Feverfew (Tanacetum parthenium (L.) Sch.Bip), belonging to the family Asteraceae, is a valuable medicinal plant containing effective anti-cancer compounds. The current study was conducted to investigate the diversity of feverfew ecotypes. Ecotypes were collected from different geographical areas of Iran in 2016 and 2017. The experiment was conducted in a completely randomized design with four replications. The analysis of variance showed significant phenotypic differences among the studied ecotypes. The plant height ranged from 55.75 to 124.50 cm and shoot and capitule diameters varied from 3.81 to 8.18 and 7.51 to 15.42 mm, respectively. The aerial biomass weight ranged from 36.62 to 136.40 g, root weight ranged from 9.81 to 36.65 g, and total biomass ranged from 46.44 to 173.05 g. In addition, flower weight varied from 3.46 to 6.21 g, while flower yield ranged from 1.48 to 13.90 g per plant. The obtained results regarding the phenotypic correlation demonstrated that plant height had the highest positive correlation with functional traits. Furthermore, the aerial biomass weight was positively correlated with flower weight, flower number, and flower yield, suggesting that vegetative growth had a positive correlation with reproductive growth. In general, tall plants produced more flowers. We also found some correlations between the geographical distances of ecotypes and phenotypic diversity. The dendrogram obtained based on the measured traits revealed that the classification of ecotypes in close groups can show their kinship and genetic relationships between them.
