Genetic and morphological comparisons of a potentially invasive weed (Argemone ochroleuca) from its natural (Mexico) and invaded (South Africa) habitat
Jansen van Vuuren, B
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Morphological and genetic comparisons of a potentially invasive weed (Argemone ochroleuca) from its natural (Mexico) and invaded (South Africa) habitats are presented. Seeds from 14 Mexican and 13 South African populations were germinated and established in controlled conditions. A variety of morphological and genetic attributes were examined to a) determine if invasion success for this species is reflected in attributes such as seed size; germination rate; growth rate, defence etc and b) if the background variation in morphology and genetics is significantly different between the two groups (natural vs invaded range). Compared to natural populations, seeds in invaded populations were significantly less variable in size and germinated more consistently, even when taking into account seasonal variance associated with hemisphere of origin. In addition, adult plants were significantly better defended by thorns, specifically on seed capsules. Genetic data were not yet available at the time of writing.