A New Lichenized Fungus, Psoroglaena humidosilvae, from a Forested Wetland of Korea, with a Taxonomic Key to the Species of Psoroglaena

Abstract

Psoroglaena humidosilvae Lee is described as a new lichen species from a wetland forest in South Korea. The new species is distinct from P. stigonemoides (Orange) Henssen by little projections locally present on the thallus; smaller, paler, and globose perithecia; smaller asci; and smaller ascospores generally 3-septate. Molecular analyses employing internal transcribed spacer (ITS), mitochondrial small subunit (mtSSU), and nuclear large subunit ribosomal RNA (LSU) sequences strongly support P. humidosilvae as a nonidentical species in the genus Psoroglaena. A surrogate key is provided to assist in the identification of all 22 species of Psoroglaena.

Keywords: Verrucariaceae; biodiversity; corticolous; phylogeny; taxonomy.

Figure 1

Specific collection site for the new species Psoroglaena humidosilvae (black star mark). The small swamp is located below a forest road and comprised mainly of Salix koreensis Andersson, Alnus incana (L.) Moench subsp. hirsuta (Turcz. ex Spach) Á.Löve and D.Löve, Fraxinus sieboldiana Blume and Weigela subsessilis (Nakai) L.H.Bailey. Lichens were detected on the barks of Salix koreensis and Alnus incana subsp. hirsuta.

Figure 2

Phylogenetic relationships among available species in the genus Psoroglaena based on a maximum likelihood analysis of the dataset of ITS sequences. The tree was rooted with the sequences of the genus Placidium based on Muggia et al. [9]. Maximum likelihood bootstrap values ≥70% and posterior probabilities ≥ 95% are shown above internal branches. Branches with bootstrap values ≥90% are shown as fatty lines. The new species, P. humidosilvae, is presented in bold as their DNA sequences were produced from this study. All species names are followed by the GenBank accession numbers.

Figure 3

Phylogenetic relationships among available species in the genus Psoroglaena based on a maximum likelihood analysis of the dataset of mtSSU sequences. The tree was rooted with the sequences of the genus Placidium based on Muggia et al. [9]. Maximum likelihood bootstrap values ≥70% and posterior probabilities ≥95% are shown above internal branches. Branches with bootstrap values ≥90% are shown as fatty lines. The new species, P. humidosilvae, is presented in bold as their DNA sequences were produced from this study. All species names are followed by the GenBank accession numbers.

Figure 4

Phylogenetic relationships among available species in the genus Psoroglaena based on a maximum likelihood analysis of the dataset of LSU sequences. The tree was rooted with the sequences of the genus Placidium based on Muggia et al. [9]. Maximum likelihood bootstrap values ≥70% and posterior probabilities ≥95% are shown above internal branches. Branches with bootstrap values ≥90% are shown as fatty lines. The new species, P. humidosilvae, is presented in bold as their DNA sequences were produced from this study. All species names are followed by the GenBank accession numbers.

Figure 5

Psoroglaena humidosilvae (KBA-L-0002007, holotype for (A–C), (F–N); KBA-L-0002005, paratype for (D–E) in morphology. (A–C) Habitus and apothecia on bark of Salix koreensis. A minute filament (red arrow) shown in (C). (D–E) Appressed filaments (papillae) as minute projections on thallus. (F) Globose perithecia without involucrellum. (G) The 5- to 6-layered excipulum. (H) Ostiolar region with periphyses. (I–M) Asci clavate to cylindrical. (N) Ascospores generally 3-septate. Blue colors stained in Lactophenol cotton blue in (L–N). Scale bars: (A) = 2 mm, (B) = 1 mm, (C) = 500 μm, (D) = 50 μm, (E,H–N) = 10 μm, (F) = 100 μm, (G) = 20 μm.