Taxonomy
Scientific Name
Babiana blanda (L.Bolus) G.J.Lewis
Higher Classification
Monocotyledons
Family
IRIDACEAE
National Status
Status and Criteria
Endangered A4ce; B1ab(ii,iii,v)+2ab(ii,iii,v)
Assessment Date
2021/02/09
Assessor(s)
D. Raimondo, R. Koopman, J. van der Merwe, N.A. Helme & J.C. Manning
Justification
This species has an extent of occurrence (EOO) of 154 km², and an area of occupancy (AOO) of 40 km². Herbarium records indicate that this species was widespread in wetlands between Milnerton and Malmesbury but it has lost 88% of its habitat to urban and agricultural development and remains at only four locations where the population is declining due to ongoing habitat loss and degradation. A population reduction of more than 50% is suspected to take place between 2010 and 2025 (generation length 5 - 10 years) based on recent observed declines between 2010 and 2022 and future losses of sections of the population zoned for housing development that will take place before 2025. It is therefore listed as Endangered under criteria A and B.
Distribution
Endemism
South African endemic
Provincial distribution
Western Cape
Range
It is endemic to South Africa, and is found in the Western Cape Province, extending from Darling to Milnerton.
Habitat and Ecology
Major system
Terrestrial
Major habitats
Swartland Shale Renosterveld, Swartland Granite Renosterveld, Swartland Silcrete Renosterveld
Description
It occurs in seasonally damp, sandy or loamy flats in shale and granite renosterveld.
Threats
This species has lost 88% of its habitat (calculated using landcover data in GIS) to urban and agricultural expansion. Remaining subpopulations occur on isolated fragments and are severely degraded by alien invasive plants. Extremely hot fires linked with high densities of invasive plants cause this species to decline. Where attempts are being made to clear aliens for example in the Witzands Aquifer Nature Reserve the ecological balance is difficult to regain and many individuals of this species are being decimated by porcupines and gerbils which no longer have their natural predators present. One of the largest remaining subpopulations was lost to the widening of a firebreak in 2020.
Population

It was frequently collected in the area between Milnerton and Mamre from the 1940s to 1960s, but then not seen again for many years. Iridaceae expert Peter Goldblatt searched for remaining subpopulations of this species for more than 20 years, and the species was presumed extinct. In 2006 a large subpopulation numbering 300-500 mature individuals was discovered near Philadelphia, and in 2007 a second, smaller subpopulation of between 100 and 300 plants was found near Malmesbury on the Klipkoppie municipal commonage. One third of this Malmesbury subpopulation will be lost to low cost housing development that will take place between 2021 and 2025. A further two subpopulations have been found to be extant since 2017. One of these occurs in the Witzands Aquifer Nature Reserve where between 1500 plants were recorded between 2018 and 2020 but 500 of these were lost to the widening of firebreak in 2020. The remaining plants in this subpopulation are rapidly declining due to predation by porcupines and gerbils. The last subpopulation is small with only 50 plants in a 2 ha remnant occurring at Melkbosstrand. Subpopulations are isolated and continue to decline due to ongoing habitat degradation at all sites. A decline of 50% of the population is suspected to take place between 2010 and 2025 (generation length 5 - 10 years). Interestingly there are hybrids of Babiana blanda and Babiana villosula occurring in the Agter Paarl and Klapmuts region these hybrid subpopulations have not been included in this assessment.


Population trend
Decreasing
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Babiana blanda (L.Bolus) G.J.LewisCR B1ab(iii)Raimondo et al. (2009)
Bibliography

Goldblatt, P. and Manning, J.C. 2000. Cape Plants: A conspectus of the Cape Flora of South Africa. Strelitzia 9. National Botanical Institute, Cape Town.


Goldblatt, P. and Manning, J.C. 2007. A revision of the southern African genus Babiana, Iridaceae, Crocoideae. Strelitzia 18:1-97. South African National Biodiversity Institute, Pretoria.


Goldblatt, P. and Manning, J.C. 2020. Iridaceae of southern Africa. Strelitzia 42. South African National Biodiversity Institute, Pretoria.


Manning, J., Goldblatt, P. and Snijman, D. 2002. The color encyclopedia of Cape bulbs. Timber Press, Portland/Cambridge.


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.


Citation
Raimondo, D., Koopman, R., van der Merwe, J., Helme, N.A. & Manning, J.C. 2021. Babiana blanda (L.Bolus) G.J.Lewis. National Assessment: Red List of South African Plants version . Accessed on 2024/07/18

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Distribution map

© R. Koopman

© R. Koopman

© R. Koopman

© R. Koopman

© R. Koopman

© R. Koopman

© J.C. Manning


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