November and December 2011

There are few mountains in South Africa richer in changing colours during the course of the day than the colossal mountain buttresses and their foothills at the western end of the Waterberg. These photograph were taken in the blue of the early evening shortly after sunset on 21 December 2011. This sort of countryside and these light conditions inspired the famous South African landscape artist, Pierneef.

SUMMARY.
Research is currently in its latter phase for a book on habitat changes conducted mostly in all the provinces of South Africa. The emphasis in the book will be on how various changes to habitats have affected mostly bulbous, caudiciform and succulent flora. The study focuses on habitat destruction such as that caused by agriculture, exotic timber plantations and mining as well as processes in the habitats themselves. The latter involves various uses of land in its existing form, such as grazing by livestock and the re-introduction of various indigenous browsing and grazing animals.

Road reserves play a significant role during changes to the countryside by preserving narrow strips of habitat between the roads and adjacent farmland. Many plants thrive in these places freed from the habitat destruction or processes taking place in existing farmland.

Certain plants are able to withstand considerable alterations to their habitats while others decline sharply to the point where they become locally extinct. Habitat changes are dynamic and beneficial for some species. Nearly all these changes are induced by different types of land use, put into place to serve the economic and recreational uses of the human dominated countryside. Habitat destruction is, in contrast, mostly an irreversible process unless agricultural lands are allowed to revert to their former state of bushveld or grassveld.

A number of bulbous, caudiciform and succulent plants are iconic, epitomising not only the process of habitat changes but also the results. The two parts of this account focus on the subject in the eastern part of the North West Province (part one) and the north west section of Limpopo (part two).

Very little flora is formally conserved in South Africa and where it is, the plant communities that are protected are in areas set aside for the protection of fauna. An understanding of the autecology of plants under conditions of different land use is indispensable for their long term preservation.

Ledebouria viscosa growing in sandy soil along the north western boundary of the Marakele Park. The leaf surfaces are covered in sand grains and their margins highly crisped.

Ledebouria leptophylla photographed in full leaf on 23 November 2011 near Letlhabile in the North West Province. The bulbs typically grow in small groups.

Ledebouria leptophylla often grows close to Ledebouria marginata near Letlhabile.
The L. marginata are always much more plentiful, however, on account of their prolific seeding habits.

NEWSLETTER PART ONE.
LEDEBOURIA LEPTOPHYLLA IN THE NORTH WEST PROVINCE.
The form of Ledebouria leptophylla that grows in the bushveld north of Brits and Pretoria consists mostly of the distinctive examples of this plant described by Venter, with strongly twisted bluish or greyish green leaves (1993: 132, 2008: 121). The leaves of this form are virtually indistinguishable at first glance from those of Gethyllis grandiflora.

Other forms have fewer broader leaves and are quite widely recorded from various parts of northern South Africa particularly in Mpumalanga and Kwazulu Natal. Venter (1993: 132) refers to L. leptophylla with the spirally twisted leaves as the commoner form but the reverse was found during the current research. The broader leaved form was found to be much more widespread and usually numerous where found. The plants with fine spirally twisted leaves are mainly sparse and infrequent where found, occurring singly or in widely scattered small groups.

It may well be that the concept of L. leptophylla needs to be redefined and if this happens the anomalies and variations currently under this species can be better accounted for. Perhaps some of the variation can be accommodated under the concept of subspecies and in other instances we may be dealing with different entities altogether.

The broad and narrow leaved forms of L. leptophylla are often separated geographically. The broader leaved plants are usually found in short grassland in hilly or mountainous areas, frequently in mist belt escarpment regions. The finer leaved form is generally associated with arid mainly deciduous woodland. This is not always the case. In one instance plants that can currently be assigned to the broad leaved form are found growing in loamy soil in combretum woodland, only a few kilometres away from the narrow leaved form that grows in sandy soil in mixed deciduous woodland.

This photograph shows the spirally twisted leaves of Ledebouria leptophylla which resemble those of Gethyllis grandiflora.

