Riversdale Freesia

Taxonomy
Scientific Name
Freesia fergusoniae L.Bolus
Higher Classification
Monocotyledons
Family
IRIDACEAE
Common Names
Riversdale Freesia (e)
National Status
Status and Criteria
Vulnerable B1ab(i,ii,iii,iv,v)
Assessment Date
2021/09/27
Assessor(s)
D. Raimondo, P. Goldblatt, L. von Staden & T. Patel
Justification
This species has an extent of occurrence (EOO) of 8994 km², and an area of occupancy (AOO) of 204 km². Twenty one severely fragmented subpopulations remain after 73% of its habitat has been transformed and fragmented, predominantly due to agricultural expansion. It continues to decline due to ongoing habitat loss and degradation. It is therefore listed as Vulnerable under criteria B.
Distribution
Endemism
South African endemic
Provincial distribution
Western Cape
Range
It is endemic to the Western Cape of South Africa, where it is found from Swellendam to Oudtshoorn and Mossel Bay.
Habitat and Ecology
Major system
Terrestrial
Major habitats
Mossel Bay Shale Renosterveld, Eastern Ruens Shale Renosterveld, Ruens Silcrete Renosterveld, Central Ruens Shale Renosterveld, Garden Route Shale Fynbos, Swellendam Silcrete Fynbos, Montagu Shale Renosterveld, Garden Route Granite Fynbos, Potberg Ferricrete Fynbos
Description
It occurs in clay soils in renosterveld.
Threats
73% of this species' habitat is already transformed (calculated using landcover data in GIS), predominantly for crop cultivation, resulting in the fragmentation and isolation of renosterveld vegetation, and loss is ongoing. Remaining fragments are often overstocked with livestock, and severe overgrazing is causing ongoing degradation of remaining habitat. Some subpopulations are also threatened by urban expansion, competition from alien invasive plants and too infrequent fire: this species does not flower in very old, senescent renosterveld, but fire is often excluded from small fragments.
Population

Eleven out of 18 recorded subpopulations are from small, isolated fragments and roadside verges, and therefore the population is considered severely fragmented. A continuing population decline is inferred from ongoing habitat loss and degradation. 20 plants were observed in a 10x10 meter otach in 2017, while another observation noted 5 plants in a 5x5 patch both near Aalyndal. 10-50 plants were observed in a subpopulation near Herbertsdale road in 2014.


Population trend
Decreasing
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Freesia fergusoniae L.BolusVU B1ab(i,ii,iii,iv,v)2020.1
Freesia fergusoniae L.BolusVU B1ab(ii,iii,iv,v)2012.1
Freesia fergusoniae L.BolusVU B1ab(ii,iii,iv,v)Raimondo et al. (2009)
Bibliography

Goldblatt, P. 1982. Systematics of Freesia Klatt (Iridaceae). Journal of South African Botany 48(1):39-91.


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.


Manning, J.C. and Goldblatt, P. 2010. Botany and horticulture of the genus Freesia. Strelitzia 27:1-114. South African National Biodiversity 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.


Citation
Raimondo, D., Goldblatt, P., von Staden, L. & Patel, T. 2021. Freesia fergusoniae L.Bolus. National Assessment: Red List of South African Plants version . Accessed on 2024/06/14

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Distribution map

© N. van Berkel


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