Crepidotus thailandicus 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 : 106-107

Crepidotus thailandicus Phonemany, Thongkl. & Sysouph. , sp. nov. ( Figures 12–13 )

Faces of fungi number: FoF 150101, MycoBank: MB 850914

Etymology:— thailandicus refers to the country “ Thailand ” where the holotype was found.

Holotype:— Holotype. THAILAND, Chiang Mai Province, Mae on District, Pox Kaew Village , 18°52’1”N, 99°19’29”E, 24 June 2019, Monthien Phonemany ( MFLU23-0425 ) .

Diagnosis:—This species is characterized by small to medium basidiomata, tomentose pileus covering with white hair in primordial to young stages and disappeared when mature, with long transtucent-striate, globose to subglobose punctate basidiospores, absence of cheilocystidia and pleurocystidia, a cutis pileipellis and presence of clamp-connections.

Description: Basidiomata pleurotoid, small to medium. Pileus 25–50 × 15–60 mm; rounded flabelliform to reniform, convex in the attachment zone, with an incurved margin when young and going straight to reflexed when mature; white when young, turning yellowish white (4A1) to yellowish gray (4B2), brown (6D6) to light brown (6D7); surface tomentose with white hair in the primordial to young stages, disappearing when mature, the attachment zone covered with white woolly hyphae; margin white, with long translucent-striate reward to the attachment zone. Lamellar 1–2mm wide, adnate, white when young, becoming whitish to pale yellow (4A2) to brown (5D6) when fully mature, crowded, with 4–5 tiers of lamellulae. Stipe 1–2 × 1–1.5 mm, pseudostipe, eccentric to lateral, whitish, translucent, cylindrical. Context 1 mm wide, translucent. Odor mild. Taste none. Spore print brown (5D6).

Basidiospores [150/3/3] (4.9–)5.2–5.9–6.7(–6.9) × (4.7–)4.8–5.3–5.8(–6.2) µm, Q = (1.0–)1.05–1.11–1.22(– 1.29), globose to subglobose, punctate to verrucose, buff yellow to light orange-yellow in KOH, brownish in water. Basidia (15.3–)15.3–20.7–24.9(–24.9) × (6–)6.0–7.5–8.9(–8.9) µm, clavate to subcylindric, hyaline, smooth, thin-walled 4-spored, sterigma long 2–2.5 µm long. Cheilocystidia absent. Pleurocystidia absent. Hymenophoral trama subirregular to subinverse, hyphae 4–8 µm wide, with subcylindrical to sunclavate terminal elements 48.18–104.58 × 12.45–28.72 µm, hyaline. Pileipellis a cutis, composed of parallel hyphae 4–8 µm wide, branched, hyaline, with cylindrical terminal elements 54.6–91.34 × 9.15–14.08 µm. Oleiferous hyphae 2–4 µm present in the hymenophoral trama and pileipellis. Clamp connections are present in all structures.

Habitat and distribution:—Saprobic on dead branches, scattered, or gregarious with at least 3–8 basidiomata. So far, this has only been found in northern Thailand.

Additional specimens examined:— THAILAND, Chiang Rai Province, Mae Fah Luang District, Mae Sa Long Nok Subdistrict, 20°10’10.9”N, 99°37’21.5”E, 10 June 2019, Monthien Phonemany (MFLU23-0424), Chiang Mai Province, Mae on District, Pox Kaew Village, 18°52’1”N, 99°19’29”E 24 June 2019, Monthien Phonemany (MFLU23- 0426).

Figures

FIGURE 12. Basidiomata of Crepidotus thailandicus in the field. a= MFLU23-0424 c–d = MFLU23-0425, d–e = MFLU23-0426. Scale bar a–e = 10 mm.

FIGURE 13. Micromorphology of Crepidotus thailandicus, a Basidiospores, b Basidia, c Pileipellis. Scale bar a = 5 µm, b = 10 µm, c = 50 µm, d = 100 µm.