Disa tenella subsp. tenella | SANBI Sensitive Species

Assessor: Sarah Schumann

Sensitive in 2010

Family

Orchidaceae

Reason for the sensitivity status

Other species in this genus are known to be threatened by collection of wild individuals. Few known locations of occurrence with existing threats causing population decline makes this subspecies vulnerable to further population loss. Were exploitation to also occur, recruitment and recovery may be poor. Releasing data on this subspecies could exacerbate threat and vulnerability.

This species is either similar to 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 more than 50% of its known locations has been lost to development as well as experiencing ongoing population decline due to agriculture and alien invasive plant encroachment (von Staden et al. 2012). Other species in this genus are known to be threatened by collection of wild individuals (von Staden et al. 2012).

von Staden, L., Ebrahim, I., von Witt, C., Bytebier, B. & Liltved, W.R. 2012. Disa tenella (L.f.) Sw. subsp. tenella. National Assessment: Red List of South African Plants version 2020.1.

von Staden, L., Oliver, E.G.H. & Raimondo, D. 2012. Disa longicornu L.f. 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 2105 km² whereby three to four location remain (von Staden et al. 2012).

von Staden, L., Ebrahim, I., von Witt, C., Bytebier, B. & Liltved, W.R. 2012. Disa tenella (L.f.) Sw. subsp. tenella. 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

Few remaining locations of occurrence and several threats places the persistence of this species at risk. Were exploitation to occur, recovery may be poor.

Reference file

Disa tenella ssp. tenella Threatened Species Programme _ SANBI Red List of South African Plants.pdf768.91 KB