Stipamyces massonianae 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-

Stipamyces massonianae Lan Zhuo & C. L. Hou sp. nov.

Figs 30 , 31

Etymology.

Referring to the host, Pinus massoniana Lamb. ( Pinaceae ).

Diagnosis.

This new species is similar to Stipamyces pinicola , but the ascomata of Stipamyces massonianae have longer stalks, and paraphyses are sometimes branched at their tips.

Type.

CHINA, Anhui Province, Anqing , Yuexi County, alt. ca. 1000 m, on twigs of Pinus massoniana , 20 Apr. 2015, C. L. Hou, HOU 1215 ( BJTC 2015001 , holotype) .

Sexual morph.

Ascomata on twigs, aggregated in groups of two to five, not associated with pale areas. In surface view, ascomata round to irregular, 875–1925 µm in diam., 1000–1600 µm high, black (# 000000), erumpent from bark, opening by irregular splits to expose a yellow (# ffd 400) hymenium. Lips absent. In median vertical section, covering stroma 30–50 μm thick near the center of the ascomata, extending to the base, consisting of an outer layer of remains of the host cortex, an inner layer of carbonized, angular cells, and an innermost layer of hyaline angular cells. Periphysoids on the inner surface of thecovering layer close to the opening, another layer formed by paraphysoids embedded in a gelatinous matrix. Basal Covering stroma absent. Internal matrix of Covering stroma well-developed, consisting of hyaline, interwoven hyphae. Subhymenium 65–80 µm thick, consisting of small, hyaline cells. Paraphyses aseptate, filiform, circinate, sometimes branched at tips, 100–145 × ca. 1 µm. Asci ripening sequentially, clavate, slightly truncate at the apex, 40–130 × 4–14 µm, stalked, thin-walled, J –, 8 - spored. Ascospores aseptate, long-fusiform, acute at both ends, 25–40 × 2–4 μm, hyaline, not covered by a gelatinous sheath.

Asexual morph.

Conidiomata and zone lines not seen.

Distribution.

Known only from Anhui Province, China.

Notes.

The phylogenetic analysis shows that S. massonianae is congeneric with S. pinicola , but the latter has shorter stalks on ascomata, a thinnercovering layer, and unbranched tips of paraphyses. The sequence similarity of ITS rDNA between these species is 93 %, indicating that S. massonianae is a distinct species.

Figures

Figure 30. Stipamyces massonianae (HOU 1215 / BJTC 2015001, holotype) a ascomata on a twig of Pinus massoniana b, c mature ascomata. Scale bars: 3 mm (a); 1 mm (b, c).

Figure 31. Stipamyces massonianae on Pinus massoniana (HOU 1215 / BJTC 2015001, 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: 200 μm (a); 25 μm (b); 10 μm (c).