Five new species of Inocybe, I. iringolkavensis, I. keralensis, I. kuruvensis, I. muthangensis and I. wayanadensis, are described from Kerala state, India, based on morphological and molecular data. All are associated with trees belonging to Dipterocarpaceae. Inocybe iringolkavensis is characterized by nodulose to somewhat stellate basidiospores, 1-4-spored basidia, and caulocystidia restricted to the stipe apex. Inocybe keralensis has a yellowish brown pileus, lamellae with whitish, serrate edges, smooth, ellipsoidal basidiospores and a duplex pileipellis with the superficial hyphae devoid of encrustations and encrusted hyphae beneath. The diagnostic features of I. kuruvensis include a dark brown pileus, stipe with a whitish base and grayish brown, floccose-fibrillose surface, nodulose basidiospores with saddle-shaped projections and faintly encrusted paracystidia with refractive contents. Violet basidiomata with a rimose, hygrophanous pileus, densely pruinose stipe with a marginate-bulbous base, and nodulose basidiospores are the major features of I. muthangensis. Inocybe wayanadensis is characterized by small, whitish basidiomata, a viscid pileus with a rimulose surface, a densely pruinose and fibrillose stipe with a marginate-bulbous base, nodulose basidiospores, thick-walled pleuro- cheilo- and caulocystidia and an ixotrichoderm-type pileipellis. The phylogenetic relationships of these new species are inferred from an analysis of nuc rDNA sequences of the internal transcribed spacers (ITS1-5.8S-ITS2) and the 28S gene. Except I. keralensis, which belongs to the Pseudosperma clade, all other species belong to the Inocybe clade. This study represents the second report of an Inocybe species (I. muthangensis) that combines violet basidiomata with nodulose basidiospores.
Keywords: Basidiomycota; Inocybaceae; phylogeny; systematics; tropical agarics.
© 2016 by The Mycological Society of America.