<i>Spongispora temasekensis</i>, a new boletoid genus and species from Singapore

<p>Dipterocarp forests are a typical and widespread type of vegetation in tropical lowlands of southeast Asia that harbor a high diversity of ectomycorrhizal fungi, including boletes. Based on molecular and morphological characters, a unique bolete found in Singapore associated with the dipterocarp <i>Hopea odorata</i> was proven to represent a new species in the proposed new genus <i>Spongispora</i>. Phylogenetic analyses of five loci indicate that <i>Spongispora</i> is nested in the subfamily Leccinoideae of the Boletaceae, most closely related to an inclusive clade of <i>Leccinum, Leccinellum, Octaviania, Rossbeevera</i>, and <i>Turmalinea</i>. However, genetic distances between <i>Spongispora</i> and genera in Leccinoideae are mostly higher than that between any two known genera in this subfamily, which supports the proposal of a new genus. <i>Spongispora temasekensis</i> is characterized by a whitish to pale yellow hymenophore that stains brown where injured, coarsely reticulate stipe, interwoven trichodermial pileipellis, and broadly elliptical to ovoid basidiospores with sponge-like ornamentation perforated by irregular clefts, cracks, and warts under scanning electron microscopy. Morphological descriptions, illustrations, and comparisons with allied taxa are made, and a key to the genera of the subfamily Leccinoideae is provided.</p>