Varronia rupicola 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Plantae Tracheophyta Magnoliopsida Lamiales Boraginaceae

Scientific Name: Varronia rupicola (Urb.) Britton
Cordia rupicola Urb.
Taxonomic Source(s): Miller, J.S. and Gottschaling. 2007. Generic classification in the Cordiaceae (Boraginales): resurrection of the genus Varronia P. Br. Taxon 56(1): 163-169.
Taxonomic Notes: Molecular, morphological and palynological data all support the recognition of Varronia as a distinct genus from Cordia (Miller and Gottschaling 2007). Hence this species has been transferred from Cordia to Varronia.

Assessment Information [top]

Red List Category & Criteria: Critically Endangered B1ab(ii,iii,v)+2ab(ii,iii,v) ver 3.1
Year Published: 2003
Date Assessed: 2003-05-01
Needs updating
Assessor(s): Clubbe, C. & Pollard, B. (RBG, Kew), Smith-Abbott, J., Walker, R. & Woodfield, N. (BVI National Parks Trust)
Reviewer(s): Maunder, M. & Strahm, W. (SSC Plant Conservation Committee)
Varronia rupicola is a small woody shrub, originally described as endemic to Puerto Rico (Britton and Wilson 1925). It was known from small subpopulations in Puerto Rico (three sites in the dry southwestern Guárnica region of PR) and Anegada and listed as Endangered in 1997 Red List (Walter and Gillett 1998). The Puerto Rico subpopulations could not be relocated in 1992 and it is thought to be extirpated on Puerto Rico (Kraus 1999, pers. comm.). We have treated the Anegada subpopulation as the total remaining global distribution. The area of Anegada is 38 km², of which approximately one third is water in the form of salt ponds. Therefore the extent of occurrence for Varronia rupicola is approx. 25 km². Fieldwork has determined that V. rupicola is found only in the western half of the island where it is locally abundant on both limestone and within the sand dune system, showing a slight preference for limestone. Its area of occupancy has been estimated as < 5 km². Because of the small size of the island and the known distribution of this species we have treated this as one location. The island of Anegada is under extreme pressure for residential and tourism development. This has already resulted in documented habitat fragmentation and loss leading to a decline in the quality of the habitat for this species. All the available information indicates that this will accelerate in the next few years. This will result in a continued decline in the area of occupancy, quality of the habitat and a reduction in the number of mature individuals.
Previously published Red List assessments:

Geographic Range [top]

Range Description:Anegada, British Virgin Islands. Extent of occurrence: 25 km², area of occupancy: <5 km². Extirpated in Guánica, Puerto Rico. Population size unknown, but field observations indicate it to be locally common on the western half of the island. Fieldwork has not located it in the eastern half of the island (east of the airport and the Settlement), despite the occurrence of apparently suitable habitat.
Countries occurrence:
Virgin Islands, British
Regionally extinct:
Puerto Rico
Additional data:
Range Map:Click here to open the map viewer and explore range.

Population [top]

Current Population Trend:Unknown
Additional data:

Habitat and Ecology [top]

Habitat and Ecology:Fieldwork indicates a preference for limestone substrates and it occurred in 69% of plots in open limestone pavement and 60% of plots in the limestone cays. Fairly widespread also in sand dune habitats where it was found in 25% of plots (based on 104, 20x20 m plots assessed). No study of breeding biology undertaken, but this species appears to flower and set fruit regularly and in abundance.

Threats [top]

Major Threat(s): Anegada is under severe development pressure resulting in both loss of habitat to residential and tourism infrastructure, and further fragmentation due to upgrading and construction of new roads. Loose livestock (cattle, goats, donkeys) roam the island and impact at the habitat (trampling) and species level (grazing). Invasive species may be a problem with increasing habitat fragmentation. The Settlement (Anegada’s only town) has lots of known invasives, three of which have been observed moving into natural habitats – Casuarina equisetifolia (also found along several western dunes), Cryptostegia madagascariensis and Bryophyllum pinnatum. Fire may be a problem in the future – increasing use of fire to clear land. Highest point of Anegada is approx. 10 m above sea level. Most of the preferred habitat is <3 m above sea level and so global climate change will reduce quality and area of habitat available to V. rupicola. Natural disasters are a current and on-going threat e.g., hurricanes, coastal inundation and earthquakes.

Conservation Actions [top]

Conservation Actions: A small proportion of the preferred habitat (limestone) lies within a Ramsar site (declared 1999) and national legislation is currently being prepared to declare this a Protected Area. Protected Wildlife legislation is currently being revised and consideration being given to including named endemic/ threatened species of flora and fauna within this Schedule.

Citation: Clubbe, C. & Pollard, B. (RBG, Kew), Smith-Abbott, J., Walker, R. & Woodfield, N. (BVI National Parks Trust). 2003. Varronia rupicola. The IUCN Red List of Threatened Species 2003: e.T43896A91321755. . Downloaded on 18 June 2018.
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