Crepidotus ungulatus 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 : 108

Crepidotus ungulatus Phonemany, Thongkl. & Sysouph. , sp. nov. ( Figures 14–15 )

Faces of fungi number: FoF 150102, MycoBank: MB 850910

Etymology:— ungulatus refers to the ungulate shape of basidiomata.

Holotype:— THAILAND. Chiang Mai Province, Mae Taeng District, Tha Pha Village, Highway 1095 at 22 km marker of Mae Ma Lai-Pai Road , 19°07’36’’N, 98°45’48’’E, 15 July 2020, Monthien Phonemany ( MFLU23-0429 ).

Diagnosis:—This species is recognized by a small ungulate to spathulate basidiomata, white to light brown pileus, the absence of pseudostipe, broadly ellipsoid to subcylindrical basidiospores, lecythiform to sublecythiform cheilocystidia with subcapitate apex, absent pleurocystidia, a cutis pileipellis, the absence of oleiferous hyphae and clamp connections present.

Description: Basidiomata pleurotoid, small. Pileus 10–15 × 10–20 mm; ungulate to spathulate, with inflexed margin to involute margin; white when young, brownish orange (5C4–5, 5D5) near point of attachment, becoming light brown when mature (5D4–5); smooth, hygrophanous, covered with white woolly hyphae in the attachment zone; margin sulcate-striate, concolorous to the pileus surface. Lamellae up to 1 mm wide, decurrent, white when young, becoming pale yellow to yellowish (4A3–4A2), finally light brown (5D4–5), moderately crowded, with 4–5 tiers of lamellulae, with smooth edge. Stipe absent or pseudostipe, very short. Context is very thin, soft, and white. Odor none, taste none. Spore prints brown (6D 6, 6E 6).

Basidiospores [150/3/2] (5.5–)5.5–6–10.7(–11.2) × (4–)4–4.5–5.2(–5.4) µm, Q = (1.19–)1.25–1.51–2.56(– 2.64), broadly ellipsoid to elongate, buff yellow to light orange-yellow in KOH and water, smooth, thick-walled. Basidia (12.1–)12.1–16.0–20.1(–20.6) × (4.8–)4.9–6.0–7.8(–7.8) µm, subclavate to clavate, 4-spored, sterigma 5–7 µm long, hyaline, smooth, thin-walled. Cheilocystidia (15.6–)15.6–28.3–75.3(–75.8) × (5–)5.2–9.5–23.7(–23.7) µm, narrowly lecythiform, lecythiform to sublecythiform with subcapitate at apex, hyaline, smooth, thin-walled. Pleurocystidia absent. Hymenophoral trama irregular, cylindrical hyphae 3–9 µm wide. Pileipellis a cutis composed of parallel hyphae 3–8 µm wide, hyaline, with cylindrical terminal elements 45.0–66.8 × 8.4–11.2 µm. Oleiferous hyphae absent. Clamp connections are present in all structures.

Habitat and distribution:—Saprobic on the dead branch, scattered with at least 10 basidiomata. So far, this has only been found in northern Thailand.

Additional specimens examined:— THAILAND. Chiang Mai Province, Mae Taeng District, Pang Hang Village, 19°07’44.8”N, 98°45’47.8”E, 15 July 2020, Monthien Phonemany (MFLU23-0430).

Figures

FIGURE 14. Basidiomata of Crepidotus ungulatus in the field. a–b MFLU23-0429, c MFLU23-0430. Scale bar a–e = 10 mm.

FIGURE 15. Micromorphology of Crepidotus ungulatus, a Basidiospores, b Basidia, c Cheilocystidia, and d Pileipellis. Scale bar a–b = 10 µm, c = 20 µm, d = 50 µm.