Interannual and interpopulation variation in Helichrysum stoechas (Asteraceae), a species of disturbed habitats in the Mediterranean region

Abstract

AbstractThis study examines the interpopulation, interannual and individual variation in Helichrysum stoechas L., a perennial species that colonizes disturbed habitats in the Mediterranean region. The phenotypic variation in five populations was studied. Characters such as plant height and volume, numbers of capitula and flowers, weight of achenes and germination parameters were recorded in situ and in the laboratory for the same individuals for two consecutive years. The data were analyzed to examine the differences between populations and years compared to within‐population variation. Results show that the germination rate, the average weight of achenes and the average number of capitula per stem varied considerably from one year to another, independently of population. This year‐to‐year variation suggests that these traits exhibit phenotypic plasticity. The substantial variation in precipitation during the 2 year study may account for the observed temporal variation. There was some weak correlations between the different characters studied within each population. Significant positive correlations were observed between mean achene weight and the total number of achenes produced per plant and with plant size.