A biosystematic study of the Jacobaea maritima group (Asteraceae, Senecioneae) in the Central Mediterranean area

The biosystematics of Jacobaea maritima (L.) Pelser & Meijden and four closely related taxa in the Central Mediterranean area has been studied. Nine representative populations of five taxa (J. maritima subsp. maritima, subsp. bicolor, subsp. gibbosa, J. ambigua subsp. ambigua and subsp. nebrodensis) were analysed. Molecular analysis confirms close relationships among taxa (trn LEU and ITS II sequences are identical); ITS I and ISSR analysis, on the other hand, shows some variability. Multivariate PCoA, based on 22 morphological variables, shows a gradient connecting all populations; a rather clear grouping of taxa is obtained, however, when the population from Levanzo is excluded. Finally, a new subspecies, J. maritima subsp. sicula, is proposed.