摘要: Co-occurring plants communicate chemically with each other, sometimes leading to changes in species distributions and the composition of communities. In the context of the invasive success of alien plant species, interspecies communication requires an ecological perspective, ie an understanding of the natural limits of the communication process. Many studies link allelochemical processes to the establishment and invasiveness of alien plants based on phytotoxicity studies that are unlikely to be replicated in nature. In this context, we suggest revising the definition of chemical communication and framing it as ‘allelopathy', with a focus on studying the effects of phytochemicals at reasonably natural concentrations, or ‘phytotoxicity', showing toxicity but without a clear understanding of the natural concentrations of the chemicals, or the ‘Novel Weapons Hypothesis'(NWH), to place allelopathy within a clear biogeographical context. For this we use Australian Acacia species ('wattles') as an example. We reviewed the literature on chemical communication of wattles and classified the processes studied in a natural context to identify the contribution of the NWH to the invasive success of wattle species around the world. Novel weapons play a role in the invasion process if allelochemicals that are released naturally by invasive species have weaker effects on their co-evolved neighbours (from the native range) than on resident plants in non-native ranges. Although such a biogeographic perspective is the most appropriate for studying the new relationships established by invasive species with resident species, it has not been applied to understand wattle …