Multivariate morphometric analysis and taxa delimitation in two narrow Greek endemics: Astragalus maniaticus and Aethionema saxatile subsp. corinthiacum

Abstract

Astragalus maniaticus and Aethionema saxatile subsp. corinthiacum have vague taxonomic relationships. Astragalus maniaticus was placed in sect. Hypoglottis but shows affinities to A. suberosus subsp. haarbachii of sect. Platyglottis. The Aethionema saxatile complex is an intriguing group due to the wide distribution and morphological variability of its taxa. In order to elucidate the variation patterns of these two taxa and to test their morphological identity, we carried out several multivariate morphometric (stepwise canonical and classificatory) analyses. They revealed that Astragalus maniaticus cannot be distinguished from A. suberosus subsp. haarbachii on morphological grounds. Therefore, it is transferred to sect. Platyglottis and regarded a heterotypic synonym of A. suberosus subsp. haarbachii. The taxonomic interpretation of Aethionema saxatile subsp. corinthiacum necessitated a broad revision of the Ae. saxatile group in Greece and detection of its relations with Ae. rhodopaeum, a Bulgarian endemic. The analyses showed that Ae. saxatile subsp. corinthiacum represents a distinct taxon; likewise, three additional subspecies receive support of similar strength: subsp. creticum, subsp. graecum and subsp. oreophilum. Intermediate forms between subsp. oreophilum and subsp. saxatile were detected in NW Greece. Ae. rhodopaeum is more variable than its original circumscription and is considered as another subspecies of Ae. saxatile.

Keywords:

• Aethionema
• Astragalus
• conservation
• discriminant analysis
• endemics
• Greece
• morphometry
• taxonomic revision

Acknowledgements

The authors wish to thank the curators or keepers of Herbaria ATH, ATHU, B, BM, LD, SO and UPA and in particular Dr A. Asenov and D. Mermygas for offering access to plant collections and/or important assistance with specimen requests. Mr. A. Iliadis accompanied Th.C. in the field. Th. Karamplianis, MSc and Dr C. Radea helped with preparing Figure 1.

Funding

This work was partially supported by the National & Kapodistrian University of Athens Special Account for Research Grants [grant number 11241].