Tremellodendropsidales » Agaricomycetes genera¬†incertae sedis » Purpureocorticium

Purpureocorticium microsporum

Purpureocorticium microsporum S.H. Wu 2017, in Wu et al., Mycological Progress, 17, 357-364 (2018).

Etymology: From micro + spore, referring to the small basidiospores

Diagnosis: Fruit body effused, adnate, membranaceous, 100250 μm thick in section. Hymenial surface white when fresh, turning purple in KOH, becoming purplish pink or pinkish purple after storage of several years, smooth, cracked when dry; margin thinning, byssoid, glossy. Hyphal system monomitic; hyphae nodose-septate. Subiculum fairly uniform, composed of medullary layer, with compact texture; hyphae colorless, interwoven, and with irregular orientation, tortuous, indistinct, ± agglutinated, occasionally irregularly swollen, variable in diam., 16 μm, thin-walled. Fairly big crystals crowded at basal subiculum. Hymenial layer not clearly differentiated from subiculum, may be thickening. Cystidia lacking. Basidia subclavate with a median constriction, or utriform, 1323 × 3.34.3 μm, 4-sterigmate. Basidiospores small, ovate-ellipsoid, smooth, thin-walled, often with one oily drop, (2.7–)2.83.2(−3.3) × 22.2(−2.3) μm [Wu 0806-27: L= 2.97 ± 0.10 μm, W= 2.08 ± 0.07 μm, Q = 1.43 (n = 30)], inamyloid, nondextrinoid, acyanophilous.

Index Fungorum Number: IF809434

Notes: Cultural description (Wu 0806-27). 1 wk. growth: Colony radius 1925 mm. Matt white. Advancing zone even. Aerial mycelium absent. 2 wk. growth: Colony radius 3947 mm. Matt white. Advancing zone even. Aerial mycelium absent or slightly pellicular, slightly zonate. 3 wk. growth: Plates partly covered. 6 wk. growth: Matt white. Aerial mycelium almost absent, slightly granular near plate margin. Odor slightly fragrant. Agar unchanged. Fruiting with basidia and basidiospores. Hyphal system monomitic. Advancing hyphae colorless, (1–)1.54(−5) μm diam., thin-walled, sparsely branched, nodose-septate. Aerial generative hyphae colorless, (1–)1.54(−5) μm diam., thin-to slightly thick-walled, nodose-septate, moderately or sparsely branched. Submerged hyphae colorless, 1.55 μm diam., generally thin-walled, occasionally slightly thick-walled, nodose-septate, moderately or sparsely branched. Cuboid crystals present in the agar. Oxidase reactions. TAA: +++, 611; +++, 1830. GAA:+++, tr.; ++++, tr. TYA: − (slightly yellowish brown), 1824;− (slightly yellowish brown), 4754. Species code. 2a, 3c, 7, 36, 40, 43, 48, 50, 54.

Figure 1. Purpureocorticium microsporum (holotype). a Basidiocarp section. b Subicular hyphae. c Basidioles. d Basidia. e Basidiospores.