Comparative morphometry as a diagnostic tool applied to species delimitation in the genus Gastridium P. Beauv. (Poaceae)

A comparative study of the closely related species of the genus Gastridium (Poaceae, Tribe: Poeae, Subtribe: Agrostidinae), G. ventricosum, G. phleoides, and G. scabrum was assessed based on a critical examination of both fresh and dried specimens, including relevant material, and a morphometric analysis of herbarium specimens collected in Italy. The study aimed to provide new diagnostic tools to improve the taxonomy of the genus and confirm species delimitation. Thus, variation in floral morphology in the three species was further explored using seven quantitative and ten qualitative characters measured on 318 spikelets, both awned and unawned. Statistical methods, including principal components analysis (PCA) and non‐metric multidimensional scaling (NMDS), were used. Numerical analyses showed a general distinctness of spikelets and florets, consistent with the three studied species, and revealed among and within species variation patterns in between‐ both spikelet types. Accordingly, ...