Untangling the Lactifluus clarkeae-Lf. flocktoniae (Russulaceae) species complex in Australasia

The Lactifluus clarkeae complex is a commonly observed, generally brightly coloured, group of mushrooms that are usually associated with Nothofagus or Myrtaceous hosts in Australia and New Zealand. For this study collections labelled as 'Lactarius clarkeae', 'Russula flocktoniae' and 'Lactarius subclarkeae' were examined morphologically and molecularly. Analyses of molecular data showed a high cryptic diversity, with sequences scattered across 11 clades in three subgenera within Lactifluus, and a single collection in Russula. We select epitypes to anchor the currently accepted concepts of Lf. clarkeae s.str. and Lf. flocktoniae s.str. The name Lf. subclarkeae could not be applied to any of the collections examined, as none had a lamprotrichoderm pileipellis. Lactifluus clarkeae var. aurantioruber is raised to species level, and six new species are described, three in subg. Lactifluus: Lf. jetiae, Lf. pagodicystidiatus, and Lf. rugulostipitatus, and three in subg. Gymnocarpi: Lf. albens, Lf. psammo philus, and Lf. pseudoflocktoniae. A new collection of Lf. russulisporus provides a significant range extension for the species. Untangling this complex will enable better identification of species and increase understanding of diversity and specific habitat associations of macrofungi.