Pyrenodesmia rugosa B.G. Lee & J.-S. Hur, 2021

Lee, Beeyoung Gun & Hur, Jae-Seoun, 2021, Two new calcicolous caloplacoid lichens from South Korea, with a taxonomic key to the species of Huriella and Squamulea, MycoKeys 84, pp. 35-55 : 35

Pyrenodesmia rugosa B.G. Lee & J.-S. Hur sp. nov.

Fig. 6

Diagnosis.

Pyrenodesmia rugosa differs from P. micromontana by thicker thallus (125-200 μm vs. 95-125 μm), rugose areoles (vs. flat areoles), larger apothecia (0.2-0.7 mm diam. vs. 0.2-0.4 mm diam.), shorter hymenium (60-70 μm vs. 80-100 μm), shorter hypothecium (50-55 μm vs. 80-100 μm) and narrower tip cells of paraphyses (3-4.5 μm vs. 5-6 μm).

Type.

South Korea, Gangwon Province, Gangneung, Okgye-myeon, Mt. Seokbyung (summit), 37°35.21'N, 128°53.87'E, 1,072 m alt., on calcareous rock, 17 June 2020, B.G.Lee & H.J.Lee 2020-000902, with Athallia cf. vitellinula (Nyl.) Arup, Frödén & Søchting, Bagliettoa baldensis (A. Massal.) Vězda, Catillaria lenticularis (Ach.) Th. Fr. and Staurothele aff. succedens (Rehm) Arnold (holotype: BDNA-L-0001102!); same locality, on calcareous rock, 17 June 2020, B.G.Lee & H.J.Lee 2020-000899, with Athallia cf. holocarpa (Hoffm.) Arup, Frödén & Søchting and Staurothele cf. rupifraga (A. Massal.) Arnold (paratype: BDNA-L-0001099; GenBank MW832828 for ITS, MW832825 for mtSSU and MW832804 for LSU) .

Thallus saxicolous (calcicolous), crustose, mainly areolate or slightly rimose, rugose, greyish-brown to pale brown, often with orange spots, margin indeterminate or determinate when placodioid areoles are arranged around edge, vegetative propagules absent, areoles 0.4-1.0 mm diam., 125-200 μm thick; cortex hyaline with pale brown pigment layer, pale brown pigment K+ purple, 10-40 μm thick, cortical cells granular, 5-10 μm diam., with epinecral layer, 5-7 μm thick; medulla 60-110 μm thick below algal layer or inconspicuous and algal layer shown just above substrate; photobiont coccoid, cells globose to oval, 5-15 μm diam., algal layer 50-70 μm thick. Small crystals present between algal cells, not dissolving in K. Prothallus absent.

Apothecia abundant, scattered or concentrated in centre, rounded, often contiguous or even coalescent when mature, emerging on the surface of thallus, immersed or adnate, slightly constricted at the base, 0.2-0.7 mm diam. Disc flat when young and flat or concave when mature, often white pruinose, black, 200-300 μm thick; zeorine, margin persistent, slightly prominent, generally entire or rarely slightly crenulate, thalline margin paler to disc and showing brown colour, often inconspicuous due to locating below proper margin, proper margin concolorous to disc. Amphithecium present, with small crystals between algal cells, not dissolving in K, 80-130 μm wide laterally, algal layers continuous to the base and underlying the hypothecium, algal cells 5-15 μm diam., cortical layer hyaline with pale brownish pigment at periphery, 10-40 μm thick. Parathecium well-developed, hyaline, but grey with slightly brown pigment concolorous to epihymenium at periphery, 20-40 μm wide laterally and 50-90 μm wide at periphery. Epihymenium grey with slightly brown pigment, K+ purple, tiny granules abundant on surface, not dissolving in K, 5-10 μm high. Hymenium hyaline, 60-70 μm high. Hypothecium hyaline, base open and extending downwards, 50-55 μm high. Oil droplets present in upper hypothecium, but absent in hymenium. Paraphyses septate, often anastomosing, 2-2.5 μm wide, generally simple, but occasionally branched at tips, tips slightly swollen, not pigmented, 3.0-4.5 μm wide. Asci oblong to narrowly clavate, 8-spored, 52-60 × 14-18 μm (n = 5). Ascospores ellipsoid, 1-septate, polarilocular when mature or narrow septum remaining, hyaline permanently, 11-18 × 5.5-11 μm (mean = 14.1 × 7.6 μm; SD = 1.6(L), 1.0(W); L/W ratio 1.5-2.5, ratio mean = 1.9, ratio SD = 0.3; n = 105), septum 1.5-3.0 μm. Pycnidia not detected.

Chemistry.

Thallus K-, KC-, C-, Pd-. Epihymenium K+ purple. Hymenium I+ blue. UV-. No lichen substance was detected by TLC.