The typical open woodland frequented by Ledebouria leptophylla near Letlhabile. The bulbs grow out in the open amongst the short grass tufts as well as beside and under shrubs.

THE FINE LEAVED FORM OF L. LEPTOPHYLLA NORTH OF BRITS AND PRETORIA.
The North West Province around Letlhabile and Maboloko north of Brits has been undergoing rapid habitat degradation for the last decade. The same is true of the rural settlements west of Hammanskraal, north of Pretoria. In this area not only have habitats become degraded but also destroyed with the expansion of rural towns. L. leptophylla has declined in both areas particularly west of Hammanskraal. It will probably become locally extinct as the pressures associated with habitat destruction and habitat degradation continue.

Near Letlhabile Ledebouria leptophylla typically grows amongst short grass tufts, but sometimes occurs in open places with gravely sand.
These plants are in direct sunlight for most of the day.

This young Ledebouria leptophylla has established itself amongst short grass tufts which are resprouting in early summer after the winter drought.
The leaves blend in with the newly emerging grass blades rendering the ledebourias cryptic when they grow in these situations.

Harpagophytum zeyheri is commonly found growing close to Ledebouria leptophylla at Letlhabile. The flowers of plants growing here are typically cream with yellow throats.

Ledebouria leptophylla often grows where there are patches of coarse gravely sand on the surface of the soil. It is probable their seeds accumulate most readily in these places which remain more moist after rainfall, creating conditions conducive to germination.

L. LEPTOPHYLLA NORTH OF PRETORIA.
Some 15 years ago L. leptophylla was well represented in deciduous Burkea africana woodland just east of the Tswaing meteorite crater (formerly known as Saltpan). They were also found, but in smaller numbers, in the adjacent combretum grassland. They were reasonably numerous in small scattered groups in an area of short grassland immediately north of the burkea and combretum veld.

The tall burkea trees have mostly been chopped down and little of the original habitat remains. There has also been an invasion of indigenous Sickle bush Dichrostachys cinerea in the places were there was open burkea woodland.

Several visits were made over the past decade to search for L. leptophylla in the places where there were formerly burkea trees. Each time fewer and fewer were found until a visit in January 2011 when none were seen at all. The ledebourias have also disappeared from the short grassland. There are several reasons for this which seem to have worked in combination. Sand was removed from the area for building purposes, leaving behind shallow pans which filled with water during the rainy season. In addition agricultural lands have been established in places where the ledebourias used to grow.

The high summer rainfall coupled with habitat disturbance over the last few years has turned what used to be short seasonally moist grassland into large seepage areas. These are too wet for the ledebourias and many bulbs have probably rotted.

A few L. leptophylla are still found in declining numbers in the combretum veld which is in the process of degradation. Building sand is removed from several places, agricultural lands are also being established and there is widespread dumping of domestic rubbish and building rubble.

An important photographic record, prior to widespread degradation of the habitat, was provided by environmental journalist Carol Knoll. She took extensive habitat photographs of the grassland locality in December 2004. Some of these were published in Veld and Flora, the journal of the Botanical Society of South Africa (Craib September 2005: 126, 128 – 129). At this time I thought that the L. leptophylla may have been an undescribed species and it is incorrectly referred to as such in the caption to the photograph on page 129.

It is interesting to see how local extinctions take place. In this case the L. leptophylla have mostly disappeared from two of the three habitat niches where they once occurred. They are steadily declining in the combretum veld and can be expected to disappear from here too as habitat degradation continues.

Ledebouria papillata grows on loamy soil in acacia woodland near Legonyane, north of Letlhabile. The presence of this species is usually a good indication that Ledebouria leptophylla will not be found in the general vicinity as it prefers sandy soil.

Ledebouria leptophylla habitat near Letlhabile photographed on 20 October 2007. Early rains had fallen which generally occur in November. As a result most bulbous and caudiciform plants were in active growth such as the Ipomoea bolusiana in the foreground of the photograph.

