Eight new plant locality records for Eswatini from Malolotja Nature Reserve
L Loffler, 24 June 2021
Malolotja Nature Reserve (MNR) is one of the finest and impressive treasure troves of flora and fauna in southern Africa. The mountain scenery is spectacular and the unspoilt wilderness is highly restricted outside of its borders within Eswatini. The Reserve covers some 18 000 ha, ranging in elevation from the Ngwenya Mountains at 1830 m.a.s.l. down to the Nkomati River at 640 m.a.s.l. Habitats change from montane grassland and mist belt forests in the higher areas down to riverine scrub and bushveld in the river valleys.
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| Northern Malolotja Nature Reserve (MNR) |
The geology in the reserve is complex and forms part of the "archaean basement" of what has later become the African continent. Lochiel Granite is the dominant rock type found near the main entrance gate but the remaining three-quarters of the reserve consist of even older rocks of the Swaziland Supergroup that are found in the Malolotja Valley, Ngwenya and high ground to the west. The latter are amongst the oldest metamorphosed sedimentary rocks in the world, dating back to some 3.5 million years ago.
The reserve is located within the Barberton Centre of Endemism, a sub-centre of the Drakensberg Afromontane Regional System recognised by the World Wide Fund for Nature (WWF) and World Conservation Union (IUCN) as a Centre of Plant Diversity and Endemism of global significance. The majority of Eswatini plant endemics that have been recorded in the country have been found to enjoy the exposed granite rocks in areas including Mbabane, Pine Valley and the Mdzimba mountains or on the quartzites in the southwest of the country. To date seven species have been recorded on the ancient Greenstone belt of the northwest, most from MNR, including Disa intermedia, Kniphofia umbrina, Cineraria ngwenyensis, Syncolostemon comptonii, Crassula alba var. pallida, Eragrostis comptonii and Ocimum motjaneanum. A revision of the Eswatini Flora Red Data lists and endemics is currently underway so these numbers could change.
Botanically, 2019 and 2020 proved fruitful years and eight new plant species previously unrecorded for the country were noted in Malolotja alone during hikes with Paul Loffler. In April 2019, a hike down to the upper pothole of the Mahulungwane Falls provided the first of these sightings, being Ochna confusa (Grassveld Plane). This small shrub is easily confused with other Ochna species (as the name ‘confusa’ suggests) that are more common and better known, such as its relative Ochna natalitia (Mickey-mouse bush). Its tapering leaf base, forward curving secondary veins and anthers with pores that open longitudinally separate it from its commoner relative. After seeing this plant on the Mpumalanga side of the Barberton Mountains, it was exciting to confirm its occurrence in Eswatini thus extending its range south and eastwards.
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| Ochna confusa flower and fruit. (Photos: J Burrows) |
Most hikes in
the reserve are challenging as the mountainsides are steep but the interesting plants
and geology make up for the blood, sweat and tears. To access the potholes one traverses
from granite outcrops at the Komati viewpoint followed by different rock types including
dolerite, quartzite, micaceous quartz schists, banded ironstone and conglomerates.
At the valley bottom the Malolotja river has, over the millennia, incised its
way through the underlying rock before it exits into the much larger Komati
River that makes for some awe-inspiring and dramatic scenery.
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| Above the upper pothole at Mahukungwane Falls, MNR |
Close to some old stone circles (rock walls) believed to have been constructed to keep livestock in at night by the Bokoni people (B. Forrester pers. comm.) we found a new record of Gladiolus for the country. Identified as G. vernus, it has previously been recorded in rocky grassland in the Blyde River Canyon area in Mpumalanga and in the Drakensberg escarpment. It is apparently a scarce plant in South Africa and it is fortuitous to find it flowering in July and August (vernus is a derivative of spring) in completely dry conditions before the first rain starts.
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| Gladiolus vernus, upper pothole at Mahulungwane Falls, MNR |
On the same rocky outcrop, a species of Euphorbia which is still to be confirmed and fully described, resembling Euphorbia species A (Malalane Euphorbia in Schmidt et al. 2007) was noted and photographed. This species has been recorded as having a restricted distribution, endemic to the Moodies geological formation between Malalane and Barberton, including Lows Creek (and now possibly includes Eswatini). The continuous spine shields and somewhat stunted appearance are notable characteristics but more research is required to separate it from the E. grandidens complex, if it is indeed different.
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| Euphorbia sp. A (to be confirmed) upper pothole Mahulungwane Falls, MNR (Flower photo: R Boycott) |
Malolotja has scenic views that are hard to match and one such viewpoint is worth every inch of hiking effort. A short drive from the entrance gate moving west towards the Logwaja viewpoint leads you to the idyllic crystal clear ‘infinity pool’ which is actually the top of the very scenic Malolotja falls.