Distribution and ecology.

The species occurs on the calcareous rock. The species is currently known from the type collections.

Etymology.

The species epithet indicates the lichen’s thallus texture, rugose or wrinkled, which is the key characteristic distinguished from closely-related calcicolous species in the genus Pyrenodesmia .

Notes.

The new speices is similar to P. micromontana , P. microstepposa and Caloplaca micromarina Frolov, Khodos. & Vondrák in having epilithic thallus without vegetative propagules, small apothecia generally less than 0.5 mm diameter and the substrate preference to calcareous rocks. The new species differs from P. micromontana by thicker thallus (125-200 μm vs. 95-125 μm), rugose areoles (vs. flat areoles), larger apothecia (0.2-0.7 mm diam. vs. 0.2-0.4 mm diam.), shorter hymenium (60-70 μm vs. 80-100 μm), shorter hypothecium (50-55 μm vs. 80-100 μm) and narrower tip cells of paraphyses (3-4.5 μm vs. 5-6 μm) ( Frolov et al. 2016).

The new species is different from P. microstepposa by darker thallus (greyish-brown to pale brown vs. ochre, grey or grey-white), rugose thallus (vs. flat thallus), thinner thallus (125-200 μm vs. 85-370 μm), smaller algal cells (5-15 μm diam. vs. 13.5-20.5 μm diam.), presence of pruina on disc (vs. absence of it), absence of oil droplets in hymenium (vs. presence of it), greyish epihymenium (vs. brownish epihymenium), wider ascospores (11-18 × 5.5-11 μm with the L/W ratio of 1.5-2.5 vs. 13.6-18.4 × 6-7.9 μm with the ratio of 1.9-2.9) ( Frolov et al. 2016).

The new species is distinguished from C. micromarina by darker thallus (greyish-brown to pale brown vs. ochre to grey), rugose thallus (vs. flat thallus), absence of pruina on thallus (vs. presence of it), shorter hymenium (60-70 μm vs. 90-100 μm), shorter septum (1.5-3 μm vs. 2.6-3.4 μm) and the habitat preference to mountain rocks (vs. coastal rocks) ( Frolov et al. 2016).

Additional specimens examined: South Korea, Gangwon Province, Okgye-myeon, Mt. Seokbyung (summit), 37°35.21'N, 128°53.87'E, 1,072 m alt., on calcareous rock, 17 June 2020, B.G.Lee & H.J.Lee 2020-000889, with Bagliettoa baldensis , Catillaria lenticularis , Fulgogasparrea decipioides (Arup) S.Y. Kondr., M.H. Jeong, Kärnefelt, Elix, A. Thell & Hur and Laundonia flavovirescens (Wulfen) S.Y. Kondr., Lőkös & Hur (BDNA-L-0001089); same locality, on calcareous rock, 17 June 2020, B.G.Lee & H.J.Lee 2020-000909, with Bagliettoa baldensis , Rusavskia elegans (Link) S.Y. Kondr. & Kärnefelt and Verrucaria nigrescens Pers. (BDNA-L-0001109); same locality, on calcareous rock, 17 June 2020, B.G.Lee & H.J.Lee 2020-000910, with Bagliettoa baldensis , Catillaria lenticularis and Laundonia flavovirescens (BDNA-L-0001110); same locality, on calcareous rock, 17 June 2020, B.G.Lee & H.J.Lee 2020-000911, with Athallia cf. vitellinula , Bagliettoa baldensis , Lichenella sp. and Rusavskia elegans (BDNA-L-0001111); same locality, on calcareous rock, 17 June 2020, B.G.Lee & H.J.Lee 2020-000913, with Athallia cf. vitellinula , Bagliettoa baldensis , Endocarpon sp., Laundonia flavovirescens , Lichenella sp. and Rusavskia elegans (BDNA-L-0001113); same locality, on calcareous rock, 17 June 2020, B.G.Lee & H.J.Lee 2020-000916, with Caloplaca sp., Endocarpon sp., Lichenella sp. and Rusavskia elegans (BDNA-L-0001116).

Figures

Figure 6. Pyrenodesmia rugosa (BDNA-L- 0001102, holotype) in morphology A-C habitus and apothecia. Rugose thallus brown with orange spots and without pruina, but black apothecia often white pruinose D-E zeorine apothecia with well-developed parathecium. Algal layers continue to the base and underlying the hypothecium F epihymenium K + purple and tiny granules not dissolving in K G-K asci oblong to narrowly clavate with eight spores K in the lactophenol cotton blue L ascospores simple in the beginning and developed polarilocular at maturity M paraphyses anastomosing in lactophenol cotton blue. Paraphysis tips slightly swollen. Scale bars: 1 mm (A-C); 100 μm (D); 50 μm (E, F); 10 μm (G-M).