Determining the age of clonal plants: challenges and prospects

Determining the age of genetic individuals in clonal plants is fundamental for understanding their persistence strategies, but is inherently challenging due to the gradual loss of older parts as the clone expands. The first step in age estimation is to assign physically independent individuals (ramets) to genetic individuals (genets) by molecular methods. Once this is established, the size and rate of lateral spread (LS) of the genet can be measured or estimated using morphological traits. More recently, classical or somatic molecular clocks, using genomic data, have been proposed. In this review, we examine the methodological principles and limitations of both morphological and genomic approaches, and propose a conceptual framework that integrates these methods to enable more robust and reliable age estimations of clonal plants.