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| Infinity pool, MNR |
En route to this hidden gem we found Olinia rochetiana (Rock Hard-pear) which is a small tree up to 4 m tall, often associated with rocky outcrops and quartzitic soils. It has previously been documented as an endemic to Mpumalanga and the Limpopo province but its distribution can now be extended southwards to include Eswatini. Its square branchlets are evident and the distinctly sunken secondary veins on the leaves which turn red in autumn separates it from the more widespread O. emarginata (Mountain Hard-pear).
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| Olinia rochetiana leaves and bark, MNR |
Pavetta eylesii (Flaky-bark Brides-bush) was recorded on the same walk. It has distinctive thinly textured and finely hairy elliptic leaves with obscure tertiary veins below. Even though recorded from Zimbabwe, Botswana and northern provinces of SA, it is apparently a rare tree in neighboring Mpumalanga and is uncommon in Eswatini which is a more southerly locality. It was previously thought to have occurred in the south-west of Eswatini as per the Swaziland Tree Atlas (P. & L. Loffler, 2005) but new debate about it has taken place since then putting that finding on hold for now.
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| Pavetta eylesii flowers and bark (Source: Flora of Zimbabwe) |
Much later in mid-November 2020 Paul and I hiked into some of the remote parts of the Komati River valley. The lack of paths and abundant foliage indicated that not many humans frequent the area (not even Cannabis farmers). On this outing we stumbled across the scrambling shrub, Combretum tenuipes, formerly referred to as C. padoides (Thicket Bushwillow) which is usually found at the edges of riverine thickets and on rocky hillsides. Having seen it in the Barberton Mountains in South Africa we knew it should be in Eswatini but hadn’t banked on having to scramble for an entire day to find it. The leaves are characteristically wavy and arch up on either side of the midrib, there are small silvery scales visible to the naked eye and the twigs are not spine tipped.
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| Combretum tenuipes, Komati River, MNR |
Venturing further north closer to the historic asbestos mining town of Bulembu, flowering plants are in abundance. In November 2020 the seventh new record photographed, growing on black reef quartzite outcrops, was the herbaceous perennial Syncolostemon teucriifolius (Teucrium-leaved Sagebush). This bushy shrub with a woody rootstock has been recorded in the Eastern Cape, KwaZulu-Natal, along the Drakensberg Mountains to Mpumalanga at elevations ranging from 700 to over 2000 m. It then seems to do a big jump in its distribution northwards up to Zimbabwe. Distribution records have shown a gap from near Durban with it popping up in the Barberton area and Nelspruit with no records in between. This recording from Malolotja North along with one from adjacent Songimvelo Reserve bridge the gap slightly but the plants differ from the population found around Lydenburg, which has a long straight corolla instead of the shorter curved one, suggesting it might be a different species (Kevin Balkwell pers. comm.).
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| Syncolostemon teucriifolius, MNR |
Last but not least, in the northern section of the reserve close to the South African border, a possible undescribed species of Indigofera was collected. Knowing that the Barberton Centre has so many specials I consulted Dr Brian Schrire who is based in the UK for his expert opinion. Found on Black reef quartzite in Protea roupelliae and P. caffra dominated wooded grassland, he noted that the shortly-peduncled axillary flowers are distinct and most closely allied to I. buchananii and I. rubroglandulosa but that it was indeed something he has not come across before. Flowering was nearly over at the beginning of December so future collection trips will need to be conducted in the spring to determine if it is another potential Barberton endemic or at the very least a species with a restricted distribution.
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| Indigofera sp., Malolotja north, flower, habitat and whole plant, MNR |
With 18 000 hectares to cover in the reserve and the multiple pristine habitats, we are certain that this park will not let us down in finding more exciting plant records in the near future. We encourage the Eswatini National Trust Commission (ENTC) who is currently managing the reserve to continue to protect the diverse flora and fauna and allow future generations to enjoy it as much as we do.
References
Loffler, L. & Loffler, P., (2005), Swaziland tree atlas—including shrubs and climbers, 2nd edition, South African Botanical Diversity Network Report No. 35, SABONET, Pretoria.
Schmidt, E., Lötter, M. & McLelland, W., (2007), Trees and shrubs of Mpumalanga and the Kruger National Park, Jacana, Houghton, Johannesburg, South Africa.
About the Author: Linda Loffler is a self-employed vegetation consultant based in Eswatini. She has been involved with biodiversity conservation in the country for over 23 years, working with both the private and government sectors. She co-wrote the Swaziland Tree Atlas, which was published by SABONET in 2005 and has continued collecting plant data for the country since. Her passion for the eastern summer rainfall flora and their conservation has enabled Linda to explore many remote areas within the country and neighbouring South Africa and Mozambique.
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