Dextrinoporus aquaticus

Dextrinoporus aquaticus H.S. Yuan 2018, in Yuan & Qin, Mycological Progress, 17, 773-780 (2018).

Etymology: aquaticus (Lat.): refers to the watery basidiocarps when fresh.

Diagnosis: Basidiocarps annual, pileate, applanate, broadly attached, watery and fleshy, without special odor or taste when fresh, up to 15 cm broad, 7 cm wide and 4 cm thick at the base; shrinking dramatically when dry, up to one third of original size, hard corky to cartilagineous.

Pileal surface cream, buff to pinkish buff when fresh, orange brown to fawn color when dry, hirsute to tomentose, azonate; margin obtuse; pore surface buff to pinkish buff when fresh, fuscous to vinaceous brown upon drying, pores angular to irregular, 1–2 per mm, dissepiments thin, entire; sterile margin up to 2 mm wide. Context duplex, upper layer white to cream, fleshy, up to 8 mm thick when fresh, hyphae vertical arranged, azonate; lower layer cream to buff, 1.5-cm thick when fresh, hyphae horizontal arranged, distinctly zonate. Tubes non-stratified, white to cream, leathery, up to 2-cm thick when fresh; clay buff, hard corky to sub-cartilagineous when dry.

Hyphal structure—Hyphal system monomitic; generative hyphae bearing clamp connections, dextrinoid in IKI, CB+; tissues unchanged in KOH. Context—Hyphae of upper layer agglutinated in groups and difficult to separate; hyphae of lower layer clustered in groups but discernible. Hyphae hyaline, slightly thick-walled, occasionally branched, 3–8-μm diameter, regularly arranged. Tubes—Generative hyphae hyaline, slightly thick- to thick-walled, occasionally branched, loosely interwoven, 3–6-μm diameter. Dendrohyphidia present, easily find in Melzer’s reagent, arising from sub-hymenium, thin-walled, apical tortuous or moderately branched, 20–28 × 4–6 μm. Basidia clavate, bearing four sterigmata and a clamp connection at the base, 18–23 × 7–8 μm. Basidioles similar to basidia in shape, but slightly smaller.

Spores—Basidiospores broadly ellipsoid, hyaline, thin-walled, smooth, IKI–, CB–, (7.2–)7.3–8.4(−8.8) × 5–6(−6.2) μm, L = 7.81 μm, W= 5.49 μm, Q = 1.41–1.44 (n = 60/2).

Index Fungorum Number: IF822279