Bisifusarium africanum K. Zhang & Crous, 2025

Bisifusarium africanum K. Zhang & Crous , sp. nov. MB 858737 View Materials . Fig. 3.

Etymology: Name refers to Africa, the continent where it was collected.

Sporodochia orange, formed abundantly on SNA and CLA. Sporodochial conidiophores verticillately branched and densely packed, giving rise to 1–6 conidiogenous cells, 10– 35 × 3–5 µm; sporodochial phialides monophialidic, subulate to subcylindrical, smooth- and thin-walled, 2–4 µm diam. 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, 2-septate, with septa a third up from hilum and down from apex, not median, hyaline, smooth- and thin-walled, (27.2–)28.0–29.0(–30.4) × (3.2–)3.5–3.9(–4.1) µm. Microconidia not observed. Chlamydospores intercalary, solitary or in short chains, ellipsoid to cylindrical, 4–8 µm diam.

Culture characteristics: Colonies in the dark for 7 d at 25 °C: on OA reaching 7–7.5 cm diam., raised, aerial mycelia dense, colony margin entire, surface and reverse white. Colonies on PDA reaching 7.5–8 cm diam., raised, aerial mycelium dense, colony margin erose, surface and reverse white. Colonies on SNA reaching 7–7.5 cm diam., flat, aerial mycelium scant, colony margin erose, surface and reverse white; pigment and odour absent.

Typus: South Africa, Gauteng Province, from Encephalartos sp. leaf, Mar. 2018, P.W. Crous (holotype CBS H-25455 , culture ex-type CBS 153387 View Materials = CPC 34902 View Materials ); ibid., culture CPC 34903 View Materials .

Notes: Bisifusarium africanum clusters within a fully supported clade containing B. biseptatum , B. colchici , B. penzigii and B. solicola ; all phylogenetically well-separated species. Bisifusarium africanum differs from B. biseptatum by 36 bp in the combined alignment (ITS 9, rpb2 5, tef1 12 and tub2 10 bp), from B. colchici by 15 bp (ITS 1, rpb2 6 and tef1 8 bp, while no tub2 sequences are available B. colchici ), from B. penzigii by 24 bp (ITS 2, rpb2 6, tef1 10, and tub2 6 bp), and from B. solicola by 17 bp (ITS 0, rpb2 2, tef1 11, and tub2 4 bp). Morphologically, B. africanum is similar to B. biseptatum , but can be distinguished from that species based on macroconidial septation (2-septate in B. africanum vs 0–1-septate in B. biseptatum ), macroconidial shape (macroconidial ends equally hooked in B. biseptatum in contrast to more strongly apically hooked in B. africanum ), and the absence of microconidia, which are present in B. biseptatum ( Schroers et al. 2009) .