Taxonomic revision of Eunotia luna var. aequalis f. paucistriata Frenguelli and E. luna var. aequalis f. major Frenguelli: analysis of type material, lectotypification and current taxonomic status

Abstract

The valve morphology of the infraspecific taxa of Eunotia luna reported by J. Frenguelli for the Esteros del Iberá (Argentina) (E. luna var. aequalis, E. luna var. aequalis f. paucistriata and E. luna var. aequalis f. major) were examined to elucidate their taxonomic position. As result of the study with light and electron microscopy, we concluded that E. luna var. aequalis sensu Frenguelli and E. luna var. aequalis f. paucistriata are in fact the extremes of the range of variation of the same taxon, here considered as synonym of Eunotia deficiens. E. luna var. aequalis f. major shows a distinct valve morphology and it is therefore raised to the status of species as Eunotia silviasalae nom. nov. Since Frenguelli did not designate holotypes for E. luna var. aequalis f. paucistriata and E. luna var. aequalis f. major, we designate herein the corresponding lectotypes.