Oidiosporium botulisporum Sastoque, Cano & Stchigel 2025, sp. nov.

Oidiosporium botulisporum Sastoque Cano & Stchigel, sp. nov. MycoBank MB 847921. Fig. 5. Etymology: From Latin botulus -, sausage, and - spora, spore, because the shape of the thallic conidia. Typus: Spain, Canary Islands, La Palma, Fuencaliente (Los Canarios), isolated from soil of Teneguía volcano, 15 Jul. 2008, coll. M. Calduch & A.M. Stchigel, isol. A.P. Sastoque (holotype CBS H-24247, culture ex-type FMR 18828 = CBS 149964). On oatmeal agar after 4 wk at 25 °C: Mycelium abundant, composed of hyaline to brown or reddish-brown, septate, branched, smooth- and thin- to moderately thick-walled hyphae when pigmented, 1–4.5 μm wide, often coiled (Fig. 5F). Conidiophores absent. Conidia holothallic, aseptate, hyaline or brown to reddish-brown, smooth- and thin-walled to moderately thick-walled, guttulate, subglobose, ellipsoidal, broadly fusiform, barrel-shaped or sausage-shaped, 8–23 × 4–8 μm, flattened at both ends but without visible scars, formed by remodelling of pre-existing hyphae sections, secession schizolytic (Fig. 5G), produced in short to long chains (Fig. 5F–H). 1 CBS, Westerdijk Fungal Biodiversity Institute, fungal and yeast collection (Utrecht, The Netherlands). CGMCC, China General Microbiological Culture Collection Centre (Beijing, China). COAD, Coleção Octávio Almeida Drummond, Universidade Federal de Viçosa (Viçosa, Brazil). FMR, Faculty of Medicine-Reus culture collection (Reus, Spain). IRAN…C, Iranian Fungal Culture Collection, Iranian Research Institute of Plant Protection (Tehran, Iran). T Ex-type strain. NT Ex-neotype strain. Culture characteristics (after 7 d at 25 ° C): Colonies on PCA 11–13 mm diam., flat and circular; margin filamentous and regular; surface sand (4B3) with a thin layer of greyish brown (6F3) aerial hyphae in the central area and yellowish white (4A2) margins; soluble pigment absent; reverse pale yellow (4A3) and light yellow in the centre (4A4). Colonies on OA 27–28 mm diam., flat and circular; margin filamentous and regular; surface champagne (4B4) with sparse dark grey (6F3), radiated and superficial mycelium and pale yellow (4A3) margins; soluble pigment violet brown (10F6) after 10 wk (Fig. 6E); reverse like surface. Colonies on CMA 13–14 mm diam., flat and circular; margin filamentous and regular; surface black (6F3) with sparse brownish grey (6F2) aerial mycelium and olive green (2F6) margins; soluble pigment absent; reverse greyish brown (5F3). Colonies on MEA 15–16 mm diam., flat and circular; margin filamentous and regular; surface with a thin layer of pearl white (3B1) and short aerial mycelium; reverse with olive grey (2F2) margins. Culture iconography after 4 wk of incubation on PCA, OA, CMA and MEA (Fig. 5A–D, respectively). Minimum, optimum and maximum temperature of growth on PDA after 7 d: 15 °C, 25 °C and 37 ºC, respectively. Notes: Oidiosporium botulisporum was placed in a fully supported clade close to the type species of the genera Carteria and Thermocarpiscus, but as a distinct genus (Fig. 1). The new genus differs from the latter two by producing an asexual morph consisting of chains of holothallic conidia, whereas C. arctostaphyli and T. australiensis lack asexual morphs (Wang et al. 2019a, 2022).