Gasteria thunbergii

Assessor: Sarah Schumann

Sensitive in 2010
No
Family
Asphodelaceae
Reason for the sensitivity status
This species is thought to be a potential target as it is mildly ornamental and at risk of small scale illegal collection however collection is not known at this point. Several others of the genus are known to be targeted, exploited and illegally removed from the wild, causing population decline. Evidence shows that the Gasteria genus is in high demand in international horticultural trade. Few known locations makes this species highly vulnerable to population loss. Releasing data on this species can 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 Rare as it is known from two sites and is not threatened (van Jaarsveld & Raimondo, 2007). 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. Several species of the Gasteria genus were among those targeted and confiscated during recent criminal prosecutions of illegal plant collecting (Confiscation Lists (2021) provided by SANParks Sendelingsdrift Botanic Garden and Kirstenbosch Botanical Garden). This species is thought to be a potential target as it is mildly ornamental and at risk of small scale illegal collection however collection is not known at this point (Personal communication, S. Molteno, 5 August 2022).

van Jaarsveld, E.J. & Raimondo, D. 2007. Gasteria thunbergii N.E.Br. National Assessment: Red List of South African Plants version 2020.1.

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 has an extent of occurrence of 25 kmĀ² and is known from two sites (van Jaarsveld & Raimondo, 2007).

van Jaarsveld, E.J. & Raimondo, D. 2007. Gasteria thunbergii N.E.Br. 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

Range restriction and few known sites makes this species highly vulnerable to population loss. Were exploitation to occur, recruitment and recovery may be poor.