Szaferohypha enigmatica Piatek, Stryjak-Bogacka & Czachura 2024, sp. nov.

Szaferohypha enigmatica Piątek, Stryjak-Bogacka & Czachura sp. nov. Figs 2, 3, 4 Etymology. Refers to the uncertain taxonomic position of this fungus after the first molecular analyses. DNA barcodes. ITS (PQ 479987), LSU (PQ 479989), SSU (PQ 479988), rpb 2 (PQ 475069). Typus. Poland • Małopolska Province, Tarnów County: Tarnów–Piaskówka, municipal greenery, isolated from sooty mould community on Symphoricarpos albus leaves, 1 Oct. 2018, leg. M. Piątek, W. Bartoszek & P. Czachura (holotype KRAM F -59996; culture ex-type: G 191 = CBS 152426). Description. Mycelium composed of branched, septate, hyaline, subhyaline, pale brown, or brown, smooth or verrucose, usually thick-walled hyphae, 2–4 µm, sometimes with oil guttules; wall ca. 0.5 µm thick. Conidiophores micronematous, reduced to conidiogenous cells, rarely macronematous. Conidiogeneous cells terminal, rarely lateral, monoblastic, hyaline, subhyaline, pale brown, or brown, 3.5–13.5 × 2.5–4.5 µm. Conidia globose, subglobose, rarely broadly ellipsoid, hyaline, subhyaline, or brown, aseptate, rarely with 1–2 septa or muriformly septate, smooth or finely verrucose, thick-walled, 6.5–15 × 6–13.5 µm, sometimes germinating into hypha or produced intercalary, wall ca. 0.5–1.5 µm thick. Culture characteristics. Colonies on MEA erumpent, spreading, umbonate, grayish, reaching 1 mm diam. after 4 weeks at 6 ° C, 4 mm diam. after 4 weeks at 15 ° C, and 8 mm diam. after 4 weeks at 25 ° C, with a velvety surface caused by abundant aerial mycelium, margin entire. Reverse black. Colonies on PDA erumpent, spreading, umbonate, grayish-brown, reaching 3 mm diam. after 4 weeks at 6 ° C, 4 mm diam. after 4 weeks at 15 ° C, and 7 mm diam. after 4 weeks at 25 ° C, with a velvety surface caused by abundant aerial mycelium, margin finely undulate. Reverse black. Notes. Colonies photographed after 15 weeks of growth, depicted in Fig. 2 g, h, are radially folded on MEA or folded on PDA, possess abundant aerial mycelium, grayish with white patches on MEA and brown with grayish patches on PDA, and are distinctly undulate at the margin. Based on a megablast search of NCBI’s GenBank nucleotide database, the closest hits of the named species using the ITS sequence are Pseudoarthrographis phlogis (strain CPC 32759, GenBank MH 327796; identities = 370 / 414 (89 %), 11 gaps (2 %)), Oncopodiella trigonella (strain FMR 10788, GenBank KY 853455; identities = 356 / 408 (87 %), 11 gaps (2 %)), and Xylographa parallela (voucher Z. Palice 22099 (PRM), GenBank MK 778618; identities = 344 / 396 (87 %), seven gaps (1 %)). The closest hits of the named species using the LSU sequence are Beaucarneamyces stellenboschensis (strain CPC 45687, GenBank PP 791445; identities = 826 / 873 (95 %), four gaps (0 %)), Pseudoarthrographis phlogis (strain CPC 32759, GenBank NG _ 064540; identities = 835 / 883 (95 %), no gaps), and Umbilicaria hypococcinea (strain A 12, GenBank JQ 739991; identities = 876 / 927 (94 %), eight gaps (1 %)). The closest hits using the SSU sequence are Cophinforma atrovirens (strain CSM _ 72, GenBank MF 436134; identities = 857 / 870 (99 %), no gaps), Gloeopycnis protuberans (specimen DAOM 745762, GenBank NG _ 067652; identities = 857 / 870 (99 %), no gaps), and Botryosphaeria mamane (strain CBS 117444, GenBank KF 531821; identities = 857 / 870 (99 %), no gaps). The closest hits using the rpb 2 sequence are Shiraia bambusicola (voucher SICAUCC 23-0005, GenBank OR 424351; identities = 237 / 283 (84 %), six gaps (2 %)), Lindra obtusa (strain AFTOL-ID 5012, GenBank FJ 238382; identities = 207 / 252 (82 %), three gaps (1 %)), and Natonodosa speciosa (strain CLM-RV 86, GenBank MH 745150; identities = 217 / 266 (82 %), six gaps (2 %)). In the case of SSU and rpb 2, the sequences of these two regions are not available for representatives of the most closely related genera, namely Beaucarneamyces and Pseudoarthrographis.