Aspicilia polychroma Anzi Cat. Lich. Sondr.

Szczepańska, Katarzyna, Kukwa, Martin, Guzow-Krzemińska, Beata & Urbaniak, Jacek, 2023, New and rare lichens of the family Megasporaceae discovered in Poland, Phytotaxa 598 (2), pp. 133-144 : 136-138

Aspicilia polychroma Anzi Cat. Lich. Sondr. : 59. 1860.

≡ Lecanora polychroma (Anzi) Nyl. , in Stizenberger, Ber. Tätigk. St. Gallischen Naturwiss. Ges.: 379. 1882.

( Fig. 1B )

Thallus lichenized, crustose, rather thick, irregularly cracked to areolate or verrucose-areolate, dark grey, browngrey, often with olive or yellowish tinge, matt. Areoles flat to slightly convex, angular, smooth, 0.5–2.5 mm in diam. Prothallus rarely visible, fibrous, dark grey. Apothecia immersed, 1 to 5 per areole, 0.5–1.2 mm in diam., thalline margin same colour as the thallus or darker, thin, disc rounded to irregular, black, flat and matt. Hymenium colourless, 90–130 μm tall, with submoniliform paraphyses (3–5 globose apical cells), epihymenium green-brown to olive-brown, N+ green intensifying, K+ yellowish brown (Caesiocinerea-green), hypothecium colourless.Asci 8-spored, ascospores hyaline, simple, narrowly ellipsoid, 18–23 × 8–13 μm. Conidia filiform 15–24 × 1 μm.

Chemistry: No secondary metabolites were detected in the analysed material.

Ecology and distribution: Aspicilia polychroma is a rare, mountain species occurring mainly in Europe, especially in the Alps, the Karpaty Mts and the Pyrenees. It has been reported from Austria, Finland, France, Germany, Italy, Norway, Portugal, Slovakia, Spain and Switzerland ( Vitikainen et al. 1997; Llimona & Hladun 2001; Lisická 2005; Roux 2012; Wirth et al. 2013; Flakus 2014; Nimis et al. 2018; Westberg et al. 2021; Nimis & Martellos 2022), as well as USA and Canada ( Esslinger 2016). In Poland, only a variety A. polychroma var. rubrireagens Asta & Cl. Roux , in which the thallus reacts K+ red, has been reported from a single locality in the High Tatry Mts ( Flakus 2007). The new records represent the typical variety without lichen substances.

Aspicilia polychroma prefers slightly calciferous, siliceous rocky habitats in open and well-lit locations.All newly recorded specimens were found growing at altitudes above 700 m, on boulders in neutrophilic habitats surrounded by pastures or meadows.

Notes: Aspicilia polychroma may be confused with other taxa of the Megasporaceae family, especially Aspicilia calcitrapa Cl. Roux & A. Nordin , Circinaria gibbosa (Ach.) A. Nordin, Savić & Tibell , C. caesiocinerea (Nyl. ex Malbr.) A. Nordin, Savić & Tibell and Sagedia zonata Ach. , all of which also occur on siliceous rocks in open places, and all with thalli showing no colour reaction with standard spot tests ( Owe-Larsson et al. 2007; Fletcher et al. 2009; Roux et al. 2011; Wirth et al. 2013). The main distinguishing feature of A. polychroma is, however, the length of the conidia, which are clearly longer than in the mentioned taxa. In addition, A. gibbosa and C. caesiocinerea produce larger ascospores (20–26[–30] × 12–16[–18] μm) and, additionally, C. caesiocinerea contains aspicilin as a secondary metabolite in the thallus ( Owe-Larsson et al. 2007; Fletcher et al. 2009; Wirth et al. 2013).

Material examined: POLAND. Dolnośląskie province: Sudety Mts, Sowie Mts, Sokola Pass , elev. c. 800 m, on a siliceous boulder in the meadow, 11 April 2015, K. Szczepańska 1022 (Hb. Szczepańska) ; Małopolskie province: Karpaty Mts, Beskid Sądecki Mts, Jaworzyna Krynicka Range , Zadnie Góry settlement, elev. c. 850 m, on sandstone rocks, 4 July 1989, L. Śliwa (KRA-396); Jaworzyna Krynicka Range, Zadnie Góry settlement, elev. c. 790 m, on sandstone rocks, 4 July 1989, L. Śliwa (KRA-397); Jaworzyna Krynicka Range, Sarnica Mt, elev. c. 920 m, on sandstone rocks, 4 Aug. 1989, L. Śliwa (KRA-398); Karpaty Mts , Beskidy Zachodnie Mts , Gorce Mts , by the black tourist trail in the Jastrzębie clearing at the edge of the Gorce National Park , elev. 960 m, on sandstone rock, 22 October 1997, P. Czarnota, J. Kiszka (GPN-1895/94).

Figures

FIGURE 1. Specimens treated.A. Aspicilia goettweigensis (Hb. Szczepańska 1093). B. Aspicilia polychroma (Hb. Szczepańska 1022). C. Aspicilia verrucigera (Hb. Szczepańska 1272). D. Oxneriaria supertegens (KRAM L-34348). E. Sagedia mastrucata (Hb. Szczepańska 1186). F. Sagedia zonata (KRAM L-42336). Scales: 2 mm. Fot. K. Szczepańska.