Konstantinova, N.A., A.A. Vilnet & Y.S. Mamontov. 2025. Molecular phylogenetic study of the genus Isopaches with description of a new species from South America

Arctoa (2025) 34: 152–164

doi: 10.15298/arctoa.34.12

This is the first molecular phylogenetic study of the genus Isopaches based on a large set of specimens from numerous remote regions of Eurasia and North America. Along with three previously known species, it includes a new species from South America – I. valdiviensis. The latter is formally diagnosed, illustrated, and compared to similar taxa, including another southern hemisphere species, I. pumicicola. We have shown that the genus Isopaches is a group of closely related and slightly divergent taxa and revealed a possible hybrid relation between I. bicrenatus and I. alboviridis. The main morphological differences of the species including sex allocation, leaf width/length ratio, shape of gemmae etc., are discussed. Overlap in some of these characters in different species is shown. A key to all species of the genus is provided.