Crepidotus viscidus Phonemany, Thongkl. & Sysouph.

Phonemany, Monthien, Sysouphanthong, Phonguen & Thongklang, Naritsada, 2024, Additions to Crepidotus species (Basidiomycota): Six new species and two new records from Thailand, Phytotaxa 646 (2), pp. 91-115 : 109-110

Crepidotus viscidus Phonemany, Thongkl. & Sysouph. , sp. nov. ( Figures 16–17 )

Faces of fungi number: FoF 150103, MycoBank: MB 850915

Etymology:— viscidus refers to viscid or striky basidiomata.

Holotype:— THAILAND. Roi Et Province, Mayyadee District, Tambol Somsaart, Pa Phu Khao Thong Wild Temple, 16°25’55’’N, 103°51’18’’E, 18 August 2020, Monthien Phonemany ( MFLU23-0432 ).

Diagnosis:—This species is distinguished from other Crepidotus species by having a white semicircular pileus, translucent-striate with gray to dark gray margin, pale orange to orange-white lamellae, glutinous context, smooth basidiospore, and hymenophoral trama present regular form.

Description: Basidiomata pleurotoid, small. Pileus 10–18 × 5–12 mm; semicircular, spathuliform, with incurved to straight margin; white (3A1) to pastel yellow (3A4); smooth, slightly viscid, not hygrophanus, the attachment zone covered by white woolly hyphae; margin zone, gray (1E1) to dark gray (1F1), with translucent-striate. Lamellae 1 mm wide, when young, white, becoming pale orange (5A2) to orange white (5A1), finally light brown with age (5D8). Stipe absent or pseudostipe. Context 1 mm wide, white, glutinous. Odor and taste none. Spore print brownish (6D8) to brown (6E8).

Basidiospores [150/3/3] (5–)5.4–6.3–7.4(–7.8) × (3.9–)4.2–4.8–5.4(–5.9) µm, Q = (1.04–)1.11–1.32–1.51(–1.54), globose to subglobose, ellipsoid in side view, smooth, yellow to light orange-yellow in KOH, brown in water, thin, thick-walled. Basidia (15.5)15.5–19.8–25.3(–25.3) × (5.8–)5.8–6.7–7.7(–7.7) µm, subclavate, 4-spored, sterigmata 3–5 µm long, hyaline, smooth, thin-walled. Cheilocystidia (13.5–)13.5–22.1–32.7(–32.7) × (5.6–)5.6–8.4–11.2(–11.6) µm, subcylindrical, narrowly utriform to utriform, fusiform to broadly fusiform, lecythiform to sublecythiform, with subcapitate at apex, hyaline, smooth, thin-walled. Pleurocystidia absent. Hymenophoral trama regular to subregular, hyphae 2–4 µm wide, hyaline. Pileipellis a cutis, composed of parallel hyphae 4–8 µm wide, branched, hyaline, with cylindrical terminal elements 56–90 × 5–7 µm. Oleiferous hyphae 2–4 µm present in hymenophoral trama. Clamp connections are present in all structures.

Habitat and distribution:—Saprobic on dead wood, scattered or fasciculate by 4–10 basidiomata. So far, this has only been found in northeast and northern Thailand.

Additional specimens examined:— THAILAND, Chiang Mai Province, Mae on District, Pox Kaew Village, 18°52’1”N, 99°19’29” E, 25 June 2019, Monthien phonemany (MFLU23-0431). Roi Et Province, Mayyadee District, Somsaart Subdistrict, 16°25’49.7”N, 103°51’26.2”E, 18 August 2020, Monthien Phonemany (MFLU23-0433), (MFLU23-0434).

Figures

FIGURE 16. Basidiomata of Crepidotus viscidus in the field. a–c= MFLU23-0432, d = MFLU23-0434. Scale bar a–d = 10 mm.

FIGURE 17. Micromorphology of Crepidotus viscidus. a Basidiospores, b Basidia, c Cheilocystidia, d Pileipellis, scale bar a = 5 µm, b c = 10 µm, d = 50 µm.