Sebipora aquosa

Sebipora aquosa Miettinen 2012, in Miettinen, & Rajchenberg, Mycological Progress, 11, 131-147 (2012).

Etymology: Sebum (Lat.), refers to the tallow look of pore surface of the type species, aquosus (Lat.), watery, refers to fresh fruiting bodies of the species.

Diagnosis Basidiocarp resupinate to pileate, annual, pure white when fresh, upper surface hairless, azonate, in dry specimens shiny cream with greyish, yellowish and brownish hues, pore surface turning greyish, sometimes with yellow or brown hues, 2–10×1–5 cm wide, caps projecting up to 3 cm, 1–9 mm thick, always broadly attached. Consistency rubber-like but easy to tear apart when fresh, often watery, hard when dry. Pores rather regular, rounded angular, rather thin-walled, tubes white to cream in cross section when dry, 4–6/mm, 1–4 mm long. Subiculum white, homogenous, subiculum of the resupinate part 0.1–0.4 mm, cap context 1–6 mm thick. Cap margin sharp, resupinate margin thinning out but well delineated. Mycelial cords absent.

Hyphal system monomitic, CB–, IKI–, KOH–, CRB+. Hyphae rather homogenous throughout the fruiting body, (2.0)2.7–3.9(4.8) μm in diameter in subiculum, (2.2)2.6– 3.7(5.0) μm in trama, clamps always present. Crystals present as sandy encrustation in tube mouths and trama or small thorny crystal clusters attached to tramal hyphae, scanty to abundant; sometimes also large rhomboidal plates and irregular crystal clusters in subiculum and upper trama. Subicular hyphae interwoven, slightly thick-walled to thickwalled, lumen very distinct and usually at least half of the total width, walls 0.3–1.7 μm thick. Contextual hyphae subparallel, horizontal, slightly thick-walled to thick-walled, relatively loose, (2.7)3.2–4.6(5.8) μm in diameter. Upper surface consists of partly agglutinated layer of interwoven hyphae. Tramal hyphae subparallel, slightly thick-walled, tissue dense, partly agglutinated. Subhymenial hyphae thin-to slightly thick-walled. Free-floating, hyaline oil in microscopic slides present, scanty to abundant. Cystidia absent.

Hymenium. Basidia clavate, 11–20.5×4.8–6.5 μm, with 4 sterigmata, 2.2–3 μm long. Cystidioles absent. Basidiospores cylindrical, often slightly curved, thin-walled, smooth, (5.2)5.7–7.6(8.0)×(2.0)2.1–2.7(2.8) μm, Length=6.44 μm, Width=2.39 μm, Q′=(2.2)2.3–3.3(3.6), Q=2.7, n=96/3, with 1–2 oil drops, apiculus inconspicuous.

Index Fungorum Number: IF519513

Figure 1 Cinereomyces clade consensus phylogram of the 4,503 trees retained in the Bayesian analysis of nrDNA ITS region. Numbers represent Bayesian posterior probabilities. Branch lengths reflect expected changes per site as indicated by the scale.

Figure 2. Sebipora aquosa. Spores from a holotype, b Miettinen 8680.1 and c Miettinen 9265.1. Holotype, d context, e trama, f tramal encrustation and g hymenial cells.