Ants are the main group among invertebrates to disperse the seeds and fruits of plants. Diaspores with morphological adaptations to ant transport are called 'myrmecochorous' (Sernander, 1906). These adaptations are usually a variously shaped lipid-rich appendage called an 'elaiosome' (elaion = oil, soma = body). In some cases (e.g. Puschkinia, Ornithogalum; see Bresinsky, 1963) only a sarcotesta consisting of a layer of lipid-rich cells is provided. Elaiosomes are used as food by ants and this results in the transport of the diaspores to ant nests where the nutritive tissue is eaten. The diaspores themselves are then usually abandoned, intact and viable, either in the nest or outside the nest on waste piles, or close to the ant midden. The attractiveness of elaiosomes for ants has already been experimentally demonstrated by Sernander (1906), and his monograph on Central European and Mediterranean ant-dispersed plants (he recorded approximately 150 species) is still the most comprehensive work for this region. Myrmecochory is fairly common in eastern North America and Europe (e.g. Beattie et al., 1979), and in Mediterranean climate regions of Australia (Berg, 1975) and southern Africa (Milewski and Bond, 1982). According to Beattie and Hughes (2002) myrmecochory is known in more than 80 plant families involving over 3000 species worldwide.
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