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Scientific Name | Colubrina nicholsonii A.E.van Wyk & Schrire |
Higher Classification | Dicotyledons |
Family | RHAMNACEAE |
Common Names | Pondo Weeping Thorn (e) |
National Status |
Status and Criteria | Vulnerable D1 |
Assessment Date | 2022/01/13 |
Assessor(s) | L. von Staden, J.E. Victor & A.E. van Wyk |
Justification | Known from about 200 individuals in the wild, however, more subpopulations are being discovered. This species grows in secluded, inaccessible gorges and it is very likely that there are a few undiscovered subpopulations, especially in the light of significant range extensions brought about by recent discoveries of new subpopulations. We estimate that there are more than 250 mature individuals but fewer than 1 000. AOO of this habitat specialist is estimated as <20 km², and it is potentially threatened by alien plant invasion at four locations. Poor recruitment is a concern, but healthy subpopulations are presently maintained by vegetative reproduction and there is no current evidence of continuing decline. |
Distribution |
Endemism | South African endemic |
Provincial distribution | Eastern Cape, KwaZulu-Natal |
Range | Between Port St Johns and the Umtamvuna River. Isolated occurrences as far north as the uMzinto district (KwaZulu-Natal) and as far south as the Kentani district (Eastern Cape). |
Habitat and Ecology |
Major system | Terrestrial |
Major habitats | Northern Coastal Forest, Scarp Forest |
Description | Scarp forest. Climax riverine forest, close to, and usually overhanging the water, 100-400 m. |
Threats |
| C. nicholsonii occurs on stream banks deep inside scarp forests and gorges, and is unlikely to be affected by forest destruction due to the inaccessibility of the habitat (T. Abbott pers. comm.).
This sub-canopy tree appears to prefer stream banks and areas where there is light filtering through sparse areas in the forest canopy (Boon 2001), the type of light conditions that is also preferred by the most serious alien invasives of forest systems in South Africa — Chromolaena odorata (triffid weed), Lantana and Solanum mauritianum (bugweed). Alien encroachment is potentially threatening subpopulations in the Vernon Crookes Nature Reserve (Boon 2001) as well as on the banks of the Mtentu (K. van der Walt pers. obs.)
C. nicholsonii could potentially decline as a result of lack of fruit set and therefore recruitment, however, at present healthy subpopulations appear to be maintained by means of vegetative reproduction (D. Styles pers. comm.). However, if wildfire were to impact on any of the C. nicholsonii subpopulations, a subpopulation could be entirely devastated with no potential of regeneration from soil stored seed banks (Boon 2001). |
Population |
Subpopulations are generally very small, consisting of no more than 10 individuals, except on Mount Sullivan, where there is about 20-30 mature individuals (T. Abbott pers. comm.) The Daza River subpopulation consists of ± 15 plants (notes on Abbott, A. 2552, 23-3-1985, NH). Three subpopulations in Vernon Crookes have respectively 15-20, 30 and 50 mature individuals (Boon 2001, D. Styles pers. comm.).
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Population trend | Stable |
Conservation |
| Protected in the Vernon Crookes, Umtamvuna, Mkambati and Silaka Nature Reserves. |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | | Colubrina nicholsonii A.E.van Wyk & Schrire | VU D1+2 | Raimondo et al. (2009) | | Colubrina nicholsonii A.E.van Wyk & Schrire | EN | Scott-Shaw (1999) | | Colubrina nicholsonii A.E.van Wyk & Schrire | Rare | Hilton-Taylor (1996) | |
Bibliography |
Boon, R. 2001. The (re)-discovery of the Pondo Snakewood, Colubrina nicholsonii, in KwaZulu-Natal. PlantLife 25:17-19.
Boon, R. 2010. Pooley's Trees of eastern South Africa. Flora and Fauna Publications Trust, Durban.
Hilton-Taylor, C. 1996. Red data list of southern African plants. Strelitzia 4. South African National Botanical Institute, Pretoria.
Raimondo, D., von Staden, L., Foden, W., Victor, J.E., Helme, N.A., Turner, R.C., Kamundi, D.A. and Manyama, P.A. 2009. Red List of South African Plants. Strelitzia 25. South African National Biodiversity Institute, Pretoria.
Scott-Shaw, C.R. 1999. Rare and threatened plants of KwaZulu-Natal and neighbouring regions. KwaZulu-Natal Nature Conservation Service, Pietermaritzburg.
Van Wyk, A.E. and Schrire, B.D. 1986. A remarkable new species of Colubrina (Rhamnaceae) from Pondoland. South African Journal of Botany 52(4):379-382.
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Citation |
| von Staden, L., Victor, J.E. & van Wyk, A.E. 2022. Colubrina nicholsonii A.E.van Wyk & Schrire. National Assessment: Red List of South African Plants version . Accessed on 2025/05/17 |
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