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Scientific Name | Leucadendron macowanii E.Phillips |
Higher Classification | Dicotyledons |
Family | PROTEACEAE |
Common Names | Acacia-leaf Conebush (e) |
National Status |
Status and Criteria | Critically Endangered B1ac(iv)+2ac(iv); C2b |
Assessment Date | 2020/06/05 |
Assessor(s) | A.G. Rebelo & D. Raimondo |
Justification | Leucadendron macowanii is an endemic to moist wetland sites on the Cape Peninsula in South Africa, this species has an extent of occurrence (EOO) of 53 km² and area of occupancy (AOO) of 24 km². From the original population only one small subpopulation remains, the only other known wild subpopulation is now locally extinct due to urban expansion. Extreme fire-related fluctuations in number of mature individuals have been observed in the remaining wild subpopulation between 1973 and 2020, the current size of the subpopulation is less than 100 plants. Many attempts have been made to introduce more subpopulations on the Cape Peninsula and near Hermanus, but the majority of these have proven not to be viable. However, one reintroduced subpopulation has managed to recruit viable individuals and is now included in the wild population however the number of individuals at this population are low fewer than 50 mature individuals. This species is highly specific in requiring moist habitat but is easily outcompeted by other wetland species especially Typha capensis. Other threats include inappropriate fire management, alien clearing (it tends to be mistaken for Acacia cyclops), and seed predation. The two currently subpopulations are severely fragmented, and both fluctuate in response to fire. It therefore qualifies as Critically Endangered under criteria B and C. |
Distribution |
Endemism | South African endemic |
Provincial distribution | Western Cape |
Range | This species is endemic to the Cape Peninsula, in the Western Cape Province, South Africa. |
Habitat and Ecology |
Major system | Terrestrial |
Major habitats | Cape Flats Dune Strandveld, Peninsula Sandstone Fynbos, Hangklip Sand Fynbos |
Description | It occurs in damp sands near streams, 60-200 m. Mature individuals are killed by fires, and only seeds survive. Seeds are stored in fire-resistant inflorescences, and released after fires. It is dioecious, with wind-pollinated male and female flowers occurring on separate plants. Flowering is rapid, at two years of age. |
Threats |
This species had a historic subpopulation recorded from Wynbeg hill, it has gone extinct here due to vineyard cultivation and urban development, the date of extinction is not known but could have been any time between 1988 and 1960. The only other original natural subpopulation is from Smitswinkel Stream. This subpopulation is still extant and is threatened by invasive alien plant species and by clearing of invasive. This species is easily mistaken for an Acacia and both A. longifolia and A. cyclops occur within the same stand and in adjacent stands of L. macowanii. This means alien-clearing teams need special training before working near subpopulation this does not always take place. Since this is a serotinous species, population collapses mean lack of seed banks, this species is thus vulnerable to fire related population fluctuations. Population fluctuations where numbers of mature individuals change by orders of magnitude have been documented as this species has been monitored since 1973. Predation of serotinous seed bank by insects, has also been recorded and resistance to burn the only remaining wild subpopulation due to proximity to urban areas was a problem between 1990 and 2005. |
Population |
Apart from the extinct Wynberg subpopulation, the only natural subpopulation of this species is at Smitswinkel Bay. At present plants are found at Smitswinkel Bay over a 2 km long area, with half the subpopulation occurring within the boundaries of the Table Mountain National Park and half on private land. Historically the subpopulation extended westwards by perhaps another kilometre but this area is now highly degraded as it is an Ostrich farm. In 1973 some 1 000 plants were noted (H. Langley, pers. comm.). In 1982 there were 160 plants with a further eight plants west. Since 1985 the largest subpopulation, covering 5 ha, has dropped to 100 in 1990 to 50 in 1995, to about five plants within the reserve in 2000. Several plants were killed to create a fire belt in 1994. Within the reserve the plants have become senescent and died. In 2005 due to lack of fire there were fewer than 20 individuals, the area was burned in April 2005, with good recruitment of several hundred seedlings. Estimates were 7400 plants in 2006 and 5500 in 2009 (D. McDermid, pers. comm.), but these are aerial extrapolations from seven plots and were possibly too high (Rebelo, pers. obs.). Records posted on iNaturalist between 2017 and 2019 show the plants are once again very large and some are senescent and in need of another burn the total population has dropped again below 100 plants (Rebelo pers. obs).
A number of reintroductions of this species have taken place, many have not succeeded, these include Gifkommetjie; Booi Se Skerm; Soetdal Wetland in Tokai and out of range introduction in the Kleinrivier Mountains at Fernkloof Nature Reserve.
A planted subpopulation at Silvermine Dam mentioned in Hall and Veldhuis (1985) which consisted of 144 plants in 1985, was reputedly established at the municipal nursery at Silvermine to form a seedbank to allow the introduction of the plant in suitable natural sites. This planting dates back to around 1979-80 when seed from 30-40 cones were germinated and planted out above the Silvermine Dam wall on the north side where they 'thrived.' While none of these plants were found by atlassers from 1991 and 2005, a health stand has been recorded on iNaturalist in 2017 consisting of between 50 and 100 individuals. Since this subpopulation has managed to persist for 37 years and has survived and recruited following a minimum of three fire cycles it can now be considered to be part of the wild population.
There are therefore two subpopulations of the species which both fluctuate in response to fire season and interval length.
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Population trend | Decreasing |
Conservation |
In 1985 part of the largest subpopulation was included in the Cape of Good Hope section of the Table Mountain National Park. However, over 10% of plants were killed while bush cutting a fire belt in 1994. Reluctance to burn this subpopulation has resulted in massive dieback due to senescence: it was burned in April 2005. |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | Leucadendron macowanii E.Phillips | CR B1ac(iv)+2ac(iv) | Raimondo et al. (2009) | Leucadendron macowanii E.Phillips | Endangered | Hilton-Taylor (1996) | Leucadendron macowanii E.Phillips | Endangered | Hall et al. (1980) | |
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.
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.
Helme, N.A. and Trinder-Smith, T.H. 2006. The endemic flora of the Cape Peninsula, South Africa. South African Journal of Botany 72(2):205-210.
Hilton-Taylor, C. 1996. Red data list of southern African plants. Strelitzia 4. South African National Botanical 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.
Rebelo, T. 2001. Sasol Proteas: A field guide to the proteas of southern Africa. (2nd ed.). Fernwood Press, Vlaeberg, Cape Town.
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Citation |
Rebelo, A.G. & Raimondo, D. 2020. Leucadendron macowanii E.Phillips. National Assessment: Red List of South African Plants version . Accessed on 2025/02/11 |