into six different genera and these names are shown in the list, together with the former name in Hippocratea.

ELACHYPTERA A. C. Sm.
1. Elachyptera parvifolia (Oliv.) N. Halle NWS (Hippocratea parvifolia Oliv.)

REISSANTIA N. Halle
1 Reissantia indica (Willd.) N. Halle NWCES (Hippocratea indica Willd.)
2. Reissantia parviflora (N.E. Br.) N. Halle NW (Hippocratea parviflora N.E. Br.)
3. Reissantia buchananii (Loes.) N. Halle NWES

APODOSTIGMA R. Wilczek
1. Apodostigma pallens (Oliv.) R. Wilczek E (Hippocratea pallens Oliv.)

PRISTIMERA Miers
1. Pristimera andongensis (Oliv.) N. Halle var. volkensii (Loes.) N. Halle & B. Mathew NE (Hippocratea volkensii Loes.)
2. Pristimera longipetiolata (Oliv.) N. Halle NWCES (Hippocratea longipetiolata Oliv.)

SIMIRESTIS N. Halle
1. Simirestis goetzei (Loes.) Wilczek E (Hippocratea goetzei Loes.)

LOESENERIELLA A. C. Sm.
1. Loeseneriella africana (Willd.) N. Halle NWES var. richardiana (Cambess.) N. Halle
(Hippocratea africana (Willd.) Loes. var. richardiana (Cambess.) N.K.B. Robson)
2. Loeseneriella crenata (Klotzsch) N. Halle NES (Hippocratea crenata Klotzsch) K. Schum.)

In addition to the ten species listed here, there is a reference to a Hippocratea sp. no.1. It was recorded (Muller 2361) from the Eastern Division in Bob Drummond’s 1975 Woody check list. The current status of this species is not known to me.

-MARK HYDE.

 

FORESTRY WASTE FIGHTS CHOLESTEROL
A new margarine from Finland, using forestry waste as its secret ingredient, is causing logjams at supermarkets because it is said to reduce blood cholesterol by as much as 14%.
The margarine’s active ingredient is plant sterol, a compound actively washed away by pulp-mills. Plant sterol has been known for some time to reduce cholesterol levels, but the margarine manufacturer has patented a process to make it soluble in fat. The little company has been inundated with calls from bankers and brokers all hoping to get their slice of the action.

FIRST HEMP RESEARCH PROJECT IN SOUTH AFRICA
South Africa’s first legal dagga plot – an experimental project near Rustenburg in the Northwest Province –has completed pioneering research that could provide farmers with a lucrative new cash crop. The Tobacco and Cotton Research Institute is researching a model for industrial hemp that has over 500 uses, and is especially useful for making good-quality paper, textiles and building materials. There are said to be many constructive uses for Cannabis, and emerging farmers will easily be able to grow it as a viable cash crop. The plant is suited to South African conditions and does not require fertilizers and pesticides.
Industrial hemp contains only 0.4% of the drug THC (the stuff that makes you high), while the powerful dagga plants that are used as a drug has a THC content of 6-10%.

 

ANDY MACNAUGHTAN CHAIRMAN