PlantLife Volume 59.8, July 2025. A bioblitz for high-altitude plant species at Ngele

 

A CREW bioblitz for high-altitude target plant species at Ngele

by Graham Grieve, Alison Young and Ruth Cozien

All photographs were contributed by members of the bioblitz team

 

The Ngele mountain range in KwaZulu-Natal hosts a large area of Afro-temperate Forest and its lower slopes are mainly covered with commercial forestry. Generous firebreaks consisting of unmodified Drakensberg Foothills Moist Grassland separate the plantations and many hilltops have been left untouched. The main area of botanical interest however, is the Ngele Nature Reserve. The commercial forestry activities stop roughly at a 1500 masl contour and from there up to the peak of Ngele mountain at 2270 masl there is a glorious swathe of pristine grassland, stretching from the provincial border with the Eastern Cape in the west up to the saddle through which the N2 highway passes on the eastern flank.

Despite increasing grazing pressure from cattle from surrounding community land, these grasslands are still home to many plant taxa of conservation concern. The majority of these were recorded previously from the high-altitude areas along the ridge of the range. However, many of these taxa have not been recorded in recent years and CREW decided to arrange a bioblitz in January 2025 specifically targeting these species. The list of target plant species was rather elastic (additions kept on coming even while in the field) but included the following:

• Arrowsmithia conferta
• Asclepias schlechteri
• Disa tysonii
• Emplectanthus gerrardii 
• Euphorbia gerstneriana
• Helichrysum tenax var. pallidum
• Hesperantha ingeliensis
• Satyrium microrrhynchum
• Schizoglossum singulare
• Schizoglossum elingue subsp. purpureum
• Schizochilus bulbinella

With the Ngele mountain range in the background, the Ngele bioblitz team: from l to r, Jolett Pieterse, Isabel Johnson, Ruth Cozien, James Halle, Alison Young, Roy Caister, Muhammad Adamjee, Suncana Bradley and Graham Grieve

As Graham spent several years exploring forests and grasslands in the area, his name was on the list of volunteers for this project. Drawn mainly from the Midlands and Durban CREW groups, everyone gathered at the accommodation near Kokstad on the Friday evening to plan the activities for the next two to three days. With the weather forecast in mind, it was decided to go first to the plateau near Belfast Lookout (previously a fire lookout station) and follow that with a visit to the Umsilo Hut area the next day.

In two vehicles, the group set out early on Saturday morning on the usual route to Belfast Lookout. Coming around a corner about halfway up the foothills, they were met by the sight of a substantial boulder blocking the forestry road and beyond that, a very big pine tree lay across the road. Without a large chainsaw and several hours of hard labour, there was no way past the tree. While there was probably a way around this blocked section of road, it would take some exploring to find a new route, so the decision was made to postpone the visit to Belfast and head to Umsilo instead.

The two obstacles in the way of getting to Belfast Lookout

Graham then learned how difficult it is to get two vehicles full of plant enthusiasts past interesting bits of grassland. No sooner had a vehicle stopped because someone spotted something interesting than, within seconds, all nine group members were scattered across a hillside. Since the main aim for this bioblitz was to get the group as close as possible to the upper slopes of the mountain to allow adequate time to explore the high-altitude areas, it took some effort to get them back in the vehicles. Unfortunately, the stops were repeated several times before finally reaching Umsilo.

The swarming dispersal of team members as soon as the vehicles stopped for a roadside sighting

Once there, the fitter members of the group set off towards the nearby peaks while the others botanised among grazing cattle to see what was flowering on the foothill grasslands and forested drainage lines. Having been involved in a research project on Barberetta aurea, Graham was gratified to see how well this species was doing. Almost every shaded area had a cluster of these delicate, yellow-flowered plants, even some distance from drainage lines. It was also interesting to see them flowering in late January, despite previous experience that they flowered best in December.

