| Scientific Name | Merwilla plumbea (Lindl.) Speta | Higher Classification | Monocotyledons | Family | HYACINTHACEAE | Synonyms | Merwilla natalensis (Planch.) Speta, Scilla kraussii Baker, Scilla natalensis Planch., Scilla plumbea Lindl. | Common Names | Blousalngkop (a), Blue Squill (e), Ichitha (z), Imbizenkulu (z), Inguduza (z), Kherere (ss), Ubulika (z) |
National Status | Status and Criteria | Near Threatened A2bd | Assessment Date | 2008/11/04 | Assessor(s) | V.L. Williams, A.B. Cunningham & D. Raimondo | Justification | A highly sought after species that has been exploited over most of its range for medicinal use. Individuals are long-lived, the average age of mature individuals is suspected to be 25 years. A minimum of a 25 % decline over the past three generations (75 years) is suspected based on a number of studies that document very high volumes of plants traded in muti markets, an overall decreases in the average size of bulbs traded, and anecdotal harvester reports that plants are becoming difficult to find. |
Distribution | Endemism | Not endemic to South Africa | Provincial distribution | Eastern Cape, Free State, KwaZulu-Natal, Mpumalanga |
Habitat and Ecology | Major system | Terrestrial | Major habitats | Northern Zululand Mistbelt Grassland, Pondoland-Ugu Sandstone Coastal Sourveld, Scarp Forest, Northern Drakensberg Highland Grassland, Wakkerstroom Montane Grassland, Paulpietersburg Moist Grassland, KaNgwane Montane Grassland, Barberton Montane Grassland, Northern Escarpment Dolomite Grassland, Northern Escarpment Quartzite Sourveld, KwaZulu-Natal Coastal Belt Grassland, Steenkampsberg Montane Grassland, Eastern Valley Bushveld, Mabela Sandy Grassland, Dry Coast Hinterland Grassland, Moist Coast Hinterland Grassland, Midlands Mistbelt Grassland, Sekhukhune Mountain Bushveld, Barberton Serpentine Sourveld, Zululand Lowveld, Tzaneen Sour Bushveld, KwaZulu-Natal Hinterland Thornveld, KwaZulu-Natal Sandstone Sourveld, Woodbush Granite Grassland |
Threats | | A minimum of a 25% decline over the past three generations (75 years) is suspected based on a number of studies that report: high volumes of plants traded in muthi markets; harvesters reporting that plants are becoming scarce; and overall decreases in the average size of bulbs traded. Merwilla plumbea (formerly Scilla natalensis) is a highly sought after species that has been exploited over most of its range. Cunningham (1988) recorded M. plumbea as the most prevalent and in-demand species in the KwaZulu-Natal muthi markets; the number of bags (50kg-size) estimated to be sold annually by 54 herb-traders was 774, and the species was classed as 'declining' - i.e. a species that was recently widespread but was likely to become vulnerable and continue to decline if destruction of the wild populations continued. The herb-traders and herbalists in the region consistently nominated the species as one the plants they considered to be scarce. Furthermore, Cunningham (1988) estimated there were about 94.2±28.9 bulbs per bag (mean diameter equals 7.3±1.8 cm) - hence the number of bulbs potentially traded annually was >73 000.
Williams et al. (2007a) list it as occurring in 72% of muthi shops in the Witwatersrand in 1994, and further estimated that about 1350 bags of bulbs were bought annually by the muthi shops in the region. It was the fourth most prevalent species in the shops (after Eucomis autumnalis); it was regarded as the most popular species by the traders (rank shared with E. autumnalis); and, it was nominated by 12% of them as becoming scarce (Williams et al. 2000). Another study by Williams et al. (2007b) showed that the mean size of the bulbs decreased between 1995 and 2001, but not significantly. The number of bulbs sold in the muthi shops in 1994 was also estimated to be >266 000 (Williams et al. 2007b). In the Faraday muthi market in Johannesburg in 2001, 27% of traders sold the species and 135 bags were estimated to be bought annually between all the traders in the market (Williams 2003), and the number of bulbs was equivalent to 38 000 (Williams et al. 2007b). This is suspected to be a significant under-estimate of the total number of bulbs harvested for sale in the market. The species was considered to be becoming scarce.
