Rinodina salicis B.G. Lee & J.-S. Hur, 2022

Lee, Beeyoung Gun & Hur, Jae-Seoun, 2022, Two new Rinodina lichens from South Korea, with an updated key to the species of Rinodina in the far eastern Asia, MycoKeys 87, pp. 159-182 : 159

Rinodina salicis B.G. Lee & J.-S. Hur sp. nov.

Fig. 4

Diagnosis.

Rinodina salicis differs from R. excrescens by olive-gray thallus with smaller areoles without blastidia, contiguous apothecia, the absence of pruina on disc, paler disc color, wider ascospores in the Pachysporaria -type, and the absence of secondary metabolites.

Type.

South Korea, Gangwon Province, Gangneung, Seongsan-myeon, Eoheul-ri , a forested wetland, 37°43.61'N, 128°48.13'E, 212 m alt., on bark of Salix koreensis Andersson, 02 June 2020, B.G.Lee & H.J.Lee 2020-000358 (holotype: BDNA-L-0000558; GenBank MW832810 for ITS); same locality, on bark of Salix koreensis , 02 June 2020, B.G.Lee & H.J.Lee 2020-000360, with Caloplaca gordejevii (Tomin) Oxner, Lecanora sp., and Phaeophyscia sp. (paratype: BDNA-L-0000560; GenBank MW832811 for ITS) .

Thallus corticolous, crustose, minutely bullate, some developing to conglomerate and continuous, rarely lobulated, thin, grayish-green to olive green, margin indeterminate, vegetative propagules absent, areoles 0.1-0.2 mm diam., 85-90 μm thick; cortex hyaline, 10 μm thick, cortical cells 5-9 μm diam.; medulla 60-65 μm thick, intermixed with algal cells, without crystals (PL-); photobiont coccoid, cells globose, 5-15 μm. Prothallus absent.

Apothecia abundant, rounded, often contiguous, emerging on the surface of thallus and sessile when mature, constricted at the base, 0.2-1.3 mm diam. Disc flat, not pruinose, pale brown or dark brown from early stages, 220-260 μm thick; margin persistent, prominent, generally entire or somewhat flexuous, a little crenulate, thalline margin concolorous to thallus but proper margin near disc distinctly pale brown. Amphithecium well-developed, with small crystals in both cortical layer and the algal-containing medulla, crystals extending to the base, not dissolving in K, 60-70 μm wide laterally, algal layers continuous to the base or solitary, algal cells 5-15 μm diam., cortical layer hyaline, 10-20 μm thick. Parathecium hyaline but light brown at periphery, 45-50 μm wide laterally and 70-80 μm wide at periphery. Epihymenium brown, not granular, pigment slightly paler in K but not diluted, 5-10 μm high. Hymenium hyaline, 70-90 μm high. Hypothecium generally hyaline, with pale yellow pigment, prosoplectenchymatous (irregular), 70-80 μm high. Oil droplets are present mainly in hypothecium and a little in hymenium. Paraphyses septate, anastomosing, 1-1.5 μm wide, simple or branched at tips, tips swollen, pigmented, epihymenium pigmented by paraphysial tips, 4.5-7.5 μm wide. Asci clavate, 8-spored, 68-90 × 20-25 μm (n = 5). Ascospores ellipsoid, 1-septate, Pachysporaria - type II, rarely Physcia - type, Type A development, hyaline when young and light brown to brown in mature, 14-24 × 8-13.5 μm (mean = 18.2 × 10.5 μm; SD = 2.12(L), 1.19(W); L/W ratio 1.2-2.4, ratio mean = 1.7, ratio SD = 0.2; n = 105). Pycnidia not detected.

Chemistry.

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

Distribution and ecology.

The species occurs on the bark of Salix koreensis . The species is currently known from the type collections.

Etymology.

The species epithet indicates the lichen’s substrate preference, namely the substrate tree Salix koreensis .

Notes.

The new species is similar to R. excrescens and R. bullata Sheard & Lendemer in having bullate thallus. However, the new species differs from R. excrescens by olive-gray thallus with smaller areoles without having blastidia, contiguous apothecia, the absence of pruina on disc, paler disc color, ascospore type, larger ascospore, and the absence of secondary metabolites ( Sheard 1966; Sheard et al. 2012).

The new species is closer to R. bullata in having small bullate areoles without having blastidia. However, the new species differs from the latter by olive-gray thallus, contiguous and larger apothecia, proper margin with pale brown color, crystals present in both cortex and medulla in amphithecium, larger ascospores, K- reaction on thallus, and the absence of lichen substance (Sheard et al. 2012, 2017).

The new species is comparable to R. granulans Vain. as the latter represents thallus with minute areoles. However, the new species differs from the latter by thallus color, slightly smaller areoles without blastidia, abundance of apothecia without pruina, Pachysporaria -type II ascospores, K- reaction on thallus, and the absence of lichen substance ( Giralt et al. 1994; Galanina et al. 2011). Reference Table 2 provides the key characteristics distinguishing R. salicis from the compared species above.

Figures

Figure 4. Rinodina salicis (BDNA-L- 0000558, holotype) in morphology A-D habitus and apothecia. Thallus olive-gray composed of tiny areoles and non-pruinose apothecia E well-developed amphithecium and algal layer extending to the base F asci clavate with eight spores G ascospores simple in the beginning and developed 1 - septate, Pachysporaria - type II, rarely Physcia - type at mature. Scale bars: 1 mm (A-D); 200 μm (E); 10 μm (F, G).