Strelitziomyces knysnanus Crous, in Crous et al., Persoonia 43: 303 (2019)

MycoBank number: MB 832894; Index Fungorum number: IF 832894; Facesoffungi number: FoF14955;

Etymology. Name refers to the location where it was collected, Knysna.

Mycelium consisting of hyaline, smooth, 1.5 – 2 µm diam hyphae. Conidiophores arising from superficial hyphae, erect, solitary, subcylindrical, 5 – 35 × 2 – 3 µm, hyaline to pale brown at base, 0– 3-septate, mostly unbranched, with terminal conidiogenous cells that are subcylindrical, hyaline, smooth, rarely pale brown, 5 – 25 × 2 – 2.5 µm, with terminal rachis of subdenticulate loci, 1– 2 × 0.5 –1 µm; loci truncate, not thickened nor darkened. Conidia solitary, hyaline, smooth, medianly 1-septate, fusoid, apex subobtuse, base truncate, 1 µm diam, (24 –)30– 32 × 2 µm. Sclerotium-like bodies formed prominently on and in agar, dark brown, muriformly septate, 30 – 80 µm diam, globose, lacking an ostiole, and remaining sterile although they are reminiscent of a coelomycete synasexual morph.

Culture characteristics — Colonies flat, spreading, with moderate aerial mycelium and smooth, lobate margin, reaching 10 mm diam after 2 wk at 25 °C. On MEA surface isabelline with diffuse isabelline pigment, reverse isabelline. On PDA surface smoke grey, reverse isabelline. On OA surface isabelline.

Typus — SOUTH AFRICA, Western Cape Province, Knysna, Knysna area, on leaves of Strelitzia alba (Strelitziaceae), 21 Nov. 2018, F. Roets, HPC 2727 (holotype CBS H-24183, culture ex-type CPC 37067 = CBS 146056.

GenBank accession numbers — ITS: MN562135.1, LSU: MN567642.1, rpb2: MN556810.1.

Notes — Strelitziomyces is closely related to Anungitiomyces, a monotypic genus occurring on Eucalyptus leaf litter in South Africa (Crous et al. 2019a). Anungitiomyces is characterised by brown, erect conidiophores, 0 –1-septate, obclavate, hyaline conidia, arising via sympodial conidiogenesis. The main differences between the two genera lie in the lack of pigmentation in Strelitziomyces, and the prominently formed sclerotium- like bodies.

Based on a megablast search of NCBIs GenBank nucleotide database, the closest hits using the ITS sequence had highest similarity to Anungitiomyces stellenboschiensis (strain CPC 34726, GenBank MK876376.1; Identities = 537/616 (87 %), 31 gaps (5 %)), Rhinocladiella pyriformis (strain CBS 469.94, GenBank MH862476.1; Identities = 379/434 (87 %), 15 gaps (3 %)), and Pseudotruncatella arezzoensis (strain MFLUCC 14-0988, GenBank NR_157489.1; Identities = 352 /399 (88 %), 19 gaps (4 %)). Closest hits using the LSU sequence are Anungitiomyces stellenboschiensis (strain CPC 34726, GenBank MK876415.1; Identities = 810/ 826 (98 %), 1 gap (0 %)), Oxydothis garethjonesii (strain MFLUCC 15-0287, GenBank KY206762.1; Identities = 804/837 (96 %), 4 gaps (0 %)), and Entosordaria quercina (strain RQ, GenBank MF488994.1; Identities = 800/837 (96 %), 4 gaps (0 %)). No significant hits were obtained when the rpb2 sequence was used in blastn and megablast searches.