Neotherrya nematoidea Lan Zhuo & C. L. Hou, 2025

Zhuo, Lan, Wang, Hai-Qi, Zhang, Peng, Sui, Xiao-Nan, Guo, Mei-Jun, Wang, Shi-Juan & Hou, Cheng-Lin, 2025, New genera and species of coniferous twig-inhabiting Rhytismatales from China, IMA Fungus 16, pp. e 138790-e 138790 : e138790-

Neotherrya nematoidea Lan Zhuo & C. L. Hou sp. nov.

Figs 24 , 25

Etymology.

Nematoidea (Latin) = nematode-like, refers to the shape of the released ascospores.

Diagnosis.

This new species is distinguished from Neotherrya abieticola by N. nematoidea having filiform ascospores with 1–3 - septa.

Type.

CHINA, Yunnan Province, Lijiang, Laojunshan , 26.6323°N, 99.7252°E, alt. ca. 3880 m, on twigs of Abies georgei ( Pinaceae ), 16 Jul. 2020, C. L. Hou, M. J. Guo, and Q. T. Wang, HOU 1598 B ( BJTC 2020038 , holotype) .

Sexual morph.

Ascomata on twigs, erumpent from bark, scattered, not associated with pale areas. In surface view, ascomata round to irregular, 750–1000 µm, black (# 000000), opening by irregular splits to expose a pale yellow (# ffff 9 d) hymenium. Lips absent. In median vertical section, covering stroma 40–60 μm thick near the center of ascomata, extending to the basal Covering stroma, consisting of carbonized, angular to globose cells. Periphysoids present. On inner surface of thecovering layer close to opening, a layer formed by periphysoids embedded in gelatinous matrix. Excipulum well-developed, formed by marginal paraphyses. Basal Covering stroma absent. Internal matrix of Covering stroma well-developed, consisting of hyaline hyphae and angular to globose cells. Subhymenium 15–25 µm thick, consisting of hyaline, angular cells. Paraphyses aseptate, filiform, not branched, swollen to 2–3 µm diam. at tips, 160–190 × 1–2 µm, covered by a thin gelatinous sheath. Asci ripening sequentially, clavate, apex obtuse, 110–170 × 10–13 µm, thin-walled, J –, 4 - spored. Ascospores 1–3 - septate, usually 3 - septate, with shapes of nematode, tapering at both ends, 65–100 × 2–3 μm, hyaline, without gelatinous sheaths.

Asexual morph.

Conidiomata and zone lines not seen.

Additional specimens examined.

CHINA, Yunnan Province, Lijiang, Laojunshan , 26.6323°N, 99.7252°E, alt. ca. 3880 m, on twigs of Abies georgei ( Pinaceae ), 26 Jul. 2024, C. L. Hou, L. Zhuo, and X. N. Sui, HOU 2305 ( BJTC 2024155 ) .

Distribution.

Known only from Yunnan Province, China.

Notes.

Neotherrya nematoidea is closely related to N. abieticola in the phylogenetic tree, but N. abieticola has fusiform ascospores that are much shorter (30–50 × 2.5–4.5 µm) than the ascospores of N. nematoidea (65–100 × 2–3 μm) and lacks periphysoids.

Figures

Figure 24. Neotherrya nematoidea (HOU 1598 B / BJTC 2020038, holotype) a ascomata on a twig of Abies georgei b, c mature ascomata. Scale bars: 2 mm (a); 1 mm (b); 500 μm (c).

Figure 25. Neotherrya nematoidea on Abies georgei (HOU 1598 B / BJTC 2020038, holotype) a part of an ascoma in vertical section, periphysoids present, embedded in gelatinous matrix b paraphyses, mature asci with ascospores, and immature ascus c liberated ascospores. Scale bars: 100 μm (a); 10 μm (b, c).