Bacidia fuscopallida B.G. Lee & T.I. Heo, 2022

Lee, Beeyoung Gun & Hur, Jae-Seoun, 2022, A new species and four new records of Bacidia (Lecanorales, Ramalinaceae) from South Korea, with a key to Korean species, MycoKeys 93, pp. 107-130 : 107

Bacidia fuscopallida B.G. Lee & T.I. Heo sp. nov.

Fig. 3

Diagnosis.

Bacidia fuscopallida differs from B. diffracta by generally non-granular, olive-green thallus, pale yellow-orange apothecia without pruina, the absence of crystals in proper exciple, slightly narrower ascospores with up to 15-septation and smaller pycnidia and pycnoconidia.

Type.

South Korea, Gangwon Province, Gangneung, Okgye-myeon, Mt. Seokbyung , 37°34.45'N, 128°55.00'E, 271 m alt., on bark of Acer pictum var. mono (Maxim.) Maxim. ex Franch., 17 June 2020, B.G. Lee & H.J. Lee 2020-000811, with Porina hirsuta Aptroot & K.H. Moon (holotype: KBA-L-0001011!); same locality, on bark of Acer pictum var. mono , 17 June 2020, B.G. Lee & H.J. Lee 2020-000801 (isotype: KBA-L-0001001); same locality, on bark of Acer pictum var. mono , 17 June 2020, B.G. Lee & H.J. Lee 2020-000806, with Mikhtomia gordejevii (Tomin) S.Y. Kondr., Kärnefelt, Elix, A. Thell, Jung Kim, A.S. Kondr. & Hur, Straminella varia (Hoffm.) S.Y. Kondr., Lőkös & Farkas, Phaeophyscia limbata (Poelt) Kashiw., Porina hirsuta (isotype: KBA-L-0001006); same locality, on bark of Acer pictum var. mono , 17 June 2020, B.G. Lee & H.J. Lee 2020-000810 (isotype: KBA-L-0001010; GenBank ON352607 for ITS) ; South Korea, Gangwon Province, Gangneung, Okgye-myeon, Mt. Seokbyung , 37°34.39' N, 128°55.01'E, 349 m alt., on bark of Quercus mongolica Fisch. ex Ledeb., 17 June 2020, B.G. Lee & H.J. Lee 2020-000837, with Opeltia flavorubescens (Huds.) S.Y. Kondr. & Hur (paratype: KBA-L-0001037) ; South Korea, Gangwon Province, Gangneung, Okgye-myeon, Mt. Seokbyung , 37°34.28'N, 128°54.88'E, 438 m alt., on bark of Acer triflorum Kom., 17 June 2020, B.G. Lee & H.J. Lee 2020-000849, with Biatora pacifica Printzen, Tønsberg & G. Thor (paratype: KBA-L-0001049; GenBank ON352608 for ITS) .

Thallus corticolous, crustose, areoles in young stage and soon coarsely continuous or warted on aging, often overlapping for each other, rarely granular, thin when not overlapping, olivish-green, margin indeterminate, 40-90 μm thick; cortex indistinct, hyaline, up to 5 μm thick; medulla a little shown as mycelia below algal layer; photobiont chlorococcoid, cells globose to subglobose, 5-15 μm thick, algal layer composing most part of thallus, 35-80 μm thick. Prothallus indistinct or whitish-grey and endosubstratal when present.

