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   Oxalis pes-caprae (herb)
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         Interim profile, incomplete information
    Taxonomic name: Oxalis pes-caprae L.
    Synonyms: Bolboxalis cernua (Thunb.) Small, Oxalis cernua Thunb., Oxalis libica Viv., Oxalis pleniflora Lanfranco
    Common names: African woodsorrel, Bermuda buttercup, buttercup oxalis, Englishweed, sour sorrel (South Africa), sourgrass, soursob, yellow sorrel
    Organism type: herb
    Oxalis pes-caprae is a short, perennial herb that is native to southern Africa. It mainly reproduces vegetatively via bulbs, and can form large clonal colonies. Colonies flower synchronously, with distinctive bright yellow flowers that are large and cup-shaped. It is commonly found growing in agricultural areas, cultivated areas, fields, disturbed/ruderal zones, gardens, wasteland, riparian zones, dunes and scrubland.
    Occurs in:
    agricultural areas, coastland, planted forests, range/grasslands, riparian zones, ruderal/disturbed, scrub/shrublands, urban areas
    General impacts
    Oxalis pes-caprae can suppress other ruderal weedy plants, including native species, smothering them and leading to a reduction in biodiversity. The leaves are toxic and can pose a danger to livestock if growing in fields or grassy areas. O. pes-caprae growing in agricultural areas can also be a pest during harvesting and decreasing yield. The presence of O. pes-caprae has been shown to decrease cereal ssed germinability by up to 63%. (EPPO 2006a; Lambdon 2006; Marshall 1987; Petsikos et al. 2007).
    Oxalis pes-caprae is listed as an invasive species by the European & Mediterranean Plant Protection Organisation (EPPO) (EPPO 2006a).
    Geographical range
    Native range: South Africa
    Known introduced range: Mediterranean Basin (Lambdon, 2006); Australia, New Zealand, United States (California, Arizona and Florida), parts of Asia (USDA-ARS 2008; USDA-NRCS 2010); Bermuda and Gibralter (Varnham, 2006)
    Management information
    Mechanical control: Some livestock (e.g. pigs, turkeys) are known to graze on the bulbs of Oxalis pes-caprae, and this can be used as a control measure. (Lambdon 2006).

    Chemical control: Pre-emergence herbicides have been found to be effective against O. pes-caprae, particularly those containing glyphosphate or sulfonyl urea. O. pes-caprae is known to be resistant against dinitroaline-based herbicides. (Lambdon 2006).

    Oxalis pes-caprae reproduces vegetatively, via bulbs. The mechanism by which this occurs is an underground movement combination of shoot elongation and root contraction. This results in a very effective method of bulb dispersal. However O. pes-caprae is also very dependent on human and animal-mediated dispersal into new areas. (EPPO 2006b; Pütz 1994).
    Compiled by: IUCN SSC Invasive Species Specialist Group (ISSG) with support from the Overseas Territories Environmental Programme (OTEP) project XOT603, a joint project with the Cayman Islands Government - Department of Environment
    Last Modified: Tuesday, 8 June 2010

ISSG Landcare Research NBII IUCN University of Auckland