The Asian palm Trachycarpus fortunei has become an invasive neophyte in Central Europe. It is characterised by a complex sexual expression. The knowledge about its genetics is very scant. We aimed at understanding the floral structural mechanisms, characterising its genetic diversity, clarifying the sexual expression strategy, and identifying patterns that could promote its invasiveness. Developmental stages of reproductive organs were studied. The genetic diversity was analysed using microsatellites and SNP markers (populations from Ticino, Lombardy and Piedmont). The genetic sex determination was explored using GWAS analyses. Morpho-anatomical aspects that could promote dispersal were observed. Genetic diversity appears to be related to the colonisation process. Homozygote and heterozygote systems have been found in female and male individuals, respectively. This study allowed a better understanding of its dispersion. The unstable sexual expression may have played a role in promoting its colonisation ability. New management strategies of this species were explored.