|Scientific Name:||Beta patula|
Beta vulgaris L. subspecies patula (Aiton) Ford-Lloyd & J. T. Williams
|Taxonomic Notes:||Beta patula Aiton is a primary wild relative of cultivated beets, B. vulgaris L. ssp. vulgaris (leaf, garden, fodder and sugar beet groups) (classified in Beta section Beta). B. patula was given specific rank in a reclassification of the genus by Letschert (1993) and later Lange et al. (1999) based on its distinctive morphology and the fact that it is confined to two small islets off Madeira (Pinheiro de Carvalho 2010). Ford-Lloyd (2005) gives a detailed review of the taxonomy of the genus Beta. Although further changes have been made to the classification of the Beta gene pool since this publication, this has not changed the specific status of B. patula in Section Beta.|
|Red List Category & Criteria:||Critically Endangered B1ab(iii,iv)+2ab(iii,iv) ver 3.1|
|Assessor/s:||Carvalho, M., Frese, L., Duarte, M.C., Magos Brehm, J., Tavares, M., Santos Guerra, A. & Draper, D.|
|Reviewer/s:||Nieto, A., Kell, S.P. & Ford-Lloyd, B.|
Beta patula is assessed as Critically Endangered because its extent of occurrence (EOO) is approximately 70 km² and its area of occupancy (AOO) is less than 10 km²; its distribution is severely fragmented and there is continuing decline in the extent and quality of its habitat. Although this species occurs in a protected area, it is threatened by invasive alien species, grazing pressure and an increase in the seagull population. There is therefore a need for the development and implementation of a species action plan as special site management is needed.
It would also qualify for Vulnerable D2 due to the very restricted AOO, coupled with the threats at these sites.
|Range Description:||Beta patula is endemic to two islets in the Madeira archipielago, Portugal: Ilhéu do Desembarcadouro in the region of Ponta de São Lourenço in the eastern part of mainland Madeira, and Ilhéu Chão in the Desertas Islands to the southwest of mainland Madeira—both small, uninhabited islets. Ilhéu do Desembarcadouro covers an area of 1.8 km², while Ilhéu Chão covers an area of approximately 0.5 km². On Ilhéu do Desembarcadouro, wild beets show a patchy distribution pattern. B. patula has been recorded at six sites on the islet and shares the habitat with B. vulgaris ssp. maritima and Patellifolia procumbens at five of these sites. On Ilhéu Chão, B. patula is found only at one site where it grows alongside B. vulgaris ssp. maritima and Patellifolia procumbens (Frese and Carvalho in prep.). The extent of occurrence (EOO) is approximately 70 km² and the area of occupancy (AOO) is less than 10 km².|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Four hundred individuals were counted at the single site on Ilhéu Chão in 2009. The total population of Ilhéu do Desembarcadouro is estimated to be 2,500 individuals across six sites, with counts per site ranging from three to 223 (M. Carvalho pers. comm. 2010). This is a biennial species and the number of mature individuals fluctuates.|
|Habitat and Ecology:||B. patula grows in dry and rocky localities by the sea coast. It is a partially inbreeding, self-pollinated hermaphrodite (Frese 2005).|
The main site is threatened by invasive alien species and the increasing presence of seagulls. According to the Museum National d'Histoire Naturelle/European Topic Centre on Biological Diversity and Conservatoire Botanique National de Brest (2006), threats to this species also include tourism and recreation, and grazing by introduced animals—particularly rabbits; the authors also note that Ponta do Sao Lourenço is heavily invaded by exotic species. However, as the sites are protected and not easily accessible, tourism and recreation are not serious threats (M. Carvalho pers. comm. 2010).
B. patula is listed in Annex II of the EU Habitats Directive and the genus Beta is listed in Annex I of the International Treaty on Plant Genetic Resources for Food and Agriculture.The islands on which the species occurs are protected by the Parque Natural da Madeira, which is designated as a Special Area of Conservation (SAC) and Special Protected Area (SPA) under the Birds and Habitats Directives. The sites require management to protect this species and ongoing population and habitat monitoring is needed. The development and implementation of a species action plan is recommended.
The International Data Base for Beta (IDBB 2010) reports a number of accessions of which 10 very likely exist as viable seed samples in the following holdings: IPK Genebank, Germany (five), collection of the University of Birmingham, UK (one), Polish Genebank Plant Breeding and Acclimatization Institute (IHAR), Bydgoszcz, Poland (one), National Plant Germplasm System (NPGS), USA (three). As is it not known whether any of these accessions were collected after 1954 (Coons 1954), all accessions may descend from a single seed source exchanged between genebanks.
More recently, seed samples have been collected from all known sites and are stored in the ISOPlexis Genebank at the University of Madeira, Funchal. Four accessions were collected from Ilheu Chão in 2008 and 2009 and 12 from Ilheu do Desembarcadouro between 2007 and 2009. The sampling strategy employed aimed to collect representative diversity by collecting seed from specimens that compose neighbour's patches at each locality.
|Citation:||Carvalho, M., Frese, L., Duarte, M.C., Magos Brehm, J., Tavares, M., Santos Guerra, A. & Draper, D. 2011. Beta patula. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 24 May 2013.|
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