Pseudohumicola intercalarispora Sastoque, Stchigel & Cano, 2025

Pseudohumicola intercalarispora Sastoque, Stchigel & Cano View in CoL , sp. nov. MycoBank MB 847821. Fig. 10 View Fig .

Etymology: From Latin intercalaris -, intercalary, and - spora, spore, due to the presence of holothallic intercalary conidia.

Typus: Spain, Canary Islands, La Palma, Fuencaliente (Los Canarios), from soil of Teneguía volcano, 15 Jul. 2008, coll. M. Calduch & A.M. Stchigel, isol. A.P. Sastoque (holotype CBS H-25245, culture ex-type FMR 19235 View Materials = CBS 149962 View Materials ) .

On potato carrot agar after 2 wk at 25 °C: Mycelium composed of hyaline, septate, branched, smooth- and thin-walled, 1–2.5 μm wide hyphae, often forming spirals ( Fig. 10E View Fig ). Conidiophores undifferentiated. Conidiogenous cells integrated to the vegetative hypha. Conidia mostly holoblastic and 1-celled, solitary or less frequently in chains of two, sessile, on short conical denticles or on short side branches from the hyphae ( Fig. 10E,F View Fig ), smooth- and thick-walled, covered by mucilaginous and dark brown substance, becoming verrucose to reticulate when old ( Fig. 10F View Fig ), sometimes intercalary (holothallic) ( Fig. 10F View Fig ), then 1-celled, pale olivaceous brown to brown with dark brown walls, globose, subglobose, obovoid, pyriform, less frequently ovoid, obpyriform or ellipsoidal, (4–)7–9(–10) × (4–)7–10(– 11) μm ( Fig. 10E, F View Fig ). Acremonium-like synasexual morph and sexual morph not observed.

Culture characteristics (after 7 d at 25 ° C): Colonies on PCA 20–30 mm diam., circular and flat; margin filamentous, regular to lobulated; surface showing white (6A1) aerial mycelium in the central area, surrounded by a brownish-grey (6F2) circle and with yellowish-white (4A2) narrow or wide margins; soluble pigment absent; reverse brownish-grey (6F2) to brown (6E5) with yellowish-white margins (4A2). Colonies on OA 29–33 mm diam., flat, circular, and expansive; margin filamentous and regular; surface with scarce and floccose grey (6E1) aerial hyphae only in the centre, bottom brownish grey (5F2) and margins bronze (5E5) without aerial hyphae; soluble pigment absent; reverse greyish brown (5F3) and margins hair brown (5E4). Colonies on CMA 22–23 mm diam., circular and flat; margin filamentous and regular; surface chocolate (6F4) with floccose greyish white (6B1) aerial hyphae in the central area, around and margins brown (5F6); soluble pigment absent; reverse chocolate (6F4) in the centre and wide tobacco (5F6) margins. Colonies on MEA 28–30 mm diam. after 7 d at 25 °C; flat and circular; margin entire and regular; surface brownish orange (6C3) with white (6A1) aerial hyphae in the centre, sand (4B3) and with yellowish-white (4A2) margins; soluble pigment absent; reverse pale orange (6A3) in the centre, surrounded by greyish-orange (5B3) and margins orange-white (5A2). Culture iconography after 2 wk of incubation on PCA, OA, CMA and MEA ( Fig. 10A–D View Fig , respectively). Minimum, optimum and maximum temperature of growth on PDA after 7 d: 12 °C, 30 °C and 37 °C, respectively.

Notes: Pseudohumicola intercalarispora was placed as a distinct species in a basal branch of a well-supported clade (1 PP/99 % BS) including Pseudohumicola alba COAD 3126 ( Fig. 1 View Fig ). Pseudohumicola intercalarispora differs from P. alba by the presence of abundant intercalary conidia (absent in P. alba ) and by the absence of an phialidic synasexual morph (present in P. alba ) as well as the shape and size of humicolalike conidia [globose, subglobose, obovoid, pyriform, less frequently ovoid, obpyriform or ellipsoidal, (4–)7–9(–10) × (4–)7–10(–11) μm in P. intercalarispora and globose to subglobose or obovoid, with a truncated base, (8.3–)9.6–10.4(– 12.6) × (7.0–)8.8–9.6(–10.4) μm in P. alba ] ( Oliveira et al. 2023).