Squamarina oleosa (Zahlbr.) Poelt

Zhang, Yan-Yun, Wang, Xin-Yu, Li, Li-Juan, Printzen, Christian, Timdal, Einar, Niu, Dong-Ling, Yin, An-Cheng, Wang, Shi-Qiong & Wang, Li-Song, 2020, Squamarina (lichenised fungi) species described from China belong to at least three unrelated genera, MycoKeys 66, pp. 135-157 : 135

Squamarina oleosa (Zahlbr.) Poelt Fig. 5H, I

Lecanora oleosa Zahlbr., in Handel-Mazzetti, Symb. Sinic. 3: 175 (1930) (Basionym) Type: China, Yunnan Province, Lijiang Co., Mt. Yulongxueshan, on rock, 1914, Heinrich Frh. von Handel-Mazetti 3576 (W-holotype!)

Description.

Thallus placodioid to subfoliose, rather closely attached to calcareous rocks, olive-green turning to yellowish-brown in the herbarium, up to 8 cm across and 5 mm high in the centre; lobes 2-4 mm long, 1.5-2.5 mm wide, ca. 1 mm thick, apices usually detached from the substrate with a white thickened edge; upper surface pruinose at least on the margins, matt to somewhat shiny, centrally cracked and faveolate-wrinkled, strongly convex, giving the thallus centre a bullate appearance, the base of the bullae carbonised, black; lower surface covered with pale brown to blackish-brown pulvinate hyphae, with sparse to numerous rhizinose strands; rhizinose strands brown to black, irregularly branched, up to 5 mm long. Upper cortex filled with yellowish-brown granules, turning colourless in KOH, 62-75 μm high, without epinecral; algal layer continuous, 65-70 μm thick; medulla filled with grey crystals of calcium oxalate and brick-red hyphae in lower part; lower cortex lacking.

Apothecia common but not abundant, laminal, scattered to slightly grouped, up to 4 mm in diam.; disc concave, plane to convex, light yellow, covered by yellowish pruina; thalline margin pruinose or not, darker than thallus, shiny, entire and distinctive when young, excluded with age. Hymenium 75-85 μm high, hyaline, I+ blue; epihymenium filled with yellowish-brown granules, not disperse into hymenium, turning colourless in KOH, 5-12.5 μm high; thalline margin without algae in the upper part, cortex filled with yellowish-brown granules, 112-125 μm thick; paraphyses septate, tips not swollen; hypothecium colourless, 100-162 μm thick, with pale brown granules forming a narrow line; algal layer below hypothecium continuous, 50-75 μm thick; ascus Porpidia -type, 8-spored. Ascospores ellipsoid to subfusiform, 15-20 × 5-7 μm. Pycnidia rare and small, ostioles yellow to yellowish-brown, conidia colourless, filiform, curved, 15-22.5 × ca. 0.7 μm.

Chemistry.

Upper cortex K-, C-, P-, medulla K-, C-, P+ yellow; usnic, psoromic and 2'-O-demethylpsoromic acids.

Ecology and distribution.

Growing on rock at elevations of 2623-3440 m. Only known from Yunnan Prov., China.

Notes.

The holotype grows on calcareous rock and bears only one apothecium.

This species was originally described as a Lecanora by Zahlbruckner (1930) and transferred to Squamarina by Poelt (1958). It is characterised by the thick, olive-green, placodioid to subfoliose thallus, yellowish apothecia covered with yellow pruina, the ellipsoid to subfusiform ascospores and the filiform, curved conidia. This species is the most basal clade in our reconstruction of the genus and it is close to S. cartilaginea and S. gypsacea (Fig. 6 ); however, S. cartilaginea differs in the non-pruinose, yellowish- to reddish-brown apothecia, smaller ascospores 10-14 × 4-6 μm and S. gypsacea differs in the yellowish-green, squamulose thallus, the very large and thick squamules that adnate to the substratum only by the central part and the larger apothecia (up to 1 cm). Squamarina kansuensis and S. lentigera can be distinguished from this species by the strongly white pruinose thallus, thinner lobes (<0.5 mm) and smaller (<2 mm) apothecia with non-pruinose and reddish-brown disc.

Specimens examined (all in KUN-L unless otherwise noted).

China: Yunnan Province: Lijiang Co., 3440 m elev., on rock, 2009, Li-Song Wang & Wang Jue 09-30034, Yulong Snow Mt., 26°56'N, 100°12'E, 2623 m elev., on calcareous rock, 2019, Li-Song Wang & Yan-yun Zhang 19-66398, 19-66399, 19-66401, 19-66402, 19-66404.

Squamarina gypsacea (O).

Greece: Corfu, hill above Troumpetas, 420 m elev., 39°74'N, 19°86'E, on exposed limestone outcrops, 2014, Rui, S. & Timdal, E., O-L-196249, Sokrati - Zigos road, 370 m elev., 39°72'N, 19°80'E, on rather shady limestone boulders in olive groove, 2014, Rui, S. & Timdal, E., O-L-196255; Kavalla, Thassos, along dirt road from Maries to Theologos, near Vatos, 590 m elev., 40°70'N, 24°66'E, on E-facing limestone wall in/above steep pine forest, 2000, Rui, S. & Timdal, E., O-L-59266. Spain: Alicante, between Callosa de Ensarria and Confrides, 260 m elev., 38°68'N, - 0°21'E, 1985, Timdal, E., O-L-16444.

Figures

Figure 5. Lecanora chondroderma (A, B KUN-L 18 - 60317): A habit B apothecial anatomy (LCB) and ascospores (water). Squamarina kansuensis (C-G KUN-L 18 - 59601): C habit D apothecial anatomy (LCB) E ascus and ascospores (LCB) F apical structure of ascus (Lugol's) G section of thallus (LCB). S. oleosa (H, I KUN-L 09 - 30043): H habit I ascus and ascospores (water). Scale bars: 100 μm (B - apothecia, D); 5 μm (B - ascospores, F); 10 μm (E); 20 μm (G); 25 μm (I).

Figure 6. Maximum Likelihood phylogeny of the genus Squamarina and related genera, based on nrLSU. ML bootstrap value ≥ 70 % and posterior probabilities ≥ 0.95 from the Bayesian analysis are given adjacent to nodes.