Idlula

Taxonomy
Scientific Name
Begonia homonyma Steud.
Higher Classification
Dicotyledons
Family
BEGONIACEAE
Synonyms
Begonia caffra Meisn., Begonia rudatisii Irmsch.
Common Names
Idlula (z), Wildebegonia (a)
National Status
Status and Criteria
Endangered C2a(i)
Assessment Date
2008/03/15
Assessor(s)
V.L. Williams, N.R. Crouch, T. McLellan & L. von Staden
Justification
Population size is estimated to be <2500 mature individuals and no one subpopulation is estimated to have more than 250 plants. These estimates are derived from counts of plants in nine subpopulations at sites across the range. The maximum recorded number of plants per subpopulation is 50. The species is rare in its forest habitat. Caudices are used for traditional medicine and have been recorded occasionally in the KwaZulu-Natal traditional medicine markets. Small populations are declining due to destructive harvesting.
Distribution
Endemism
South African endemic
Provincial distribution
Eastern Cape, KwaZulu-Natal
Range
Eastern Cape and KwaZulu-Natal coast, from the Kei River to Stanger and around Pietermaritzburg. Isolated record from the southern foot of the Lebombo Mountains in northern KwaZulu-Natal.
Habitat and Ecology
Major system
Terrestrial
Major habitats
Northern Coastal Forest, Southern Coastal Forest, Scarp Forest, Southern Mistbelt Forest
Description
Deeply shaded sites on south-facing slopes in forests, rocky sites, 20-900 m.
Threats
Begonia homonyma caudices are used for traditional medicine and have been recorded occasionally in the KwaZulu-Natal traditional medicine markets (Cunningham 1988, Von Ahlefeldt et al. 2003). Cunningham (1988) estimated the annual demand for the caudices to be 54 bags (50kg-size) per annum between 54 traders in the KwaZulu-Natal region, and classed the species vulnerability to exploitation as 'indeterminate' - i.e. it appeared to be heavily exploited but more data were required. It is likely to be traded in the Johannesburg markets as well, but a positive identification of the plants has not been made thus far (V.L. Williams, pers. obs., 2008). While declines have probably occurred due to harvesting for the traditional medicine trade, the extent and time-frame are not known.
Population

Nine subpopulations, scattered over seven Quarter Degree Squares (QDSs) were counted by Matolweni et al. (2000) and N.R. Crouch. There are an average of 22.3 plants per subpopulation and 28.7 plants per QDS. The maximum number of plants per subpopulation was 50. Hence, the total population size in 16 known QDSs is estimated to be <1000 plants. The plants counted by Matolweni and Crouch probably included juveniles, hence the total number of mature plants is also expected to be less than 1000. Given the species' known rarity, it is unlikely that it will be located in too many more new QDS. It is also unlikely that a subpopulation will have more than 250 mature plants. The probability of extinction of any single subpopulation is high, since the populations are so small (Matolweni et al. 2000).


Population trend
Decreasing
Conservation
Oribi George and Umtamvuna Nature Reserve.
Notes
Taxonomy: Tracy McClellan from the University of the Witwatersrand recognises Begonia homonyma and B. dregei as separate, but closely related, species with high levels of variation among subpopulations in the shape of the leaves (Matolweni et al. 2000). Allozyme data, however provides no support for the recognition of B. dregei and B. homonyma as distinct species. However, according to Neil Crouch, there are enough morphological differences between the two species to be able to separate them. Distribution data in this assessment is based on specimens identified by Neil Crouch, Tracy McClellan and Vivienne Williams.
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Begonia homonyma Steud.EN C2a(i)Raimondo et al. (2009)
Begonia homonyma Steud.VU Scott-Shaw (1999)
Begonia rudatisii IrmscherEN Scott-Shaw (1999)
Begonia homonyma Steud.Rare Hilton-Taylor (1996)
Bibliography

Cunningham, A.B. 1988. An investigation of the herbal medicine trade in Natal/KwaZulu. Investigational Report No. 29. Institute of Natural Resources, Pietermaritzburg.


Hilliard, O.M. 1976. Begoniaceae. In: J.H. Ross (ed). Flora of Southern Africa 22:136-144. Botanical Research Institute, Pretoria.


Hilton-Taylor, C. 1996. Red data list of southern African plants. Strelitzia 4. South African National Botanical Institute, Pretoria.


Matolweni, L.O., Balkwill, K. and McLellan, T. 2000. Genetic diversity and gene flow in the morphologically variable, rare endemics Begonia dregei and Begonia homonyma (Begoniaceae). American Journal of Botany 87(3):431-439.


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.


Scott-Shaw, C.R. 1999. Rare and threatened plants of KwaZulu-Natal and neighbouring regions. KwaZulu-Natal Nature Conservation Service, Pietermaritzburg.


Von Ahlefeldt, D., Crouch, N.R., Nichols, G., Symmonds, R., McKean, S., Sibiya, H. and Cele, M.P. 2003. Medicinal plants traded on South Africa's eastern seabord. Porcupine Press, Durban.


Citation
Williams, V.L., Crouch, N.R., McLellan, T. & von Staden, L. 2008. Begonia homonyma Steud. National Assessment: Red List of South African Plants version 2020.1. Accessed on 2022/05/20

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Distribution map


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