Kirschsteiniothelia jiulianshanensis Y. F. Hu & Jian Ma, 2025

Kirschsteiniothelia jiulianshanensis Y. F. Hu & Jian Ma sp. nov.

Fig. 5 View Figure 5

Type.

China • Jiangxi Province, Ganzhou City, Longnan County, Jiulianshan National Nature Reserve , on dead branches of an unidentified broadleaf tree, 29 June 2022, Y. F. Hu ( HJAUP M 1313 , holotype), ex-type living culture, HJAUP C 1313 = HJAUP C 1314 .

Etymology.

The name refers to Jiulianshan National Nature Reserve, the locality where the fungus was collected.

Description.

Saprobic on decaying wood in terrestrial habitats. Asexual morph: Hyphomycetes. Colonies on natural substratum effuse, dark brown, hairy. Mycelium immersed and superficial, composed of branched, dark brown to black, septate, smooth-walled hyphae. Conidiophores macronematous, mononematous, unbranched, erect, straight or flexuous, cylindrical, smooth, dark brown to black, 7–17 - septate, 128.6–291.4 (– 430) × 7.1–10 μm (x ̄ = 217.4 × 8.46 μm, SD = 85 × 0.7, n = 15). Conidiogenous cells monotretic, integrated, terminal, cylindrical, brown, determinate, or sometimes with several cylindrical, enteroblastic percurrent extensions. Conidia acrogenous, solitary, obclavate, straight or slightly curved, pale brown to brown, 4–7 - euseptate, 31.4–57.1 × 10–11.4 μm (x ̄ = 41.6 × 11.04 μm, SD = 9 × 0.5, n = 20), tapering to 4.6–6 μm at the apex, 2.3–3.4 μm wide at the truncate base, and rounded at the apex. Sexual morph: Undetermined.

Culture characteristics.

Colonies growing on PDA medium reaching 85–90 mm diam. after 4 weeks at 25 ° C in darkness, circular, surface velvety, grey-white in center and brown at margin with dense mycelium, reverse dark brown to black.

Note.

The phylogenetic tree showed that K. jiulianshanensis ( HJAUP C 1313 and HJAUP C 1314 ) clusters with K. laojunensis ( KUN-L 88727 ) and K. thujina (JF 13210). Based on nucleotide comparisons, K. jiulianshanensis ( HJAUP C 1313 ) and K. laojunensis ( KUN-L 88727 ) showed 63 bp differences (3 %, including eight gaps) in ITS and SSU regions; K. jiulianshanensis ( HJAUP C 1313 ) and K. thujina (JF 13210) showed 75 bp differences (7 %, including twelve gaps) in ITS, LSU, and SSU regions. Moreover, K. jiulianshanensis was found only in its asexual morph, while K. laojunensis Q. F. Meng & S. B. Fu ( Meng et al. 2024) and K. thujina (Peck) D. Hawksw. ( Hawksworth 1985) are known only as the sexual morph. In addition, K. jiulianshanensis ( HJAUP C 1313 ) can be distinguished from the morphologically most similar species, K. crustacea S. Wang, Q. Zhao & K. D. Hyde ( Jayawardena et al. 2022), in having longer conidiophores (128.6–291.4 μm vs. 60–170 μm) and smaller conidia (31.4–57.1 × 10–11.4 μm vs. 45–75 × 10–18 μm), and further from K. crustacea by 90 nucleotides (79 / 491 in ITS and 11 / 545 in SSU).