L. LEPTOPHYLLA NORTH OF BRITS.
The habitat around Letlhabile, north of Brits consists mostly of open deciduous woodland. The grass cover is mostly short growing on sunny well drained soil. This is the typical habitat frequented by the fine leaved form of L. leptophylla. Unlike the former locality near Tshwaing meteorite crater, which had three distinct habitat niches occupied by L. leptophylla, there is only the one around Letlhabile. The ledebourias are found growing in open grassy places exposed to direct sunlight as well as in the dappled shade of deciduous shrubs. The plants generally grow singly or in small groups thinly and widely scattered about the habitat.

The habitat is in the initial stages of degradation. Trees are being felled and some domestic refuse and building rubble dumped in the area. The numbers of L. leptophylla are much smaller here than they were near Tshwaing and probably likely to disappear more quickly as full scale habitat degradation gets under way.

The ledebourias are curiously absent from a lot of what should be ideal habitat. This is not readily explained and requires additional research.

A few kilometres to the north of Letlhabile is the settlement of Maboloko. Immediately to the west the broad leaved form of L. leptophylla used to be well represented. Much of the habitat has been destroyed by the establishment of a huge sand quarry and also the dumping of refuse and building rubble. This is a pity since these plants provided a unique opportunity to study what appears to be a form of L. leptophylla growing close to the typical fine leaved plants.

Drimiopsis burkei is often plentiful in the same habitat in which Ledebouria papillata is found.
One of the reasons for this is that the plants produce prolific seed as shown in this photograph.

Ipomoea bolusiana is widespread in open areas in the same habitat occupied by Ledebouria leptophylla near Letlhabile. An Ornithogalum species, which may be undescribed, often grows together with it in the same habitat and sometimes a possibly undescribed dipcadi species, shown in the left hand corner of the photograph.

THE GROWTH CYCLE.
The fine leaved L. leptophylla flower very early, in September and October usually well before the onset of the summer rains. Flowering and seeding takes place as the leaves begin to emerge. The leaves are fully developed by the second half of November at a time when the seeds have already been liberated into the environment.

The ledebourias in the two study areas have always produced relatively small amounts of seed, from one season to the next. The paucity of seeds is likely to explain the overall rarity of the plants in the places where they are found. Seeds germinate around the parent plants which accounts for the habit the bulbs have of occurring in small groups. Some of these consist of bulbs growing so tightly together that they give the appearance of being a single large plant.

The bulbs enter dormancy between early March and late April depending on the quality of the late summer rains. In the second half of summer the leaves are often completely eaten down by lepidopterous larvae and, if this occurs, they do not usually resprout that season. This is important to note since if the plants are ever surveyed this should be done in November when they are at their easiest to find and well before they may be eaten by caterpillars.

Drimiopsis burkei leaves are somewhat rough and sand particles cling to them when they have been splashed off the ground in heavy summer thundershowers. This plant was photographed to the north of Letlhabile on the outskirts of the rural village of Legonyane.

PROCESSES IN THE ENVIRONMENT.
Fire has been and is a regular occurrence at both localities from May to early September. Fires have the benefit of clearing moribund grasses from the environment and promoting growth and flowering of the ledebourias with the more open conditions in the veld.

The alteration of the habitats through and removal of sand, the dumping of rubble and the establishment of agricultural lands degrades the quality of fires with the result that some places escape burning altogether for several years in succession. This is exacerbated as at both localities the veld is criss-crossed with tracks which further reduces the general spread of dry season fires.

Livestock, mostly cattle and donkeys, is kept in both areas where the L. leptophylla have been studied. In general there is little effect on the plants as they occur in small groups over a wide area and quite often grow in the protection of thorny shrubs. Fine leaves are also less readily damaged by trampling than broad leaves.

Amocharis coranica is commonly associated with Ledebouria papillata north of Letlhabile and around Assen to the north west.
A. coranica is another plant that rarely grows in the same habitat as Ledebouria leptophylla.

