Aspicilia goettweigensis (Zahlbr.) Hue

Nouv. Arch. Mus. Hist. Nat., Paris, 5 ser. 2(1): 112. 1910 ≡ Lecanora goettweigensis Zahlbr., Ann. Naturhist. Mus. Wien 20: 345. 1905. Fig. 1A.

Thallus lichenized, crustose, squamulose-areolate, olive-brown to olive-grey, matt. Areoles thin, flat and smooth at the margin of the thallus to thick and forming small squamules in the centre. Squamules irregular, white pruinose on the edges, partially erected and overlapping, convex and ear-shaped with medulla visible from underneath, 0.5–0.8 mm in diam. Prothallus rarely visible, fibrous, dark olive-grey. Apothecia rare, immersed, 1 to 3 per areole, 0.2–1.0 mm in diam., thalline margin same colour as the thallus, thin, white pruinose and radially incised on the inside edge, disc black, rounded, flat and matt. Hymenium colourless, 80–100 μm tall with submoniliform paraphyses (3–4 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, 18–25 × 8–12 μm. Conidia filiform, 14–20 × 1 μm.

Chemistry: According to Paukov et al. (2016), A. goettweigensis contains stictic acid (major) with norstictic and connorstictic acids (both minor) in the medulla. One Polish specimen lacked secondary substances (Hb. Szczepańska 1333), but the BLAST analyses of the nucITS rDNA sequence undoubtedly identified it as A. goettweigensis (see below).

Ecology and distribution: Aspicilia goettweigensis is a rare and poorly known species that has been recorded from only a few European countries, including Austria, the Czech Republic, France, Germany, Hungary, Italy and Switzerland (Paukov et al. 2016; Nimis et al. 2018; Nimis & Martellos 2022). It occurs on basic and ultramafic rocks, including basalt, serpentinite, syenite and porphyry (Paukov et al. 2016). In Poland, the species has been reported from the Sudety Mts in the vicinity of the town of Jelenia Góra (Nowak & Tobolewski 1975) and in the Karpaty Mts in the Orawsko-Podhalańskie Depression (Bielczyk 2003).

All of the new A. goettweigensis localities presented in this paper are located in the area of low mountains in Lower Silesia (south-western Poland). An additional record was found after revision of the Stein’s specimen stored in the WRSL herbarium, which was originally identified as Aspicilia gibbosa (Ach.) Körb. All of the recorded specimens were found growing on silicate rocks in exposed locations, influenced by high insolation and rather low moisture at altitudes of up to 500 m.

Notes: Aspicilia goettweigensis can be confused with other members of the genus, especially A. laevata (Ach.) Arnold and A. verrucigera Hue, due to the very similar sizes of the ascospores and conidia, and the secondary chemistry. The most important distinguishing feature of A. goettweigensis, however, is the appearance of the thallus, which consists of characteristic overlapping and convex squamules. In the literature, these squamules are described as hollow, cracking into “popcorn-like tufts”, and showing white medulla in well-developed specimens (Paukov et al. 2016). In addition, unlike A. goettweigensis, A. laevata prefers shady and moist habitats, close to water or located in forests (Wirth 1995, Fletcher et al. 2009).

The nucITS marker was sequenced from four specimens (Table 1), and the BLAST analyses showed 98% to 100% identity with the sequences of A. goettweigensis deposited in GenBank (Table 2, data for A. goettweigensis). Sequences of the best hits originated from Russia and the Czech Republic (KX159292 and KX159293, respectively).

Material examined: POLAND. Dolnośląskie province: Sudety Mts, Jeleniogórska Basin, Łomnickie Hills, Witosza Hill near Staniszów village, elev. 484 m, on granite rock, March 1882, B. Stein (WRSL-5791); Sudety Mts, Opawskie Mts, Karolinki rocks near Jarnołtówek village, elev. 400 m, on natural outcrop of siliceous rocks in an oak grove, 18 February 2020, K. Szczepańska 1318, 1320 (Hb. Szczepańska); Sudeckie Foothills, Strzegomskie Hills, Krzyżowa Hill, elev. 360 m, on basalt rock, 19 May 2013, K. Szczepańska 1092, 1093 (Hb. Szczepańska); Sudeckie Foothills, Kaczawskie Foothills, Organy Wielisławskie quarry in Sędziszowa village, elev. c. 300 m, on porphyry rocks, 8 May 2020, K. Szczepańska 1333 (Hb. Szczepańska).