Interspecific competition with the American Xanthium orientale L. as a possible cause of the decline of the Old-World X. stumarium L
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Xanthium is represented in Europe by three species complexes: X. strumarium L., X. orientale L., and X. spinosum L. The former two complexes are similar, in both morphology and ecological requirements. Xanthium strumarium is native to the Old World, whereas X.... ...