LEDEBOURIA VISCOSA.
L. viscosa is unique in the Genus Ledebouria. It has between one and three broad dark green viscous leaves to which sand particles adhere. In general appearance these leaves look like those of Haemanthus nortieri. They may be erect or prostrate. The tapering bulb arises from an often long basal stem from which it is easily detached by burrowing animals. In such circumstances a new bulb is readily produced at the point where the old one was snapped off. Some plants are likely to be many decades old in instances where the basal stem has developed a zigzag pattern from a succession of bulbs becoming detached over the years.

Venter (1993: 79) placed L. viscosa in the Section Humerati of the Genus Ledebouria and within this group in the subsection Erectifoliae (1993: 120). He considered that the species was related to Ledebouria atrobrunnea and Ledebouria dolomiticola but did not specify reasons for this. Erect foliage is not a constant character of L. viscosa and there are probably more differences between this species and the two others at the level of general morphology and autecology than there are similarities. It is probably more realistic to accommodate L. viscosa in a section of the Genus on its own rather than to group it with other species.

L. viscosa was only known from three herbarium records at the time Venter published his revision of the Genus Ledebouria. Two records were from the farms Buffelshoek and Waterval east of Thabazimbi and the other from the sandy plains west of Kransberg, a peak at the north western end of the Waterberg. Subsequently the species was found in similar sandy countryside in the eastern part of the farm Hoopdal some ten kilometres east of the Matlabas River. This record extended the distribution of the species well north of Thabazimbi (Craib and Brown 1998: 49 – 53).

Some years later I found the species again much further north on the farm Fourieskloof close to Afguns. This is cattle ranching and game farming country close to the town of Lephalele. The plants at this locality were also growing in coarse gravely sand similar to the conditions encountered east of the Matlabas River. This extraordinary jump in the plant’s distribution suggests that it is probably not a narrow endemic round Thabazimbi as originally thought. It probably occurs sparingly over a wide area from at least Thabazimbi to Afguns and Kuipersbult.

It is clear that the species is very sparingly distributed and absent from a good deal of sandy areas that seem ideally suited to its requirements. They are such distinctive plants that they cannot be overlooked by anyone with an interest in the local flora. Farmers who may read this paper are encouraged to report records of this species when they come across it, to the herbarium at the National Biodiversity Institute in Pretoria.

Ledebouria viscosa growing amongst leaf litter and dead grass in the road reserve forming the northern boundary of the Marakele National Park. This photograph was taken on 21 December 2011 after good earlier rains had initiated leaf growth and flowering.

This group of Ledebouria viscosa has had the leaves on some of the plants partially eaten by snails. This damage is commonplace during the rainy summer months but seldom serious as the leaves, covered in sand particles, are not particularly palatable for the snails. The photograph was taken along the northern boundary of the Marakele Park.

This photograph shows the broad road reserve, the road and the north western boundary fence of the Marakele National Park, the home to thriving scattered groups of Ledebouria viscosa. The ecological processes of fire and grazing are completely removed from this artificial environment.

The road along the north western boundary of the Marakele National Park, with a group of local people and their donkey cart. The road reserve to the right borders the park. To the left it borders a game farm. This road reserve is very narrow, less than a metre wide. It has for years neither been burnt nor mowed in the dry season. The result is a proliferation of shrubs and a few grassy patches full of moribund grass. L. viscosa has almost disappeared from this reserve with the removal of fire and grazing.

HABITAT CHANGES.
There have been some significant changes to the L. viscosa habitats in the past two decades. The most important of these is the establishment of the Marakele National Park in the Waterberg and the plains which lie around the western end of this mountain range. The reserve was proclaimed in 1994 and covers an area over 50,000 hectares in effect.

Most of the farms that existed before the creation of the park were used for cattle ranching. There appear to be no published records of L. viscosa from what is now the park, except from Hoopdal. This farm is now part of its north western boundary. Marakele contains a vast amount of habitat suited to this plant and there is little doubt that it occurs protected in the park in good numbers.

A molehill adjacent to a Ledebouria viscosa plant along the boundry of the Marakele Park. These moles are thought to damage a lot of the ledebouria bulbs.