Barberetta aurea

From Umsilo at approximately 1400masl, the high-altitude group ascended 600m to the ridge just below 2000masl, progressing through minor botanical distractions including Syncolostemon stenophyllus, flowering profusely on the grassy slopes around 1700 masl. The plants were buzzing with the activity of honeybees, Amegilla and Nemestrinid flies, including what turned out to be an undescribed species of Prosoeca. Ruth had to tear herself away from the pollinators to focus on the goal of attaining the mountain ridge where it was hoped the target species would be found. Being by far the fittest, Ruth continued up the last 100 m to the high ground from where she could see over Pakkies Farm towards Kokstad. On this ridge, a small pink flowered Hesperantha grew in rock niches and on the edges of rocky flats – this was not the target H. ingeliensis (Rare) but rather H. glareosa, with narrower leaves and more flowers. Also, among the rocks, growing in wet crevices, she found Hesperantha alborosea, not on the target list but Rare, having been previously collected at Ngele in 1989 and otherwise known only from two other sites in the Drakensberg. A few hundred meters further she found the first of a few patches of the diminutive but unmissable Schizochilus bulbinella (Rare), growing in colonies in damp flattish ground on the ridge, in the company of Euphorbia clavaroides.  The Schizochilus checked off at least one target species for the day, which was lucky as by then the ridge was enveloped in dense cloud and Ruth was having to rely on her GPS to get to the rendezvous with a vehicle.

Once most of the group had gathered back at the vehicles, it was decided to return via a different route to find a way around the Belfast road blockage. Graham’s local knowledge enabled them to navigate almost to a road junction above the blockage, only to be halted by a minor landslide that had tipped two small trees over the road. After squeezing past the new obstacle and continuing to the entrance to the plantations, hearts sank on finding another large boulder in the middle of the road but fortunately they managed to negotiate a way around it and return to the Ngele lodge. At that stage, mistbound Ruth was navigating by GPS along the skyline towards the saddle where the N2 crosses the Ngele range. Fortunately her progress could be monitored with WhatsApp pin drops and by expanding the digital map the group could find her at the point where her descent met the road.

A fortunately unnecessary attempt to move this boulder as we were able to edge the vehicles around it.

Early the next morning, the group followed the new route to the Belfast plateau. After deciding on a route for the high-altitude group to attempt, that left much of the day for the rest of the group to explore the rich biodiversity of the grasslands and rock outcrops.

From the Belfast lookout at 1600 masl, the high-altitude group headed up a series of ridges and plateaus, aiming for Ngele Peak that featured in several locality descriptions for target species. In the first cliff band, emerging onto the shoulder of grassy flats they found Pachycarpus grandiflorus (being visited by wasps), Eucomis autumnalis, and the sweet smelling Satyrium parviflorum, as well as colonies of S. longicauda (at least four distinct forms encountered on this trip). 

Pachycarpus grandiflorus

Schizochilus bulbinella

On wet rock sheets there were colonies of hundreds of Schizochilus bulbinella, a good 5 km from the populations seen the previous day. They found several more patches, confirming good sized subpopulations distributed across the area. Also in these damp areas there were hundreds of yet another beautiful decoy Hesperantha, this time the well named water loving H. hygrophila. Further up, fields of fuschia inflorescences of the short Watsonia gladioloides decorated a grassy hilltop and Schizochilus flexuosus grew along seeps on exposed rock flats. From here the contour path looked ideal for another target species, Disa tysonii, but it was not found, although many other of the more common orchid species were present (Disa versicolor, D. brevicornis, Habenaria laevigata, Pterygodium sp., Disperis cardiophora, Satyrium trinerve, Eulophia hians and E. zeyheri). Focussing on the target list, Ruth headed up to the rocky ridges again and at about 1800m, encountered Arrowsmithia conferta in exactly the predicted habitat, plentiful among boulders on outcrops. Other colourful highlights included the deceptive Disa pulchra, with a visit from a tabanid fly fooled by its similarity to pink Watsonias, more fiery-red Cyrtanthus, Diascia anastrepta with its oil-bearing spurs at right angles to the flowers, and very long tubed drumsticks, Zaluzianskya microsiphon. On reaching the mast at just above 2260m, a descent route was plotted to include as many rocky outcrops as possible, still hoping to spot Phylica tysonii (again, no luck). Stopping in the shade of a large boulder to refuel, Ruth spotted the small purplish flowers of a milkweed with promising red stripes on the sepals. A quick check with a hand lens and comparison with the information sheets suggested this could be the target Schizoglossum singulare! She hunted through similar shady grass patches next to boulders as she moved downhill but found only a few more plants and no longer in flower. The next day the identifications of A. conferta (VU) and S. singulare (VU) were confirmed at the laboratory with a microscope and the support of someone with greater knowledge of terminology and floral parts.

