Bacidia heterochroa ( Muell . Arg.) Zahlbr., Cat. Lich. Univers. 4: 204 (1926) [1927]

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 heterochroa ( Muell. Arg.) Zahlbr., Cat. Lich. Univers. 4: 204 (1926) [1927]

Fig. 4

Description.

Thallus corticolous, crustose, continuous, wrinkled, or warted, pale yellowish-grey, margin indeterminate or determinate. Prothallus generally not present or locally present as blackish bordering a different lichen.

Apothecia flat, marginate, without pruina, 0.2-0.6 mm diam. (mean = 0.33, SD = 0.11, n = 72). Disc lecideine, without thalline exciple, blackish or reddish-black. Proper exciple hyaline with pale brown pigment dispersed, pigment slightly thicker close to hymenium, 80-100 μm wide laterally. Epihymenium brown to dark brown, ca. 10 μm high. Hymenium hyaline, 80-95 μm high. Hypothecium hyaline, 80-120 μm high, with a little pale yellow pigment. Crystals or oil droplets absent. Asci narrowly clavate to cylindrical, 8-spored, 42-48 × 12-13 μm (n = 3). Ascospores acicular to filiform, 9- or 10-septate, 36-67 × 2.5-4 μm (n = 11). Pycnidia not detected.

Chemistry.

Epihymenium K+ purple or intensifying, extending to excipular rim. No lichen substance was detected by TLC.

Notes.

Bacidia heterochroa is the most similar to B. laurocerasi (Delise ex Duby) Zahlbr. in having smooth thallus without granules, absence of crystals in exciple, epihymenium without green pigments, pale to colourless hypothecium, K+ purple in apothecial section and narrow ascospores less than 4 μm wide amongst corticolous species. However, B. heterochroa differs from B. laurocerasi by distinctly brown-pigmented paraphysial tips, less than 16-septate ascospores which are shorter but wider (less than 80 μm long but over 3.5 μm wide) and substrate preference to deciduous trees or shrubs ( Ekman 1996; Brodo 2016; also see the key couplet 21).

Phylogenetic analysis resulted in B. heterochroa of Korea (ON352606, ON352612 and ON352613) being nested in a sister clade to B. laurocerasi , supported by a bootstrap value of 75 without a posterior probability as the Maximum Likelihood analysis did not match with the Bayesian Inference for the clade. The sequences of B. heterochroa were not compared with previous records due to the lack of data (Fig. 2 ). Bacidia heterochroa was previously reported from Thailand in Asia ( Aptroot et al. 2007) and this is a new record to northeastern Asia.

Specimens examined.

South Korea, Gangwon Province, Yanggu, Nam-myeon, Dumu-ri , a forested wetland, 38°02.12'N, 128°05.14'E, 421 m alt., on bark of Salix koriyanagi Kimura ex Goerz, 28 April 2020, B.G. Lee 2020-000186 (KBA-L-0000386; GenBank ON352606 for ITS) ; South Korea, South Jeolla Province, Damyang, Changpyeong-myeon, Oedong-ri , a forested wetland, 35°12.00'N, 127°00.88'E, 338 m alt., on bark of Fraxinus rhynchophylla Hance, 12 May 2021, B.G. Lee & D.Y. Kim 2021-000214 (KBA-L-0001686) ; South Korea, Gangwon Province, Jeongseon, Imgye-myeon, Gamok-ri , a forested wetland, 37°32.47'N, 128°57.72'E, 760 m alt., on bark of Acer tartaricum subsp. ginnala (Maxim.) Wesm., 17 June 2021, B.G. Lee & H.J. Lee 2021-001241, with Lecanora chionocarpa Hue (KBA-L-0002713); same locality, on bark of Acer tartaricum subsp. ginnala , 17 June 2021, B.G. Lee & H.J. Lee 2021-001242, with Phaeophyscia adiastola (KBA-L-0002714); same locality, on bark of Acer tartaricum subsp. ginnala , 17 June 2021, B.G. Lee & H.J. Lee 2021-001255, with Opeltia flavorubescens , Phaeophyscia adiastola (KBA-L-0002727; GenBank ON352612 for ITS); same locality, on bark of Acer tartaricum subsp. ginnala , 17 June 2021, B.G. Lee & H.J. Lee 2021-001257, with Hyperphyscia adglutinata , Lecidella euphorea (KBA-L-0002729); same locality, on bark of Acer tartaricum subsp. ginnala , 17 June 2021, B.G. Lee & H.J. Lee 2021-001262, with Lecidella euphorea , Phaeophyscia adiastola , Rinodina orientalis (KBA-L-0002734; GenBank ON352613 for ITS); same locality, on bark of Acer tartaricum subsp. ginnala , 17 June 2021, B.G. Lee & H.J. Lee 2021-001263, with Opeltia flavorubescens , Phaeophyscia adiastola , Rinodina orientalis (KBA-L-0002735); same locality, on bark of Acer tartaricum subsp. ginnala , 17 June 2021, B.G. Lee & H.J. Lee 2021-001267, with Lecidella euphorea , Porina hirsuta , Rinodina orientalis , Straminella varia (KBA-L-0002739); same locality, on bark of Acer tartaricum subsp. ginnala , 17 June 2021, B.G. Lee & H.J. Lee 2021-001269, with Lecidella euphorea , Opeltia flavorubescens , Phaeophyscia rubropulchra , Rinodina orientalis (KBA-L-0002741) .

Figures

Figure 2. Phylogenetic relationships amongst available species in the genus Bacidia, based on a Maximum Likelihood analysis of the dataset of ITS sequences. The tree was rooted with the sequences of the genus Biatora, based on Gerasimova et al. (2018). Maximum Likelihood bootstrap values ≥ 70 % and posterior probabilities ≥ 95 % are shown above internal branches. Branches with bootstrap values ≥ 90 % are shown as thick lines. New sequences produced in this study are presented in bold. All species names are followed by the GenBank accession numbers.

Figure 4. Four new records of B. ekmaniana (KBA-L- 0000412 for A-C), B. friesiana (KBA-L- 0001914 for D-F), B. heterochroa (KBA-L- 0000386 for G-I) and B. suffusa (KBA-L- 0000359 for J-L) in morphology A habitus and apothecia. Granular thallus with green-grey pigment and straw-coloured apothecia B-C apothecial section with colourless epihymenium, red-brown hypothecium, and pale excipulum D habitus and apothecia. Thallus pale grey with slightly brownish pigment and pale pink apothecia E, F apothecial section with greenish epihymenium G habitus and apothecia. Thallus pale yellowish-grey and black apothecia with red pigment H, I apothecial section and proper exciple with dark margin J habitus and apothecia. Thallus whitish pale grey and pruinose apothecia K, L apothecial section with radiating clusters of crystals, which produce pruina on surface. Scale bars: 500 μm (A, D, G, J); 100 μm (B, E, H, K); 50 μm (C, I, L); 20 μm (F).