Re-assessment of type material of Plagiothecium novae-seelandiae Broth. and descriptions of four new Plagiothecium taxa (Bryophyta, Plagiotheciaceae) from Australasia

Abstract

A re-examination of the original collection of Plagiothecium novae-seelandiae described by Brotherus in 1916 indicated that this material is not homogeneous. Re-examination of the diagnosis of this species and morphological analysis supports that two separate taxa should be distinguished – Plagiothecium novae-seelandiae var. novae-seelandiae and P. novae-seelandiae var. brotheri var. nov. Also, comparisons with the original collection of Hypnum lamprostachys (= P. lamprostachys) showed differences, which supported their treatment as separate taxa. Revision of the genus Plagiothecium from Australasia (CANB, CHR, HO, MEL, WELT) and types of other species described from this part of the world (P. funale and P. lucidum) supported by the study of their diagnoses, qualitative and quantitative characteristics as well as mathematical analyses (PCA, HCA) allowed the division of the examined material into six separate groups – six separate taxa. Thereby, three distinct taxa are proposed – P. cordatum sp. nov., P. semimortuum sp. nov., and P. semimortuum var. macquariense var. nov. All taxa mentioned above are described in detail, their current known distribution and ecological preferences are also included. In addition, images illustrating their most important taxonomic features, as well as an original key to distinguish individual taxa are presented.