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Euphorbia knobelii

Assessor: Sarah Schumann

Sensitive in 2010
No
Family
Euphorbiaceae
Reason for the sensitivity status
There have been several recorded confiscations of species of the Euphorbia genus from illegal collection. This genus is in demand and of popular interest in international horticultural trade. A small population size with existing threats causing population decline makes this species vulnerable to further population loss. Were exploitation to also occur, recruitment and recovery may be poor. Releasing data on this species could exacerbate threat and vulnerability.
This species is either similar to another sensitive species or belongs to a group containing sensitive species, and is extremely rare in the wild. The localities of wild populations need to be protected to avoid loss to exploitation, which, due to its rarity, could drive the species to extinction within a very short time.
Exploitation extent
Uncertain - No data exists yet showing that this species is exploited in the wild, however it has one or more relatives or look-alike species (found in South Africa or globally) that are known to be utilised. This species has a similar life form or other relevant traits to its exploited relative(s), making it highly likely that it would be exploited for the same purposes.
Justification and references

According to the SANBI Red List Assessment, this species is Endangered as it is experiencing ongoing population decline due to habitat degradation and disease (Archer et al. 2016; Hahn, 2013; Peckover, 1999). This genus is currently in demand and of popular interest in international horticultural trade, as indicated by several online marketplace, e-commerce and auction sites. Plants of this genus were among those targeted and/or confiscated during recent criminal prosecutions of illegal plant collecting. There have been several recorded confiscations of Euphorbia species from illegal collection (Confiscation List (2018-2021) provided by Cape Nature, SANParks Sendelingsdrift Botanic Garden, Karoo Desert Botanical Garden, and Kirstenbosch Botanical Garden). This suggests that this genus is being targeted and that this species may be at risk.

Archer, R.H., von Staden, L., Victor, J.E. & Hahn, N. 2016. Euphorbia knobelii Letty. National Assessment: Red List of South African Plants version 2020.1.

 

Hahn, N. 2013. Rare, endangered and endemic flora of the North West Province. Unpublished Report to the Department of Economic Development, Conservation and Tourism, North West Provincial Government.

Peckover, R.G. 1999. Euphorbia perangusta on the brink of extinction: Can we help? Veld & Flora 85(4):170-171.

Population vulnerability
Population is vulnerable: size is <= 2500 mature individuals OR the number of known subpopulations is <= 5 OR range is <= 100km2 OR species at risk of localised extinctions
Justification and references

This taxon's population has reduced by 50-60% in 30 years, has an extent of occurrence of 1277 km² and is known from two to five locations (Archer et al. 2016).

Archer, R.H., von Staden, L., Victor, J.E. & Hahn, N. 2016. Euphorbia knobelii Letty. National Assessment: Red List of South African Plants version 2020.1.

Targeted demographics
Unknown.
Regeneration potential
This species has a slow population growth rate, or the growth rate varies depending on habitat, and there is a poor chance the wild populations will recover from exploitation OR a collector might feasibly harvest the entire extant population removing the chance of subsequent recruitment.
Justification and references

A small population size with existing threats causing population decline makes this species vulnerable to further population loss. Were exploitation to also occur, recruitment and recovery may be poor. 

Reference file
euphorbia _ eBay.pdf1.06 MB
Euphorbia Aucfan.pdf1.75 MB
Euphorbia knobelii Threatened Species Programme _ SANBI Red List of South African Plants.pdf564.01 KB