Xylodon pseudolanatus Nakasone, Yurchenko & Riebesehl

Riebesehl, Janett, Yurchenko, Eugene, Nakasone, Karen K. & Langer, Ewald, 2019, Phylogenetic and morphological studies in Xylodon (Hymenochaetales, Basidiomycota) with the addition of four new species, MycoKeys 47, pp. 97-137 : 97

Xylodon pseudolanatus Nakasone, Yurchenko & Riebesehl sp. nov. Figs 3d, 8

Holotype.

BELIZE: Cayo District, Mountain Pine Ridge, on corticated hardwood branch, leg. K.K. Nakasone, 24 Nov 2001 (CFMR FP-150922; isotypes in KAS and MSK; ex-type culture CFMR FP-150922-sp; ex-type ITS sequence MH880220; ex-type 28S sequence MH884909).

Description.

Basidiomata effused, membranaceous, cream-coloured, 1-6 cm in extent, odontioid with conical aculei 50-120 μm long and 25-65 μm diam. at base, 8-14 aculei/mm. Subiculum between aculei very loose, minutely porulose, 100-150 μm thick. Margin pale cream-coloured, abrupt or diffuse, up to 2 μm wide. Hyphal system monomitic, hyphae clamped at all primary septa, colourless. Subicular hyphae little branched, mostly thick-walled, 2.5-4 μm diam., smooth or scarcely encrusted. Subhymenial hyphae richly branched, thin-walled, 2 –3.5(– 4.5) μm diam., smooth or slightly encrusted. Aculei consisting mostly of projecting hyphae. Projecting hyphae moderately flexuous, (3 –)3.5– 5 μm diam., slightly thick-walled, loosely encrusted, clamped at septa. Capitate cystidial elements found mostly in subhymenium and subiculum, scattered to frequent, terminal or lateral, smooth, thin- to thick-walled, aseptate or with adventitious septa, (8 –)15– 30 × (4.5 –)5–6.5(– 8.5) μm. Basidioles clavate to subcylindrical, sometimes slightly tapering to apex, 7-22 × 4-5 μm. Basidia cylindrical, sometimes slightly constricted, 16-30 × 4-4.3 μm, thin-walled, smooth, with four sterigmata about 2.5 × 0.2 μm. Spores narrowly ellipsoid to oblong, 5 –6(– 6.3) × (2.5 –)3– 3.5 μm, holotype L = 5.5 μm, W = 3.2 μm, Q = 1.7, thin- or slightly thick-walled, colourless, smooth, with minute apiculus, inamyloid, indextrinoid, weakly cyanophilous.

Distribution and ecology.

South-eastern USA and Central America, on dead wood of angiosperms.

Etymology.

From Greek pseudo- - false, refers to its similarity to X. lanatus .

Additional specimens examined.

USA: Alabama, Escambia County, 3 miles east of Flomaton, on bark of Taxodium distichum (L.) Rich. (CFMR FP-103492), on bark of Quercus sp. (CFMR FP-103500), leg. A.S. Rhoades, 1 Nov 1952; Florida, Marion County, Okalawaha River, on dead inflorescence of Sabal palmetto (Walter) Lodd. ex Schult. & Schult. f., leg. H.H. Burdsall, Jr., 3 Aug 1972 (CFMR HHB-6925; dupl. in KAS and MSK); Louisiana, Baton Rouge, on Melia azedarach L., leg. C.J. Humphrey & C.W. Edgerton, 29 Aug 1909 (CFMR FP-5519).

Remarks.

The diagnostic features of this species are the minutely odontioid hymenophore, bundles of sparsely to moderately encrusted hyphae, projecting from aculeal apices, embedded capitate cystidia, cylindrical basidia and narrowly ellipsoid basidiospores. Some hymenial elements in this species are intermediate in morphology between basidioles, capitate cystidia and hyphal ends. Xylodon pseudolanatus can be distinguished from similar species in the key below (see Discussion).