Gyrothrix anomianthi N.I. de Silva, Lumyong & K.D. Hyde, in de Silva, Hyde, Lumyong, Phillips, Bhat, Maharachchikumbura, Thambugala, Tennakoon, Suwannarach & Karunarathna, Mycosphere 13(1): 1051 (2022)

Index Fungorum number: IF 559526, Facesoffungi number: FoF 10723; Fig. 1

Etymology: Name reflects the host genus Anomianthus, from which the new species was isolated.

Holotype – MFLU 21-0219

Saprobic on dead twigs attached to Anomianthus dulcis. Sexual morph: Undetermined. Asexual morph: Mycelium 1–2.5 µm diam., hyaline, branched, septate, smooth hyphae. Setae 70–130 µm long, 2–3 µm diam., brown, subcylindrical, erect, multiseptate, thick-walled, verruculose to warty, apex spirally curved, apical region frequently with curved lateral branches, base bulbous. Conidiophores reduced to conidiogenous cells. Conidiogenous cells 7–12 × 3–4 μm, holoblastic, hyaline, ampulliform to lageniform. Conidia 10–13 × 1.5–3 µm ( = 12 × 2 µm, n = 30), hyaline, fusoid, inequilateral, inner plane flat, outer plane convex, apex subobtuse, base truncate, aseptate, smooth.

Culture characteristics – Colonies on PDA reaching 25 mm diameter after 2 weeks at 25 °C, colonies from above circular, margin lobate, flat, with moderate aerial mycelium, light grey; reverse: dark grey.

Material examined – THAILAND, Chiang Rai Province, dead twigs attached to the host plant of Anomianthus dulcis (Annonaceae), 4 April 2019, N. I. de Silva, AND20 (MFLU 21-0219, holotype), ex-type living culture, MFLUCC 21-0200.

Notes – During our investigation of microfungi from Anomianthus dulcis plants, a hyphomycetous fungus was recovered that is characterized by superficial, effuse, grayish brown, velvety, stromatic colonies with brown, repeatedly branched erect setae. This new isolate (MFLUCC 21-0200) constituted an independent lineage basal to Gyrothrix encephalarti (CPC 35966) and G. eucalypti (CPC 36066) in phylogenetic analyses of combined LSU, ITS, tef1 sequence data with 81% ML, 1.00 BYPP statistical support. Forty-eight base pair differences between the new isolate (MFLUCC 21-0200) and G. encephalarti (CPC 35966) and 50 base pair differences between the new isolate (MFLUCC 21-0200) and G. encephalarti (CPC 36066) were detected in ITS (500 bp) nucleotide sequences. The new collection (MFLU 21-0219) (10–13 × 1.5–3 µm) has slightly smaller conidia than Gyrothrix encephalarti and G. eucalypti. Conidia of G. encephalarti is 7–14 × 3–3.5 µm (Crous et al. 2020) and those of G. eucalypti is 8–15 × 2–2.5 µm (Crous et al. 2019). Coupled with morphology and phylogeny, we here introduce G. anomianthi as a novel species from Anomianthus dulcis in Thailand.

Figure 1. Gyrothrix anomianthi (MFLU 21-0219, holotype). a–c Specimen. d–f Setae. g Conidiogenous cells integrate into the branch tips of the setae. h–k Conidia. Scale bars: a = 500 μm, b = 200 μm, c = 100 μm, d–f = 20 μm, g = 10 μm, h–k = 5 μm.