A unifoliate Ledebouria viscosa showing the dispersion of sand particles across the entire leaf blade. A stem with ripening seeds is also visable in the foreground to this photograph.

L. VISCOSA ALONG THE NORTHERN BOUNDARY OF THE PARK.
At the time the plants were initially surveyed east of Matlabas, the area was used for cattle ranching. The plants were well represented with most populations consisting of mature bulbs with very few seedlings in evidence (Craib and Brown 1998: 51). Trampling of the sandveld by cattle resulted in minimal regeneration from seed.

Unfortunately no data was collected relating to plants growing in the reserve of the road that then formed the northern boundary of the farm Hoopdal. This road is now the north western boundary of the Marakele Park. Thus I am unable to compare the modern situation with the plants in the road reserve of the park to what existed before.

Soon after the electrified fence along the boundary of the park was erected the road reserve was mechanically mowed annually during the dry season. This is at a time when the L. viscosa bulbs have already entered dormancy. During this process the sand is moved around and it was initially thought that this would damage the more shallow rooted ledebourias.

A survey of parts of the road reserve was done on 21 December 2011 after good rains had fallen in the previous weeks. The L. viscosa were found to be relatively numerous in the road reserve with a few seedling plants in the immediate vicinity of the adults. It was clear that the annual mowing of the grass had benefited the bulbs and that regeneration from seed had been optimal. The absence of grazing animals, and the trampling associated with them, meant that many of the plants had the chance to flower and set seed.

The road reserve habitat along the boundary of the park has a permanent status since it is highly unlikely that the boundary fence will ever be removed. This is unlike many other parts of South Africa where road reserve fences are regularly removed and the flora in them dwindling to the point of extinction.

The road reserve along the boundary of Marakele is clearly an artificial habitat. This is true not only at the level of processes in the environment such as grazing and fire cycles, but also in the long term preservation of the altered status of this environment.

This is a young Ledebouria viscosa photographed in the woodland near Afguns. The sand round about has been pitted by the hooves of grazing cattle and horses, but, despite this a limited amount of regeneration from seed has taken place.

This Ledebouria viscosa was photographed near Afguns in the initial stages of flowering on 21 December 2011. This is the northernmost record for the species. The sand around the plant has been disturbed by the hooves of grazing animals. The leaf shown in the left of the photograph has been partly eaten by snails and the one to the right, eaten down by grazing livestock.

THE LOCALITY NEAR AFGUNS.
This place is interesting for a number of reasons. The habitat is grazed throughout the year by cattle and horses and is bounded on the western side by old agricultural lands in the process of reverting to bushveld. There is also an area that has been cleared from the woodland over which there are power lines which run across the full length of the habitat. This strip below the power lines is periodically cleared of any saplings they may establish themselves.

The woodland at this locality is mainly deciduous and not nearly as open as that encountered east of the Matlabas River. Most of the L. viscosa grow in dappled shade throughout their summer growing season. There is also far less grass cover than there is at the other locality and many of the ledebourias are found growing amongst leaf litter rather than grass.

The livestock grazes mostly in the grassy abandoned lands that are reverting to bush and in grassy patches that occur sparingly amongst the bush. The consequence is that trampling of the bulbs, when they are in leaf, is confined mostly to areas where livestock is in transit to the few grassy places where they graze. There is favourable regeneration from seed mostly in areas where there is an absence of grass or where the plants grow under shrubs.

This Ledebouria viscosa bulb has been excavated, photographed and replanted.
The habit this species has of regenerating after damage by burrowing animals is clearly visible in this photograph.

The L. viscosa are as plentiful, relatively speaking, in shaded places, which comprises the bulk of the habitat, as they are on the grassy strip below the pylons. This supports the data from the other localities where the species is found predominantly in woodland but also in open grassy areas that are met with between places where there are shrubs and trees.

