Cytosporella fuligomixta Piątek, Stryjak-Bogacka & Czachura, 2025

Cytosporella fuligomixta Piątek, Stryjak-Bogacka & Czachura sp. nov.

Figs 2 View Figure 2 , 3 View Figure 3 , 4 View Figure 4

Etymology.

Name refers to the isolation of this fungus from sooty mould communities.

DNA barcodes.

ITS (PQ 001666), LSU (PQ 001665), mtSSU (PP 999744), rpb 2 (PP 997507) and tef 1 (PP 997508).

Typus.

Poland • Małopolska Province, Kraków County: Kraków-Czyżyny (Park Lotników), municipal greenery (city park) , isolated from sooty mould community on Quercus robur leaves, 10 Oct. 2018, leg. M. Piątek, W. Bartoszek & P. Czachura (holotype KRAM F -59995 ; culture ex-type G 107 = CBS 152343 ) .

Description.

Mycelium composed of sparsely branched, septate, hyaline, straight to curved, thin-walled hyphae, 1.0–1.5 µm wide; sometimes with swellings, 2.0–3.0 µm wide. Hyphae sometimes anastomose, intertwine or form fascicles [description on MEA]. Conidiomata flat, erumpent, separate, eustromatic, brown, disintegrating at the top during maturation, up to 500 µm diam, exuding a creamy conidial mass, partly enclosed by a wall of greenish-olive textura angularis. Conidiophores reduced to conidiogenous cells lining the inner cavity, hyaline, smooth, ampulliform or subcylindrical, phialidic, 3.5–8 × 3–5 µm. Conidia solitary, aseptate, hyaline, smooth, cylindrical, rarely slightly allantoid, apex obtuse, base bluntly rounded, (4 –) 5–8.5 × 2–2.5 (– 3) µm [description on OA].

Culture characteristics.

Colonies on MEA erumpent, spreading, convex, rosaceous, reaching 4 mm diam after 2 weeks at 6 ° C, 9 mm diam after 2 weeks at 15 ° C and 6 mm diam after 2 weeks at 25 ° C, reaching 6 mm diam after 4 weeks at 6 ° C, 18 mm diam after 4 weeks at 15 ° C and 8 mm diam after 4 weeks at 25 ° C, surface cerebriform, with sparse aerial mycelium, margin finely crenate. Reverse rosaceous. Colonies on PDA erumpent, spreading, umbonate, slimy rosaceous, reaching 4 mm diam after 2 weeks at 6 ° C, 11 mm diam after 2 weeks at 15 ° C and 4 mm diam after 2 weeks at 25 ° C, reaching 7 mm diam after 4 weeks at 6 ° C, 20 mm diam after 4 weeks at 15 ° C and 7 mm diam after 4 weeks at 25 ° C, surface with radial furrows starting from centre towards margin, with sparse aerial mycelium, margin finely crenate. Reverse rosaceous. Colonies on OA spreading, flat, rosaceous, reaching 4 mm diam after 2 weeks at 6 ° C, 10 mm diam after 2 weeks at 15 ° C and 5 mm diam after 2 weeks at 25 ° C, reaching 8 mm diam after 4 weeks at 6 ° C, 22 mm diam after 4 weeks at 15 ° C and 5 mm diam after 4 weeks at 25 ° C, surface with indistinct radial furrows starting from the centre towards the margin, without aerial mycelium, margin entire. Reverse rosaceous.

Notes.

Cytosporella fuligomixta is well delimited morphologically and ecologically from four other Cytosporella species described on Quercus hosts. These are Cytosporella mendax , C. pisiformis , C. quercus and C. sphaerosperma . All of them were described from branches or wood of Quercus sp. or Quercus robur and differ from C. fuligomixta in shape and sizes of conidia. The conidia are globose-ellipsoid, hyaline, 4–5 × 3.5–4 µm in C. mendax ( Saccardo 1884; Saccardo and Roumeguère 1884), globose, yellowish, 3–4 µm in C. pisiformis ( Saccardo 1884) , perfectly globose, hyaline, 9–12 µm in C. quercus ( Saccardo and Sydow 1902) , and globose and hyaline in C. sphaerosperma ( Saccardo 1884) .

Other than being phylogenetically distinct, Cytosporella fuligomixta differs also morphologically from three sequenced species of this genus: C. calamagrostidis , C. chamaeropis and C. juncicola ( Crous et al. 2019 b, 2024). Cytosporella calamagrostidis described from old leaves of Calamagrostis arenaria has slightly shorter conidia, (5 –) 6–7 µm long ( Crous et al. 2024), C. chamaeropis described from rotten Chamaerops humilis has globose conidia ( Passerini 1888) and C. juncicola described from culms of Juncus effusus has slightly shorter and narrower conidia, (4 –) 5–6 (– 7) × 2 µm ( Crous et al. 2019 b).