A taxonomic revision of the Siler montanum group (Apiaceae) in Italy and the Balkan Peninsula

A morphometric-based taxonomic revision of the Siler montanum group (Apiaceae) from Italy and the Balkan Peninsula was carried out. Multivariate and univariate analyses were performed on 47 morphological characters including seven ratios, and based on the study of 328 dried herbarium specimens. According to our results, the characters employed in the study revealed their suitability as key characters for the examined taxa. A taxonomic treatment was presented and a new diagnostic key to the S. montanum group is also provided for Italy and Balkan Peninsula. Ten taxa were recognized within the group, and among them three new subspecies were described: S. montanum subsp. apuanum, S. montanum subsp. corrasianum and S. montanum subsp. ogliastrinum. Furthermore, three new combinations were proposed: S. zernyi subsp. laeve, S. zernyi subsp. ochridanum and S. montanum subsp. stabianum. Six names were lectotypified: Laserpitium garganicum var. balcanicum, L. garganicum var. laeve, L. garganicum var. scabrum, L. siculum var. stabianum, L. siler var. ovalifolium and Ligusticum garganicum. Occurrences were confirmed for Siler zernyi subsp. zernyi in Greece and S. zernyi subsp. laeve in North Macedonia. Occurrences were excluded for S. montanum subsp. garganicum in Greece and North Macedonia and S. montanum subsp. siculum in C and S Italy.