Spirographa skorinae Tsurykau, Brackel, Flakus & Kukwa  sp. nov.

Index Fungorum number: IF 901387; Mycobank number: MB 901387; Facesoffungi number: FoF 16055; Fig. 1

Etymology – Named after Francisk Skorina, Belarusian and East Slavic first printer, scientist, first professional educator, teacher, writer and linguist due to his significant contribution to the development of science, education, Belarusian language and literature, and the whole culture of the Belarusian and East Slavic people, on the occasion of his 535th anniversary and quincentenary Belarusian book printing.

Holotype – M-0330700

Parasitic on the thallus of corticolous lichen Polycauliona polycarpa. Sexual morph Not observed. Asexual morph Coelomycetous (“Cornutispora”-type). Mycelium immersed in the host thallus, hyaline. Conidiomata pycnidial, scattered or in groups of 2–3, initially immersed, becoming partially erumpent, black when dry, pale brown to almost hyaline when wet, globose, (65–)80–135(–150) μm in diam. (n=16), opening by the disintegration of the upper wall; ostiole absent. Pycnidial wall paraplectenchymatic, composed of several layers of cells, pale brown at the top, hyaline at the base. Conidiophores hyaline, septate, branched, thin-walled, up to 35 μm long, arising from the innermost cell layer lining the pycnidial cavity. Conidiogenous cells hyaline, thin-walled, polyblastic, sympodial or synchronous, terminal to lateral, producing few conidia from minute loci. Conidiogenesis holoblastic. Conidia hyaline, aseptate, triangular (Y-shaped), composed of a thick main axis with truncate base, (7.5–)8.4–11.7(–14.5)×(2.0–)2.1–2.7(–3.0) μm, (x̄=10.1, SD =1.7, n=37; x̄=2.4, SD =0.3, n=37), with a narrow appendage arising from the truncate base, (2.0–)2.8–4.8(–6.0) μm and two gradually tapering divergent arms, (7.0–)8.0–10.8(–13.0)×(1.5–)1.8–2.4(–3.0) μm (x̄=9.4, SD=1.4, n=37; x̄=2.1, SD=0.3, n=37).

Material examined – Spirographa skorinae: Germany, Bavaria, Mittelfranken, Kreis Erlangen-Höchstadt, northern slope of the Kalchreuther Höhe, orchard, on twigs of Prunus avium, 49° 33′ 51.8″ N, 11° 07′ 18.0″ E, 370 m, on Polycauliona polycarpa, 15 October 2007, W. v. Brackel (M-0330700, holotype; GSU 2196, hb Brackel, isotypes); Bavaria, Mittelfranken, Kreis Erlangen-Höchstadt, Kalchreuther Höhe, orchard, on twigs of Prunus avium, 49° 33′ 23.8″ N, 11° 06′ 34.4″ E, 390 m, on Polycauliona polycarpa, 22 October 2007, W. v. Brackel (hb Brackel, paratype); BELARUS, Gomel region, Gomel district, the city of Gomel, close to Zhemchuzhnaja str., 52° 21′ 30″ N, 31° 01′ 35″ E, on corticolous Polycauliona polycarpa, 12 July 2019, A. Kavalenka s.n. (KRAM 73133, paratype); POLAND, Kotlina Biebrzańska, Biebrzański National Park, c. 8 km NW of Trzcianne village, Budy village, 53° 23′ 17″ N, 22° 34′ 28″ E, on Polycauliona polycarpa on branch of Syringa vulgaris, 16 September 2005, M. Kukwa, E. Bylińska, M. Seaward (UGDA L-12918, paratype). – Spirographa cf. lichenicola: Bolivia, Dept. Tarija, Prov. Aniceto Arce, close to la Mamora between Tarija and Bermejo, 22° 09′ 51″ S, 64° 40′ 03″ W, 1320 m, disturbed Tucumano-Boliviano Forest with Tillandsia, on corticolous Ochrolechia sp., 27 July 2015, A. Flakus 27,320 (KRAM, LPB).

GenBank numbers – Spirographa skorinae KRAM-L 73133 (paratype): ITS = OQ054789, LSU = OQ048258; Spirographa cf. lichenicola A. Flakus 27320 (KRAM): ITS=OQ054793, LSU=OQ034609.

Notes – The new species resembles Spirographa intermedia in its somehow similar conidial shape and dimensions. However, the latter can be differed from S. skorinae by having larger pycnidia, (102–)150–160(–170) μm in diam., thinner main axis (2–2.5 μm wide) and different host preference (Ochrolechia spp.) (Punithalingam 2003; Flakus et al. 2019). Moreover, the shape of shorter divergent arms is different: in S. skorinae they gradually taper towards the end in the majority of conidia, whereas in S. intermedia the divergent arms have usually swollen bases (3–4 μm long) and distinct narrow appendages (3.5–4.5 μm long) (Punithalingam 2003). Measured over the whole length (including the appendages) the divergent arms are shorter in S. intermedia (up to c. 8.5 μm when measurements taken from Punithalingam 2003) than in the new species.

Figure 1 – Spirographa skorinae (KRAM 73133, paratype). a Habitus, showing six pycnidia immersed in the host thallus (two overmature pycnidia at the bottom of the picture are empty). b–e Conidia, in water. Scale bars: a=100 µm, b–e=10 µm