No L. viscosa were found growing in the old agricultural lands. The succession of vegetation that normally occurs on disturbed ground is probably too dense for plants to colonise these sites. It may be that, with the very specific environmental requirements that these bulbs have, they will only start to appear, if indeed they do, once the habitat has been allowed to revert to its former state.

All the L. viscosa habitat known so far is found in areas used for cattle ranching, game farms and in one instance a national park where the animals that used to occur have been introduced again. There are no communally owned herds and rural villages anywhere. It is probable that this form of land use is inimical to L. viscosa, which seems to have the lowest and slowest reproductive output amongst all the ledebouria species.

The Ledebouria viscosa habitat near Afguns. This photograph was taken at the point where the undisturbed habitat to the left merges with the old agricultural lands to the right, in the gradual process of reverting to woodland.

Old agricultural lands bordering Ledebouria viscosa habitat near Afguns south of Lephalele.
The process of reversion to bushveld is very slow and these conditions are inimical to the occurrence of L. viscosa

THE GROWTH CYCLE.
L. viscosa grows and flowers during the months of highest summer rainfall from late October until about early March. The peak flowering period is usually from November to January. Some plants in a given area flower in response to good rains and the same bulb may produce successive flower spikes over several months.

Many ledebourias in a population fail to flower in a given season of adequate rainfall and during droughts nearly all the plants produce only leaves. Flower stems are readily trampled by game and livestock reducing the chances for successful seed production even further.

The seeds produced by this species are amongst the largest in the Genus. Typically they are about 7 mm long and 5 mm wide when freshly set. They shrivel somewhat after a few days, a habit typical of all ledebouria species. Most seeds lodge in sand immediately around the parent plants. They may sometimes get washed further away in runoff after every heavy rainfall. The seed distribution pattern explains the occurrence of adult plants in the habitat growing mostly in small groups or more rarely as individual plants.

Very little is known about L. viscosa and a good deal more needs to be learnt about its distribution. It is a unique species, a curiosity in the genus whose affinities remain obscure.

The woodland habitat where Ledebouria viscosa grows near Afguns consists of open sandy areas with sparse short grass. An L. viscosa may be seen in the central foreground to this photograph. Plants in these shaded places typically produce long leaves curved outwards towards the ends.

PHOTOGRAPHING AND PAINTING L. LEPTOPHYLLA AND L. VISCOSA.
These two plants are difficult to photograph and to paint. Connall Oosterbroek’s accomplished photography captures very well the way in which both plants grow in their specialised woodland habitats. Jenny Hyde-Johnson has finely honed skills for bringing to life all the details in the niches where the two species grow. She has recently finished her habitat painting of L. leptophylla and is currently busy with one of L. viscosa. Her illustrations are informed by an extensive series of photographs which she takes on visits to the ledebourias’ habitats.

Both artist and photographer immerse themselves in their work, making a unique and special contribution to the book on habitat changes.

This painting of Ledebouria leptophylla by Jenny Hyde-Johnson for the book on habitat changes shows the typical situation in which Ledebouria leptophylla grows near Letlhabile. In the foreground is a dung beetle rolling a ball of cattle dung. These beetles were frequent in the habitat on 23 November 2011, the occasion of the field excursion.

REFERENCES AND FURTHER READING.
Charles Craib. Vanishing grasslands of eastern South Africa. Veld and Flora, September 2005: 126 – 130.
Charles Craib and Laurian Brown. Ledebouria viscosa, one of South Africa’s most striking and unusual Bulbous Plants. Herbertia 1998, Volume 53: 49 – 53
Stephanus Venter. A Revision of the Genus Ledebouria (Hyacinthaceae) in South Africa. M Sc. thesis, University of Natal, Pietermaritzburg, 1993.
S. Venter. Synopsis of the Genus Ledebouria Roth (Hyacinthaceae) in South Africa, Herbertia 2008, Volume 62: 85 – 155).

The vast plains of woodland north of Kransberg at the western extremity of the Waterberg contain a great deal of habitat potentially suited to Ledebouria viscosa. Little, if anything, is known of its occurrence here. Much of this area now lies in the Marakele Park.