Apothecia numerous, solitary, marginate and flat in young stage and seeming immarginate and convex on aging (consistently marginate and flat on bark of Acer triflorum ), 0.1-0.7 mm diam. (mean = 0.33; SD = 0.14; n = 105). Pruina absent. Disc biatorine, thalline exciple absent, pale yellow to pale orange in young stage and slightly more blackish generally around margin when mature (much more blackish on bark of A. triflorum and Q. mongolica from young stage). Proper exciple 65-80 μm wide laterally (SD = 5.7; n = 15), with radiating hyphae of 1-2.5 μm wide (SD = 0.5; n = 10) and outermost cell 2.5-4 μm wide (SD = 0.6; n = 10), hyaline to pale yellow around rim, but darker downwards (pale yellow to pale brown) and the dark colour extending to hypothecium. Epihymenium hyaline, with a little pigment of pale yellow to pale olive-brown locally, smooth and not granular, ca. 5 μm high. Hymenium hyaline, 70-100 μm high (SD = 8.9; n = 10). Hypothecium clearly pigmented, pale orange-brown to brown, prosoplectenchymatous (irregularly arranged), 70-130 μm high (SD = 18.9; n = 10). Crystals absent or a little present in upper hypothecium. Oil droplets absent. Paraphyses simple, rarely branched at tips, 1-1.5 μm wide, tips not or little swollen, not pigmented, 1.5-2 μm wide. Asci cylindrical to narrowly clavate, 8-spored, 49-72 × 11-14 μm (SD = 7.3 (L), 0.9 (W); n = 11). Ascospores 3- to 15-septate, acicular to filiform, 24-69 × 2-3.5 μm (mean = 52.8 × 2.6 μm; SD = 8.7 (L), 0.6 (W); L/W ratio = 3.8-30.5, ratio mean = 17.6, ratio SD = 5.0; n = 104). Pycnidia black, immersed and upper half only shown, globose, 60-65 μm high and 55-75 μm wide (SD = 2.4 (H), 8.2 (W); n = 5), with brownish wall, K-. Pycnoconidia hyaline, filiform, curved or almost straight, 6-17 × 0.3-0.5 μm (mean = 10.4 × 0.5 μm; SD = 2.9 (L), 0.1 (W); n = 53).

Chemistry.

Thallus K- or K+ slightly yellow, KC-, C-, Pd-, UV-. Epihymenium K+ purple extending to outermost layers of proper exciple, C-. No lichen substance was detected by TLC.

Distribution and ecology.

The species occurs on barks of Acer pictum var. mono , A. triflorum and Quercus mongolica . The species is currently known from the type collections.

Etymology.

The species epithet indicates the pale brown colour of the lichen’s apothecia.

Notes.

The new species is similar to B. diffracta and B. polychroa (Th. Fr.) Körb. in having colourless epihymenium with pale orange-brown pigment and K+ purple reaction, distinctly pigmented hypothecium with yellow, orange or brown, long ascospores generally with L/W ratio over 10 amongst corticolous species. However, B. diffracta differs from the new species by granular thallus, darker and larger apothecia with pruina, proper exciple with radiating clusters of minute crystals, slightly wider ascospores with up to 11-septation and larger pycnidia and pynoconidia ( Ekman 1996) (Table 3 ).

The new species is more similar to B. polychroa in having coarsely continuous or warted thallus. However, B. polychroa differs from the new species by greyish thallus, darker and larger apothecia often with pruina, proper exciple often with radiating clusters of minute crystals, wider ascospores and larger pycnidia and pycnoconidia ( Ekman 1996; Smith et al. 2009) (Table 3 ).

The new species is quite similar to B. purpurans R. C. Harris, Ladd & Lendemer in having greenish thallus with areoles and K+ purple reaction in epihymenium. However, B. purpurans differs from the new species by arachnoid prothallus, darker apothecia, green excipular rim adjacent to epihymenium, greyish epihymenium, shorter hypothecium, absence of crystals, larger ascospores and larger pycnidia and pycnoconidia ( Lendemer et al. 2016) (Table 3 ).

The new species can be compared with B. hostheleoides in sharing non-pruinose apothecia and proper exciple without crystals. However, B. hostheleoides differs from the new species by greyish thallus, absence of prothallus, shorter hymenium, paler hypothecium and shorter ascospores with a few septa ( Ekman 1996) (Table 3 ).

Figures

Figure 3. Bacidia fuscopallida (KBA-L- 0001011, holotype for A-D, G-O KBA-L- 0001049 for E, F KBA-L- 0001010 for P, Q) in morphology A, B habitus and apothecia on bark of Acer pictum var. mono. Olive-green thallus and pale yellow-orange apothecia C vertical section of apothecia D prothallus present around margin of habitus (red arrows) E, F habitus and apothecia growing on bark of Acer triflorum G apothecial section H epihymenium colourless or a little pigmented I epihymenium K + purple J small crystals (red arrows) present in upper hypothecium K proper exciple pigmented with pale or colourless margin. Radiating hyphae wider to margin L photobiont composing most part of thallus M, N asci cylindrical to narrowly clavate. Ascospores not twisted in ascus O ascospores acicular to filiform up to 15 - septate P pycnidia globose with brown wall Q pycnoconidia curved or almost straight. Scale bars: 1 mm (A, E); 500 μm (B, C, F); 2 mm (D); 200 μm (G); 50 μm (H-J, P); 20 μm (K, L); 10 μm (M-O, Q).