Acervus stellatus Jia Y. Lin, Zhu L. Yang & Kun L. Yang, 2025

Lin, Jia Y., Liu, Zhen-Chao, Li, Guang-Mei, Yang, Zhu L. & Yang, Kun L., 2025, Three new species of Acervus (Ascomycota, Pezizales) from South China, Phytotaxa 700 (1), pp. 73-86 : 81-82

Acervus stellatus Jia Y. Lin, Zhu L. Yang & Kun L. Yang , sp. nov.

Registration identifier: FN572417

Etymology:— Referring to the whitish to palely yellowish colour and the shape of this fungus, which resemble meteors.

Diagnosis:— Differs from Acervus epispartius f. albus Korf & W.Y. Zhuang (1989: 297) by the larger apothecium, broader ascospores, longer and wider asci, wider paraphyses, the medullary excipulum of a textura angularis to textura globulosa and the ectal excipulum of a textura angularis, textura globulosa to textura epidermoidea, and from other species of Acervus by the whitish to palely yellowish ascomata.

Type:— CHINA. Guangdong Province: Guangzhou City, Tianhe District, South China Agricultural University , a lawn in front of the College of Forestry and Landscape Architecture , on soil, 23°09'34"N, 113°21'40"E, elevation 30 m, August 30, 2023, Jia Y. Lin, L 23338 ( HKAS145957 , holotype! (deposited in the Herbarium of Cryptogams in Kunming Institute of Botany of Chinese Academy of Sciences ; nrLSU: PV168193; rpb1: PV172437; rpb2: PV172439; tef-1α: PV172444 ); HTBM1319 , isotype!) .

Description:— Ascomata small, sessile to shortly stipitate. Apothecium 11–16 mm broad, 3.5–5.5 mm high excluding the stipe, irregularly concave, discoid to nearly plane, usually with an involute margin when mature, arising from a whitish mycelial pad. Hymenium surface smooth, star white (#FBFBEB), garlic yellow (#F1F0D4) to thatch yellow (#F1ECC5) when fresh, becoming bone brown (#E3D3C4), turtledove brown (#D0BCA4) to mongoose brown (#B5A284) after dried. External surface relatively rough, concolorous with hymenium surface . Stipe short or absent, up to 1 mm long, concolorous with hymenium surface . Context thin, fragile, concolorous with hymenium surface . Odour indistinct. Taste unknown.

Ascospores ellipsoid to oblong, uniseriate, nearly colourless, thin- to slightly thick-walled, non-septate, smooth, {40/2/1} 5.5–6.5 [6.05 ± 0.35, 6.00] × 3.5–4.5 [4.00 ± 0.19, 4.00] µm, Q = 1.38–1.71 [1.51 ± 0.09, 1.50] including spore wall, uniguttulate. Asci narrowly cylindrical, operculate, eight-spored, nearly colourless, 80–100 µm in length, with a sporiferous part 42–50 × 5.5–7 µm when mature, with a crozier at the base. Paraphyses abundant, filiform, nearly colourless, 3–4.5 µm wide at the middle, septate, usually unbranched, rarely branched. Subhymenium up to 23 µm thick, nearly colourless. Medullary excipulum up to 150 µm thick, composed of a gelatinized textura angularis to textura globulosa of nearly colourless, 9–31 × 8.5–23 µm, thick-walled cells and some gelatinized, 5–13 µm wide, nearly colourless, thick-walled hyphae. Ectal excipulum up to 105 µm thick, composed of a textura angularis, textura globulosa to textura epidermoidea of nearly colourless, 9.5–40 × 7.5–26 µm, thin-walled cells, with some hyphae up to 7 µm wide and some inflated cells up to 47 µm long and 14 µm wide arising from the external surface.

Habitat and distribution:— Gregarious, on soil of urban green belts. Currently known from South China.