|Scientific Name:||Oldenlandia adscensionis (DC.) Cronk|
Hedyotis adscensionis DC.
Oldenlandia adscenionis (DC.) Cronk [orth. error]
|Red List Category & Criteria:||Extinct ver 3.1|
|Assessor(s):||Lambdon, P.W., Stroud, S., Gray, A., Niissalo, M. & Renshaw, O.|
|Reviewer(s):||Scott, J.A. & Hilton-Taylor, C.|
Oldenlandia adscensionis was already listed as Extinct in 1997 and 2003. Despite regular searches of suitable areas since then, no further plants have been located.
|Previously published Red List assessments:|
|Range Description:||A little known species which was already rare by the time botanical recording began on Ascension Island, Saint Helena. Most reports suggest that it occurred at mid- to moderately high altitudes on Green Mountain, but may have originally extended more widely into the surrounding, arid, lowland zones. The last recorded locality was in a dry gully below the southern slopes of Sister’s Peak, presumably between 200 and 250 m in altitude.|
Regionally extinct:Saint Helena, Ascension and Tristan da Cunha (Ascension)
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||This species is extinct.|
|Habitat and Ecology:||Although reports of tree-sized plants on Ascension were made by William Dampier prior to human settlement, later reports suggest that the last surviving individuals of O. adscensionis were mostly small shrubs, perhaps persisting for a few decades at most, and regular recruitment would therefore be necessary for survival. Although it is possible that a small population remains on an inaccessible rock face, it seems increasingly unlikely that it would continue to evade attention. Perhaps the greatest possibility of survival is via the germination of a dormant seed. As a species capable of surviving on arid slopes with infrequent rains, it seems likely that the species was adapted to at least short periods of dormancy although there is no information on the persistence of the seed bank. Detection of an isolated seedling remains highly improbable, and the propagules would be extremely vulnerable to grazing by sheep or rabbits within the first few months.|
|Use and Trade:||There is no known form of utilization for this species.|
|Major Threat(s):||Goats were introduced to Ascension in the years following its discovery. Later, sheep, rabbits and rats followed. All have probably had a devastating impact on the native flora through grazing, as prior to this the island had no natural large herbivores. Subsequently, invasion by numerous non-native plant species, which now constitute a very high proportion of the total vegetation cover, has resulted in strong habitat modification and lead to massive competition for the dwindling natives and endemics.|
Green Mountain was declared a National Park in 1996. Due to the low population density on Ascension, there is little human interference in the area and further legislation is not a priority.
The Island’s Conservation Department conduct an annual survey of endemic plant numbers in which key endemic plant habitats are searched for. In addition, many remote areas may be visited as part of routine maintenance activities. These efforts have failed to locate any populations thus far.
|Citation:||Lambdon, P.W., Stroud, S., Gray, A., Niissalo, M. & Renshaw, O. 2012. Oldenlandia adscensionis. The IUCN Red List of Threatened Species 2012: e.T43923A2990410.Downloaded on 21 November 2017.|
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