Pulchrospora resinae Czachura & Janik 2025, sp. nov.

Pulchrospora resinae Czachura & Janik sp. nov. Figs 5, 6 Etymology. The name refers to the habitat of this species. Typus. Poland, Podkarpackie Province, Krosno County, the Modrzyna Reserve, isolated from the resin of Abies alba, 21. Jun. 2021, leg. P. Czachura (holotype: KRAM F-60003; culture ex-type: CBS 152413). Description. Mycelium consisting of branched, septate, hyaline, smooth hyphae, 1.5–5.5 µm diam., with frequent anastomoses. Aerial conidiophores arising laterally or terminally from somatic hyphae, 16.8–68.4 μm long, unbranched or branched, hyaline, smooth- and thin-walled, bearing terminal and lateral conidiogenous cells, or more commonly reduced to single conidiogenous cells borne laterally or terminally on aerial hyphae. Conidiogenous cells monophialidic, subcylindrical, cylindrical or slightly subulate, hyaline, smooth- and thin-walled, 16.8–48.5 μm long, at the base 2.2–3.6 μm wide and at the apex 1.3–2.0 μm wide, often with conspicuous flared collarettes, without noticeable periclinal thickening. Microconidia forming small false heads, ellipsoidal, cylindrical, slightly reniform or obovoid, hyaline, smooth- and thin-walled, aseptate or rarely 1 - septate, 3.8–21.6 × 2.4–4.5 μm. Sporodochial conidiophores densely packed, irregularly and verticillately branched, bearing lateral and terminal solitary monophialides. Sporodochial conidiogenous cells monophialidic, slightly subulate to subcylindrical, hyaline, smooth-walled, 17.2–32.2 μm long, at the base 2.4–3.3 μm wide and at the apex 1.5–2.2 μm wide, collarettes absent or inconspicuous, without noticeable periclinal thickening. Sporodochial macroconidia falcate, slightly curved to curved with parallel walls, regularly wide along almost the entire length, tapering in apical cell toward the apex (rarely tapering towards both ends), apical cell slightly curved to curved, basal cell obtuse, non-foot-shaped, 1–5 - septate (rarely aseptate or 6–7 - septate), hyaline, smooth, 14.3–44.8 × 3.1–4.8 μm. Culture characteristics. Colony on MEA umbonate with slightly undulate margin, rosy buff with white aerial mycelium, reaching 12 mm diam. after 2 weeks at 15 ° C and 19 mm diam. after 2 weeks at 25 ° C, reverse pale buff. Colony on OA flat with crenate margin, whitish, reaching 18 mm diam. after 2 weeks at 15 ° C and 25 mm diam. after 2 weeks at 25 ° C, reverse whitish to slightly pale yellow. Colony on PDA umbonate with slightly undulate margin, pale buff to pale rosy buff, reaching 11 mm diam. after 2 weeks at 15 ° C and 22 mm diam. after 2 weeks at 25 ° C, reverse pale buff. Colony on SNA flat with crenate margin, whitish, reaching 11 mm diam. after 2 weeks at 15 ° C and 21 mm diam. after 2 weeks at 25 ° C, reverse whitish. Additional specimens examined. Poland, Podkarpackie Province, Krosno County, the Modrzyna Reserve, isolated from the resin of Abies alba, 22. Jun. 2021, leg. P. Czachura (KRAM F-60004; culture CBS 152414); Poland, Podkarpackie Province, Krosno County, the Modrzyna Reserve, isolated from the resin of Picea abies, 23. Oct. 2020, leg. P. Czachura (KRAM F-60005; culture CBS 152415); Poland, Świętokrzyskie Province, Kielce County, the Świętokrzyski National Park, the strict protection area Psarski Dół, isolated from the resin of Picea abies, 16. Oct. 2020, leg. P. Czachura (KRAM F-60006; culture CBS 152416). Notes. Pulchrospora resinae gen. et sp. nov. is phylogenetically closest to the genera Cosmospora, Cosmosporella, Dialonectria and Pseudocosmospora. All these genera formed the highly supported clade (MLB = 99 %, BPP = 1) but with unresolved relationship between genera in this group (Fig. 2). Pulchrospora resinae produces micro- and macroconidia similarly to Dialonectria and Cosmosporella. However, P. resinae produces microconidia on aerial conidiophores and macroconidia are produced on sporodochial conidiophores, like in the genus Dialonectria, but differently from the genus Cosmosporella whose members produce micro- and macroconidia on aerial conidiophores (Huang et al. 2018; Crous et al. 2021; Perera et al. 2023). Moreover, the general morphology of macroconidia between these genera differs significantly. Macroconidia of P. resinae are characterised by being regularly wide along almost the entire length, tapering toward the apex (mostly) and obtuse, non-foot-shaped base, in contrast to members of Dialonectria and Cosmosporella, whose macroconidia are characterised by slightly tapering towards both ends and having foot-shaped basal cells (Crous et al. 2021). Additionally, macroconidia of Cosmosporella are commonly irregularly wide and longer (50–90 μm) than macroconidia of P. resinae which measured 14.3–44.8 μm (Gerlach and Nirenberg 1982; Crous et al. 2021).