Polycephalomyces tengchongensis Y. Wang tris & T. C. Wen sp. nov.

Fig. 3

Etymology.

Named after the location where the type specimen was found, Tengchong County, Yunnan Province.

Description.

Parasitic on Perennicordyceps cf. elaphomyceticola . Sexual morph: Undetermined. Asexual morph: Synnemata 18.7 mm long, 1–2 mm wide, cylindrical, white, growing in small group on stromata of Perennicordyceps cf. elaphomyceticola . Fertile parts yellowish, with conidial mass forming on middle part of synnemata. Phialides dimorphic. α-phialides 9–20 × 1–2 μm (x ̄ = 12.3 × 1.2 μm, n = 45), phialidic, subulate, hyaline, smooth-walled, arranged in a parallel palisade-like layer around the fertile part. α-conidia 1–3 μm (x ̄ = 2 μm, n = 45), globose, hyaline.

Culture characters.

Colonies on PDA attaining a diam. of 28–31 mm in 14 days at 25 ° C, white, leathery, radially striate, reverse dark brown and turns pale outward. β-phialides 18–44 × 1–3 μm (x ̄ = 26.7 × 1.2 μm, n = 30), phialidic, lanceolate, smooth-walled. β-conidia 3–7 × 1.5–3 μm (x ̄ = 3.9 × 2.2 μm, n = 45), ellipsoidal to broadly fusiform, hyaline, aseptate, smooth-walled.

Material examined.

China • Yunnan Province, Tengchong County, Houqiao Town; 5 Nov. 2022; Collected by Yi Wang; Parasitic on the stromata of Perennicordyceps cf. elaphomyceticola; GYY 547 (HKAS 131923, ex-holotype living culture: KUNCC 23-16073) .

Notes.

The newly described species Polycephalomyces tengchongensis is closely related to Po. formosus with strong support (MLBS = 100 %, MIPP = 1.00, Fig. 1). However, Polycephalomyces tengchongensis is distinct from Po. formosus in several aspects. It parasitizes Perennicordyceps cf. elaphomyceticola and produces synnemata without well-defined stipe and a fertile head but features dimorphic phialides and conidia. In contrast, Po. formosus has stipitate synnemata with a fertile head at the tip and produces only one type of phialides and conidia (Xiao et al. 2023).

A comparison of nucleotide sequences between Po. tengchongensis and the ex-type of strain of Po. formosus (NBRC 109993) revealed 1 % differences (6 / 584 bp) including three gaps in the ITS region, 0.3 % (3 / 774 bp) differences including one gap in the LSU region, 2.3 % differences (16 / 684 bp) including three gaps in the rpb 1 region and 1.6 % differences (15 / 891 bp) in the rpb 2 region. Collectively, the differences both in phenotypic profiles and nucleotides sequences support the establishment of Polycephalomyces tengchongensis as a new species.