Arrowsmithia conferta

Arrowsmithia conferta habitat

Schizoglossum singulare

By the Monday, Graham had left the group with rough directions on how to get to the forest surrounding the source of the Mtamvuna River. However, while heading there, they were thoroughly distracted by the plant life foreign to their home hunting grounds. First, there was a magnificent swathe of Agapanthus campanulatus on a large bank of a plantation track. Next, a deep shady bank with Streptocarpus necessitated a stop – it proved to be S. johannis, a new addition to our growing list of streps. Then there was another minor stop further on for Thunbergia purpurata, a rather surprising find since it appears to be a sub-tropical or coastal species. Finally, they arrived at the Mtamvuna River (a small stream at this point), parked the vehicle in the shade and walked into the forest. The vegetation under the forest trees was sparse and showed signs of cattle visits so the decision was made to try another entrance to the forest instead. This was much more promising, when, from the start they had to fight their way through dense vegetation. Large fallen Podocarpus trees may have prevented cattle moving further in but didn’t stop the group. Orchids apparently love rotting Podocarpus bark.

Not far in Calanthe sylvatica were found in the leaf litter on the forest floor and on rotting Podocarpus stems. The group noticed that two other plants in the immediate vicinity had the same colour flowers, Isoglossa cooperi (Acanthaceae) and Impatiens hochstetteri (Balsaminaceae), and wondered if they shared the same pollinators. The forest floor opened out, probably not because of cattle grazing but more likely because it was too dark. At a point along the river clear of fallen trees and boulders, they finally stumbled on the main plant on the target list in this forest habitat, Emplectanthus gerrardii (Apocynaceae). There were several small plants but only two had flowers and one even had the distinctive paired fruits.

Calanthe sylvatica

Emplectanthus dalzellii

Finally, it was decided to make one last visit to the top forest above the eastern side of the N2 highway. This involved a short walk on a well-used tourist path where a Green Water snake basked in a small patch of sunlight on the path. This was followed by a precarious sprint across the N2 into the forest margin where the first encounter was another unfamiliar Apocynaceae, Cynanchum ethiopicum. The well-kept but rather muddy path took them past swathes of Begonia geranioides and B. sutherlandii and more species of Streptocarpus, including S. bolusii and S. rexii. Emerging out of the forest at the top into a grassland they found Dioscorea brownii, with both male and female plants in flower. The timing for catching these in flower was perfect.

Dioscorea brownii

By this time the entire day had been spent shooting plants with our various cameras and it was getting quite late, so it was decided not to do the planned round trip but rather to head back down the same way as a quicker route to the carpark.

Summary of the observations posted on iNaturalist from this bioblitz

 

The group ended up finding only four of the original target plant species. However, there were observations posted of other Taxa of Conservation Concern, namely: 

• Dioscorea brownii (Endangered)
• Hesperantha alborosea (Rare)
• Senecio poseideonis (Rare)

All in all, this turned out be a most enjoyable trip for all participants. However, it was decided that a repeat visit slightly earlier in the flowering season would be justified, as it could be a better time for finding the remaining target species.