Crepidotus roseocarpus 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 : 103

Crepidotus roseocarpus Phonemany, Thongkl. & Sysouph. , sp. nov. ( Figures 8–9 )

Faces of fungi number: FoF 15099, MycoBank number: MB 850912

Etymology:— roseo refers to pink, and carpus refers to body; roseocarpus refers to pink basidiomata of the holotype.

Holotype:— THAILAND. Chiang Rai Province, Mae Sai District, Huai Khrai Village , 20°16’05.2”N, 99°51’21.0”E, 3 October 2020, Yuwei Hu ( MFLU23-0435 ).

Diagnosis:—This species is characterized by having large pastel pink to pinkish all parts of basidiomata, ungulate to flabelliform pileus, absence of stipe, globose to subglobose punctate basidiospores, absence of cheilo- and pleurocystidia convergent hymenophoral trama with cylindrical terminal elements, a cutis pileipellis, and presence of clamp-connections.

Description: Basidiomata pleurotoid, small to medium. Pileus 15–30 × 10–45 mm; ungulate to spathuliform, flabelliform, with an inflexed margin when young and turning straight when mature; rose or pastel pink (11A5), pale red (10B6), pinkish (10A3–2); smooth or slightly fibrillose; with a split or sulcate-striate margin when mature, concolorous with surface or paler with pinkish white (11A2) when mature. Lamellae 2–4 mm wide, adnexed to sinuate, rose or pastel pink (11A5), subdistant to moderately crowded, with 4–5 tiers of lamellulae, smooth edge. Stipe 2 mm, present when primordial stages, cylindrical, pale red (10A4), smooth, not present in mature stages. Context 1–3 mm thick, thicker near the point of attachment then thinner toward the margin, pinkish to white (10A2–1). Odor and taste indistinct, mild. Spores print brown (6D 6, 6E 6).

Basidiospores [150/3/3] (5.6–)5.7–6.3–6.9(–7.5) × (5–)5.0–5.4–6.2(–6.6) µm, Q = (1.05–)1.08–1.16– 1.31(–1.34), globose to subglobose, rough or punctate, thick-walled, light brown. Basidia (13.4–)13.9–18.4–21.6(–21.6) × (5–)5.1–6.1– 7.4(–7.5) µm, clavate, hyaline, smooth, thin-walled, 4-spored, with short sterigma. Cheilocystidia absent. Pleurocystidia absent. Hymenophoral trama convergent, with terminal elements (45.5–)45.5–75–93.5(–93.5) × (12.1–)12.1–17.6– 20.4(–20.4) µm, hyaline, smooth, thin-walled. Pileipellis a cutis composed of cylindrical hyphae with sometimes swollen or interwoven, terminal cells cylindrical, (52.6–)52.6–76.2–111.7(–111.7) × (7.6–)7.6–10.8–13.5(–13.5) µm, hyaline, interwoven hyphae, smooth hyaline, 10–25 µm wide. Clamp connections present in pileipellis, pileus trama, and hymenophoral trama.

Habitat and distribution:—Saprobic on the bark of a living tree, scattered or fasciculate by 3–15 basidiomata. So far, this has only been found in tropical forests in northern Thailand.

Additional specimens examined:— THAILAND. Chiang Rai Province, Mae Sai District, Sala Choeng Doi, 20°16’35.4”N, 99°50’34.5”E, 3 October 2020, Monthien phonemany (MFLU23-0436), (MFLU23-0437).

Figures

FIGURE 8. Basidiomata of Crepidotus roseocarpus in the field. a–b MFLU23-0435, c–f MFLU23-0437. Scale bar a–f = 10mm.

FIGURE 9. Micromorphology of Crepidotus roseocarpus, a Basidiospores, b Basidia, c Pileipellis, d swollen hyphae in pileipellis. Scale bar a–d = 10 µm.