New names and new combinations for hypnalean mosses

• Published in: The Bryologist
• Main Author: Justin T. Wynns
• Format: Text
• Language: English
• Published: The American Bryological and Lichenological Society 2020
• Subjects: Austral; Kerguelen; Kerguelen Islands; Antarc*; Tierra del Fuego
• Online Access: https://doi.org/10.1639/0007-2745-122.4.633

Several nomenclatural changes in the Hypnales are proposed in order to purify the circumscription of Pseudotaxiphyllum and Taxiphyllum. Three species of Pseudotaxiphyllum (P. falcifolium, P. homomallifolium and P. richardsii) do not fit well in any current genus, or belong to distinctive subgeneric lineages, which necessitates the description of novel taxa (Margrethypnum gen. nov., Redfearnia gen. nov., and Taxiphyllum subgen. Parataxiphyllum subgen. nov.). A fourth species, Pseudotaxiphyllum distichaceum [≡ Stereodon distichaceus], is transferred to Longiella, leaving only species that produce branch-like gemmae in Pseudotaxiphyllum. Five species of Taxiphyllum are transferred to other genera: T. fluitans and T. gabonense to Ectropothecium, T. laevifolium [≡ E. laevifolium] to Phyllodon, T. ligulaefolium [≡ Glossadelphus ligulaefolius] to Mittenothamnium, and T. torrentium [≡ Amblystegium torrentium] to Bryocrumia. A 50-taxon ITS-based phylogeny is included for illustrative purposes. Plagiothecium sect. Stansvikia is established to accommodate a group of medium-sized to large, glossy, autoicous species with an austral oceanic distribution. Included taxa are P. subantarcticum sp. nov. [= P. Donianum sensu Mitten 1869] from Tierra del Fuego, P. falklandicum, P. georgicoantarcticum, P. georgicoantarcticum var. antarcticum comb. nov. [≡ Hypnum antarcticum] from the Kerguelen Islands, and P. novae-seelandiae. Phylogenetically, sect. Stansvikia belongs to the core of the genus and is related to both sect. Plagiothecium and sect. Leptophyllum (P. lucidum s.l.).