Parahypoxylon ruwenzoriense M. Cedeno-Sanchez , E. Charria-Giron & M. Stadler, 2023

Cedeno-Sanchez, Marjorie, Charria-Giron, Esteban, Lambert, Christopher, Luangsa-ard, J. Jennifer, Decock, Cony, Franke, Raimo, Broenstrup, Mark & Stadler, Marc, 2023, Segregation of the genus Parahypoxylon (Hypoxylaceae, Xylariales) from Hypoxylon by a polyphasic taxonomic approach, MycoKeys 95, pp. 131-162 : 131

Parahypoxylon ruwenzoriense M. Cedeno-Sanchez, E. Charria-Giron & M. Stadler sp. nov.

Figs 5 , 6

Holotype.

Democratic Republic Of The Congo. North Kivu: Mt. Ruwenzori, about 00°33.961'N, 29°81.795'E, between 2,138 and 2,400 m alt., 3-5 Feb 2008, tropical mountain forest, C. Decock (MUCL 51392, ex-holotype culture MUCL 51392).

Etymology.

Named after the Ruwenzori Mountains, where the species was collected.

Teleomorph.

Stromata superficial, incomplete, effused-pulvinate, 60 mm long × 40 mm broad × 3-5 mm thick; surface Fawn (87), with inconspicuous perithecial mounds, with a black, shiny hard crust 100-150 µm thick above perithecia, without visible granules, with KOH-extractable pigments Hazel (88); the pruina hyphae turn violet in KOH; the tissue below the perithecia 2-4 mm thick, vertically fibrose, dark grey. Perithecia tubular, 0.90-1.50 mm high × 0.2-0.3 mm diam (n=18). Ostioles umbilicate, surrounded by a white substance. Asci cylindrical, 8-spored, the spore-bearing parts 82-105 µm long × 5.5-6.0 µm broad, the stipes 38-130 µm long, with amyloid, discoid apical ring 0.7-2.0 µm high × 2.5-3.5 µm (n=21) broad. Ascospores smooth, unicellular, brown to dark brown, narrowly ellipsoid, nearly equilateral with narrowly rounded ends, 10.5-13.8 × 4.0-5.6 µm (n=40), with a faint, straight germ slit; perispore indehiscent in 10% KOH.

Cultures and anamorph.

Colonies on MEA, OA, and YM covering a 9 cm Petri plate in 2 weeks, with mycelium white at first, flat to raised in some zones, to becoming greenish in the center. Reverse at first yellowish, to become orange with a black spot at the center. Conidiophores not produced.

Secondary metabolites.

Stromata contain BNT and cohaerin type azaphilones according to the MS/MS analysis.

Notes.

P. ruwenzoriense is phylogenetically close to P. papillatum but differs by its KOH-extractable pigments Hazel (88) and by smaller ascospores.

Figures

Figure 5. Parahypoxylon ruwenzoriense sp. nov. (MUCL 51392). A stroma B ostioles with white ring C KOH extractable stromatal pigments D perithecia (cross section) E ascospores F amyloid apical apparatus (blueing in Melzer's reagent) indicated by arrowheads G asci. Scale bars: 1 cm (A); 2 mm (D); 10 μm (E, F); 50 μm (G).

Figure 6. Parahypoxylon ruwenzoriense sp. nov. (MUCL 51392) Colonies after 2 weeks (A, B) on 2 % MEA (C, D) on OA (E, F) on YM.