A generic revision of the Warnstorfia-Calliergon group

Abstract The genera of the Warnstorfia-Calliergon group are revised taxonomically. The following genera are recognized: (1) Calliergon (Sull.) Kindb., with C. cordifolium (Hedw.) Kindb., C. giganteum (Schimp.) Kindb., C. megalophyllum Mik. and C. richardsonii (Mitt.) Kindb.; (2) Loeskypnum Paul, with L. badium (Hartm.) Paul in Europe and L. wickesii (Grout) Tuom. occurring outside Europe only; (3) Straminergon Hedenas, gen. nov., with S. stramineum (Brid.) Hedenas, comb. nov.; (4) Warnstorjia Loeske, with W. exannulata (B., S. & G.) Loeske, W. fluitans (Hedw.) Loeske, W. procera (Ren. & H. Arn.) Tuom., W. pseudostraminea (C. Mull.) Tuom. & T. Kop., W. sarmentosa (Wahlenb.) Hedenas, comb. nov., W. trichophylla (Warnst.) Tuom. & T. Kop. and W. tundrae (H. Arn.) Loeske in northern Europe and W. luipichensis (Williams) Hedenas, comb. nov., and W. pseudo-sarmentosa (Card. & Ther.) Tuom. & T. Kop. occurring outside Europe only. Type material of many other taxa was studied and their generic placement considered,...