Cryptococcomyces crystallinus 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-

Cryptococcomyces crystallinus Lan Zhuo & C. L. Hou sp. nov.

Figs 6 , 7

Etymology.

Crystallinus (Latin) = crystal, referring to the internal matrix of Covering stroma filled with numerous crystals.

Diagnosis.

This new species is similar to Cryptococcomyces niger , but differs by an internal matrix of the Covering stroma almost fully filled with crystals.

Type.

CHINA, Yunnan Province, Lijiang, Laojunshan , 26.6326°N, 99.7199°E, alt. ca. 3950 m, on twigs of Juniperus squamata ( Cupressaceae ), 17 Aug. 2023, C. L. Hou, L. Zhuo, and S. Y. Zhao, HOU 2082 ( BJTC 2023212 , holotype) .

Sexual morph.

Ascomata on twigs, erumpent from bark, scattered, not associated with pale areas. In surface view, ascomata round or slightly irregular, 1000–2000 × 750–1000 µm, black (# 000000), opening by radial splits to expose a yellow (# ffd 400) to pale orange (# ffa 500) hymenium. Lips absent. In median vertical section, covering stroma 80–100 μm thick near the center of ascomata, consisting of an outer layer of carbonized, angular to globose cells and an inner layer of hyaline, thin-walled, angular to globose cells. Basal Covering stroma absent. Internal matrix of Covering stroma 240–260 µm thick, consisting of hyaline, thin-walled, angular cells, with abundant irregular crystals in the matrix. Subhymenium 15–20 µm thick, consisting of hyaline textura porrecta. Paraphyses aseptate, filiform, not branched, slightly curved at tips, 110–130 × 1–2 µm, covered by a thin gelatinous sheath. Asci ripening sequentially, clavate, apex acute, 85–105 × 7–8 µm, stalked, thin-walled, J –, 8 - spored. Ascospores aseptate, filiform, tapering towards apex, 40–60 × 1–2 μm, hyaline, with a gelatinous cap.

Asexual morph.

Conidiomata and zone lines not seen.

Additional specimens examined.

CHINA, Yunnan Province, Lijiang, Laojunshan , 26.6319°N, 99.7252°E, alt. ca. 3860 m, on twigs of Juniperus squamata ( Cupressaceae ), 16 Aug. 2023, C. L. Hou, L. Zhuo, and S. Y. Zhao, HOU 2028 ( BJTC 2023158 ) ; 26.6318°N, 99.7250°E, alt. ca. 3930 m, on twigs of J. squamata , 16 Aug. 2023, C. L. Hou, L. Zhuo, and S. Y. Zhao, HOU 2030 ( BJTC 2023160 ) ; 26.6319°N, 99.7244°E, alt. ca. 3890 m, on twigs of J. squamata , 17 Aug. 2023, C. L. Hou, L. Zhuo, and S. Y. Zhao, HOU 2062 ( BJTC 2023192 ) .

Distribution.

Known only from Yunnan Province, China.

Notes.

The multi-locus gene analysis shows that the sequences of Cry. crystallinus form a well-supported clade sister to the sequences of Cryptococcomyces sp. 2 . However, the specimens of Cryptococcomyces sp. 2 do not have any mature ascoma; therefore, these two species cannot be compared morphologically. The ITS rDNA sequence similarity between these two species is 92 %, so we treat Cry. crystallinus as a separate species. Morphologically, Cry. crystallinus is similar to Cry. niger , but Cry. niger differs by an internal matrix of the Covering stroma lacking crystals.

Figures

Figure 6. Cryptococcomyces crystallinus (HOU 2082 / BJTC 2023212, holotype) a ascomata on a twig of Juniperus squamata b, c mature ascomata. Scale bars: 2 mm (a); 500 μm (b, c).

Figure 7. Cryptococcomyces crystallinus on Juniperus squamata (HOU 2082 / BJTC 2023212, holotype) a part of an ascoma in vertical section, the internal matrix of Covering stroma filled with numerous crystals b paraphyses, mature asci with ascospores, and immature ascus. c Liberated ascospores with gelatinous cap. Scale bars: 100 μm (a); 10 μm (b, c).