XVI International Botanical Congess

Based on historic, cytological, bibliographic references, as also on personal observations in the field and herbarium specimens, this investigation concludes the common prickly-pear BOpuntia ficus-indica- is an horticultural plant domesticated from near 9000 years from now, for the ancient mexicans. At the domestication the species adquires a higer ploidia and retrobreding with wild plants have been result in a general increment of the chromosome number (6x or 8 X). The present wild plants at Mexico have been described as O. streptacantha and O. megacantha. After the discovery of America this species have been introduced at Spain and later around the mediteranean see, mainly for navegators who used it as vegetable. At the new places, new specimens reproduced expontaneously or not, shows relictual characters (biger spines and others) and also in different countries botanist described them as new species. As the non spiny and the spiny specimens are considered only forms of O. ficus-indica, for nomenclatural reasons the name O. ficus.indica f. amyclaea (Tenore) Schelle must be used for the spiny plants.