|
Scientific Name | Pachypodium namaquanum (Wyley ex Harv.) Welw. |
Higher Classification | Dicotyledons |
Family | APOCYNACEAE |
Common Names | Elephant's Trunk (e), Halfmens (a) |
National Status |
Status and Criteria | Critically Endangered A4acde |
Assessment Date | 2022/10/20 |
Assessor(s) | N.N. Mhlongo & P.C.V. Van Wyk |
Justification | This species has an extent of occurrence (EOO) of 18 491 km² and an area of occupancy (AOO) of 232 km². The population has experienced a decline of at least 60-80% in the past two generations (200 years) due to the combined impacts of the ongoing drought, habitat loss and degradation. It is also impacted by illegal collecting for the specialist succulent trade. Future climate models predict severe impacts to the species and this combined with illegal harvesting will result in further 50% declines over the next generation. It therefore qualifies as Critically Endangered under criterion A. |
Distribution |
Endemism | Not endemic to South Africa |
Provincial distribution | Northern Cape |
Range | This species occurs in the Northern Cape where it is found in Pella and Steinkopf and extends to southern Namibia where it occurs from Rosh Pinah to near Goodhouse. |
Habitat and Ecology |
Major system | Terrestrial |
Major habitats | Aggeneys Gravel Vygieveld, Eenriet Plains Succulent Shrubland, Central Richtersveld Mountain Shrubland, Namaqualand Blomveld, Namaqualand Klipkoppe Shrubland, Bushmanland Arid Grassland, Richtersberg Mountain Desert, Noms Mountain Desert |
Description | Plants occur on rocky arid slopes. |
Threats |
| This species has been severely impacted by drought and within South Africa several subpopulations occurring along the lower slopes of mountains have been recorded to have gone locally extinct. There is also an ongoing threat of illegal collecting for the horticultural and medicinal trades, which has led to significant declines to this once common species. Twelve plants were reported to have been poached from the Richtersveld National Park, however many more are likely to have been removed from the wild, particularly in Umdaus, Nababib and east of Eksteenfontein without anyone noticing. Plants are targeted by animals such as porcupines and baboons during periods of harsh environmental conditions (Conrad Geldenhuys, pers. comm 2022). This herbivory often leads to rot due to the damage caused to the stems (Conrad Geldenhuys, pers. comm 2022). The population in the Richtersveld National Park was previously attacked by a boring worm, which resulted in the death of several plants (Kirsti Nghidinwa, 2016). Signs of larvae damage was once again observed in one of the dead plants in October 2022, however drought related mortality is more severe with 80% of the biggest subpopulation in the Richtersveld National Park having been decimated as a result. Livestock farming was a serious threat to this species in the past, however this has since ceased though the degradation caused to the species' habitat is still continuous. Grazing by goats in what was previously inaccessible terrain in the mountains also threatens this species' persistence. It is also impacted by mining, which releases unwanted heavy mineral dust into the species' habitat, which is particularly harmful to the seedlings. |
Population |
The population has suffered an overall decline of between 60-80% over the last two generations (200 years). One of the largest recorded subpopulations from the Richtersveld prior to 2016 consisted of more than 2000 plants, which following the severe drought are now limited to just a handful of individuals. Match photographs undertaken by the Plant Conservation Unit from the University of Cape Town show a number of declining subpopulations over the last 100 years, with these documented prior to the severe declines that have happened since 2016. Recruitment has been observed in the Richtersveld for this species, however plants do not form persistent soil seedbanks and once a subpopulation has been severely reduced, it will take a long period to regenerate the numbers. Plants are struggling to produce viable seed due to the ongoing drought and seedlings are not surviving the drought conditions. The number of available pollinators also seems to have greatly decreased. The species grows by 0.5-1 centimetres per year in cultivation and is expected to grow at a third of this rate in situ. Given this, the average age of matured individuals is expected to be at least 100 years (generation length). At the current mortality rates, the species faces a high risk of extinction.
|
Population trend | Decreasing |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | | Pachypodium namaquanum (Wyley ex Harv.) Welw. | Least Concern | Raimondo et al. (2009) | | Pachypodium namaquanum (Wyley ex Harv.) Welw. | Vulnerable | Hilton-Taylor (1996) | | Pachypodium namaquanum (Wyley ex Harv.) Welw. | Vulnerable | Hall et al. (1980) | |
Bibliography |
Hall, A.V., De Winter, M., De Winter, B. and Van Oosterhout, S.A.M. 1980. Threatened plants of southern Africa. South African National Scienctific Programmes Report 45. CSIR, Pretoria.
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.
Snijman, D.A. 2013. Plants of the Greater Cape Floristic Region 2: The extra Cape flora. Strelitzia 30. South African National Biodiversity Institute, Pretoria.
|
Citation |
| Mhlongo, N.N. & Van Wyk, P.C.V. 2022. Pachypodium namaquanum (Wyley ex Harv.) Welw. National Assessment: Red List of South African Plants version . Accessed on 2025/04/20 |
Comment on this assessment
