Bisifusarium phloginum K. Zhang & Crous 2025, sp. nov.

Bisifusarium phloginum K. Zhang & Crous, sp. nov. MB 858742. Fig. 10. Etymology: Name refers to Phlox, the host genus from which it was isolated. Sporodochia greyish orange, formed abundantly on CLA. Sporodochial conidiophores verticillately branched and densely packed, subulate to subcylindrical, septate, 13–17 × 2–4 µm, smooth- and thin-walled. Sporodochial macroconidia slender, falcate, slightly curved with almost parallel sides, tapering slightly towards both ends, with a papillate to hooked, curved apical cell and a blunt to poorly developed foot-like basal cell, 1-septate, hyaline, smooth- and thin-walled, (13.6–)15.5–18.0(–20.9) × (2.0–)2.3–2.8(–3.0) µm. Chlamydospores intercalary, globose to ellipsoid, solitary or in chains. Culture characteristics: Colonies in the dark for 7 d at 25 °C: on OA reaching 3–3.5 cm diam., raised, aerial mycelia dense, colony margin entire, surface and reverse pale orange. Colonies on PDA reaching 3–3.5 cm diam., raised, aerial mycelium dense, colony margin erose, surface and reverse white, orange at the centre. Colonies on SNA reaching 3–4 cm diam., flat, aerial mycelium scant, colony margin erose, surface and reverse white; odour absent. Typus: Germany, from Phlox drummondii, collection date and collector unknown (holotype CBS H-25448, culture ex-type CBS 110137 = BBA 64304). Additional material examined: Germany, from Phaseolus vulgaris, collection date and collector unknown, culture CBS 110142 = BBA 71614. Notes: Bisifusarium phloginum is phylogenetically closely related to B. penicilloides and B. salinasense, from which it differs by 68 bp (ITS 2, rpb2 17, tef1 28, and tub2 21 bp) and 47 bp (ITS 2, rpb2 8, tef1 27, and tub2 10 bp), respectively. Morphologically, B. phloginum is distinguished by its slender, falcate, slightly curved macroconidia with almost parallel sides, a papillate to hooked apical cell, and a blunt to poorly developed foot-like basal cell. This is in contrast to those of B. penicilloides that are ellipsoidal, straight or curved, lunate or reniform with distinct foot-like basal cells (Savary et al. 2021), or the more robust macroconidia of B. salinense.