Morphology and multigene phylogeny revealed four new species of Geastrum (Geastrales, Basidiomycota) from China

In the present study, four new species, <i>Geastrumartocarpicola</i>, <i>G.fibulatum</i>, <i>G.sinense</i> and <i>G.trachelium</i> collected from China, are proposed based on a combination of morphological characteristics and molecular evidence. <i>Geastrumartocarpicola</i> is characterized by shallowly saccate to deep saccate exoperidium, bubble-shaped to flask shaped basidia, spherical basidiospores. <i>G.fibulatum</i> is characterized by shallowly saccate to deep saccate exoperidium, spherical basidiospores, generative hyphae with clamp connections in the mycelium layer. <i>G.sinense</i> has arched exoperidium, long stipe expanded basidiomata, and spherical basidiospores. <i>G.trachelium</i> has deep saccate exoperidium, flask-shaped basidia, and spherical basidiospores. Sequences of the internal transcribed spacers (ITS), large subunit (nrLSU), the largest subunit of ribosomal polymerase II (RPB1), and subunit 6 of ATP synthase (ATP6) of the nuclear ribosomal DNA (rDNA) markers of the studied samples were generated, and the phylogenetic analyses were performed with maximum likelihood, maximum parsimony and Bayesian inference methods. The results showed that our collection clustered within <i>Geastrum</i> but distinctly from the others. Full morphological descriptions, illustrations, and phylogenetic analyses results for the four new species are provided. In addition, <i>G.sanglinense</i> is treated as a synonym of <i>beijingense</i>.