Marasmodes oligocephala DC.
|Marasmodes polycephala DC. var. oligocephala (DC.) Harv.|
Status and Criteria
Endangered B1ab(iii,v)+2ab(iii,v); C2a(i)
|A.R. Magee, L. von Staden & D. Raimondo|
|A small population of fewer than 500 mature individuals remain on four renosterveld remnants within a small area (EOO 7 km²). The largest subpopulation consists of about 200 mature individuals. This species continues to decline due to ongoing habitat degradation as well as competition from alien invasive plants.|
|South African endemic|
|Atlantis to Malmesbury.|
Habitat and Ecology
|Swartland Silcrete Renosterveld, Swartland Shale Renosterveld|
|Silcrete outcrops in shale renosterveld.|
|More than 90% of shale and silcrete renosterveld within this species' known range has been converted to crop fields, and only small remnants remain. These are densely infested with alien invasive plants, and continue to be degraded due to a lack of fire. Fire is required for regeneration of reseeding species such as Marasmodes oligocephala. In addition, livestock grazing is causing ongoing degradation of small fragments, especially when they are overstocked, as well as facilitating the spread of alien invasive grasses, which are particularly difficult to eradicate.|
Marasmodes oligocephala is a range-restricted and highly localized habitat specialist. Currently, four subpopulations remain on small renosterveld remnants within an area of 7 km². At two of these locations, the species is fairly common, with around 200 plants occurring at each. A third subpopulation is very small, consisting of about 10 plants. The fourth subpopulation was last observed in 2006, and the number of plants was not counted. This subpopulation occurs on a tiny fragment (2 ha), and is unlikely to be large. It is therefore estimated that the population numbers fewer than 500 mature individuals, and continues to decline due to ongoing habitat loss and degradation.
|This species flowers in autumn and is very cryptic and can easily be missed during surveys for Environmental Impact Studies.|
|Magee, A.R., von Staden, L. & Raimondo, D. 2016. Marasmodes oligocephala DC. National Assessment: Red List of South African Plants version 2017.1. Accessed on 2020/01/18|