Rare sporophyte found in Europe for Herbertus sendtneri with a range expansion to Africa and Malesia

Abstract

The sporophytes of the genus Herbertus are rare or completely absent in some areas. The first discovery of the sporophyte of Herbertus in Europe, on H. sendtneri from a herbarium specimen collected in Austria in 1851, is reported here. We report that finely papillose spores characterize Herbertus species which have originated in the Northern Hemisphere, whereas the spores of the species which have originated in the Southern Hemisphere are tuberculate or shortly spinulose. Based on morphological studies of over 600 herbarium specimens of Herbertus, supported by previously published molecular phylogenetic studies, H. armitanus and H. circinatus are new synonyms of H. sendtneri. It is distinct from other Northern Hemisphere species by its coarsely toothed leaf base, despite large variation in leaf size and shape, and leaf apex cilia. The range of H. sendtneri is now extended to east Africa (Tanzania) and Malesia (Papua New Guinea and the Solomon Islands).