Mander (1988) estimated that there had been a 25% increase in the travelling time to get to M. plumbea harvesting localities; this increase represented an extra one hour or more, and gatherers were having to travel greater distances to more remote locations. Mander's estimates for the quantity traded annually in the Durban medicinal plant trade was 95.5 tonnes, which was equivalent to about 432 000 bulbs traded annually was 432 000.
Scott-Shaw (1999) cites M. plumbea as being locally abundant where it hasn't been exploited, but is becoming very rare and extirpated in many areas, particularly the Midlands and coastal interior.
In a more recent study in 2006 by Williams et al. 2007c, 38% of traders in the Faraday market and 90% of traders in the Warwick market sold M. plumbea. More than 80% of the traders bought plants from suppliers who came to the markets with bags of bulbs. Warwick traders said that 86% of the bulbs were harvested in KwaZulu-Natal and 14% from the Eastern Cape. Faraday traders in Johannesburg, however, cited 35% of the stock has having been harvested in KwaZulu-Natal, 39% from Mpumalanga and 17% from the Free State. The Eastern Cape, Limpopo and Swaziland were also cited as harvesting localities. Most of the bulbs in both markets were in the 5-10cm diameter size-class (41% in Faraday; 49% in Warwick), with a smaller proportion in the >10cm size-class (34% Faraday; 26% Warwick). From historical data, there appears to be an increased prevalence of bulbs in the <5cm size-class since 1994. The number of bulbs estimated to be sold annually in Faraday and Warwick in 2006 was 235 872 bulbs and 1 851 580 bulbs, respectively. |
Population | Population trend | Decreasing |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | | Merwilla plumbea (Lindl.) Speta | NT A2bd | Raimondo et al. (2009) | | Scilla natalensis Planch. | VU | Scott-Shaw (1999) | | Scilla natalensis Planch. | Insufficiently Known | Hilton-Taylor (1996) | | Scilla plumbea Lindl. | Rare | Hilton-Taylor (1996) | | Scilla plumbea Lindl. | Uncertain | Hall et al. (1980) | |
Bibliography | Cunningham, A.B. 1988. An investigation of the herbal medicine trade in Natal/KwaZulu. Investigational Report No. 29. Institute of Natural Resources, Pietermaritzburg.
Douwes, E., Crouch, N.R. and Symmonds, R. 2001. Blue Squill in the Red: Scilla natalensis as a conservation charge. PlantLife 24:14-19.
Hall, A.V., De Winter, M., De Winter, B. and Van Oosterhout, S.A.M. 1980. Threatened plants of southern Africa. South African National Scienctific Programmes Report 45. CSIR, Pretoria.
Hilton-Taylor, C. 1996. Red data list of southern African plants. Strelitzia 4. South African National Botanical Institute, Pretoria.
Mander, M. 1998. Marketing of indigenous medicinal plants in South Africa: a case study in KwaZulu-Natal. Food and Agriculture Organization of the United Nations, Rome.
Pooley, E. 2003. Mountain flowers: a field guide to the flora of the Drakensberg and Lesotho. Natal Flora Publications Trust, Durban.
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.
Williams, V., Raimondo, D. and Cunningham, A.B. 2007. Trade, bulb age and impacts on Merwilla plumbea (Hyacinthaceae). Final report to IDRC, New Delhi.
Williams, V.L. 2007. The design of a risk assessment model to determine the impact of the herbal medicine trade on the Witwatersrand on resources of indigenous plant species. Unpublished PhD Thesis, University of the Witwatersrand, Johannesburg.
Williams, V.L., Balkwill, K. and Witkowski, E.T.F. 2007. Size-class prevalence of bulbous and perennial herbs sold in the Johannesburg medicinal plant markets between 1995 and 2001. South African Journal of Botany 73(1):144-155.
Williams, V.L., Witkowski, T.F. and Balkwill, K. 2007. Volume and financial value of species traded in the medicinal plant markets of Gauteng, South Africa. International Journal of Sustainable Development & World Ecology 14(6):584-603.
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Citation | | Williams, V.L., Cunningham, A.B. & Raimondo, D. 2008. Merwilla plumbea (Lindl.) Speta. National Assessment: Red List of South African Plants version . Accessed on 2025/05/19 |
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