Morphometry of the labellum and the lateral petal in Dactylorhiza romana (Sebast.) Soo

This study aimed to compare the labellum and lateral petal morphology of the dimorphic specimens of Dactylorhiza romana with pink and white flowers collected in Türkiye, using classical and geometric morphometric methods. In classical morphometric analyses, characteristics such as area, perimeter, aspect ratio, circularity, and solidity of the labellum and lateral petal structures were examined, and intergroup differences were evaluated using variance analysis (ANOVA) and discriminant analysis. In the geometric morphometric method, shape analyses were performed through homologous landmarks; Procrustes analysis, principal component analysis (PCA), discriminant analysis, and regression analysis were conducted. The findings revealed that the samples from the Samsun locality were distinctly separated from the Çanakkale and Bolu groups, while Bolu exhibited a transitional region characteristic. Additionally, it was determined that the examined floral structures were effective in distinguishing between localities; however, color variations did not have a significant effect on morphological differences. Among the floral characters, especially morphometric traits such as circularity and solidity played a significant role in the differentiation between localities.