Diversity of Volatile Compounds in the Inula candida / I. verbascifolia Group (Asteraceae-Inuleae) and Its Impact on Species Delimitation

The members of the Inula candida / I. verbascifolia group are perennial and chasmophytic plants attributed to four species eleven entities at subspecific or varietal level. They mostly confined Greece. Volatile compounds above-ground flowering parts twenty-three populations covering ten taxonomic were obtained after hydrodistillation analyzed by gas chromatography mass spectrometry (GC-MS). In most cases, total percentage identified constituents reached 89% above. Seventy-two components identified. Oxygenated sesquiterpenes prevailed in subgroup (47.3–71.5%), with epi-α-cadinol present all (13.4–42.7%) but rarely found subgroup. Considerable amounts hydrocarbon aldehydes decanal, undecanal particularly tridecanal (0.5–35.0%, absent) predominately absent Isoalantolactone (12.4–49.5%), only subfloccosa, γ-(Z)-curcumen-12-ol, subsp. limonella (22.6–42.1%), may serve as chemotaxonomic markers. Two different chemotypes can be distinguished within aschersoniana: a trans-muurola-4(14),5-diene-, γ-cadinene-rich chemotype from north-eastern Greece 1-epi-cubenol-, tridecanal-rich central Different statistical algorithms used interpret chemical diversity identify appropriate number clusters for taxa. Cluster analyses indicated that optimum best explain metabolomic variability taxa is two. degree membership each population based on fuzzy k-means algorithm supported aschersoniana samples subgroup, whereas subfloccosa belong any two formed, although it also appears have some unique characteristics.