Lecanora parasymmicta B.G. Lee & J.-S. Hur, 2021

Lee, Beeyoung Gun & Hur, Jae-Seoun, 2021, Two new lecanoroid lichen species from the forested wetlands of South Korea, with a key for Korean Protoparmeliopsis species, MycoKeys 84, pp. 163-183 : 163

Lecanora parasymmicta B.G. Lee & J.-S. Hur sp. nov.

Fig. 6

Diagnosis.

Lecanora parasymmicta differs from L. symmicta , the most similar species, by its areolate-rimose thallus (vs. areolate to leprose thallus), blackish hypothallus (vs. hypothallus indistinct), larger apothecia (up to 1.7 mm diam. vs. up to 1 mm diam.), absence of thalline excipulum from the beginning (vs. presence of thalline excipulum when young at least), narrower paraphyses (1-1.5 μm vs. 2-2.5 μm), larger ascospores (11-18 × 4-7 μm vs. 9-15.5 × 4-5 μm), smaller pycnoconidia (12-21 × 0.5-0.8 μm vs. 18-25 × 0.5-1.0 μm), chemical reactions (thallus K ± slightly yellow, C-, KC- and UV- vs. K-, C ± orange, KC ± slightly yellow, UV+ dull orange), and the presence of placodiolic acid (vs. presence of arthothelin and ± thiophanic acid).

Type.

South Korea, Jeju Island, Aewol-eup, Gwangnyeongri /bongseongri, Mt. Halla , a forested wetland, 33°21.85'N, 126°26.91'E, 980 m alt., on bark of Maackia fauriei (H. Lév.) Takeda , 08 July 2020, B.G.Lee & H.J.Lee 2020-001020, with Graphis scripta (L.) Ach. (holotype: BDNA-L-0001220; GenBank MW832794 for ITS and MW832800 for mtSSU) ; same locality, on bark of Malus sieboldii (Regel) Rehder , 08 July 2020, B.G.Lee & H.J.Lee 2020-001018, (paratype: BDNA-L-0001218; GenBank MW832793 for ITS and MW832799 for mtSSU) ; same locality, on bark of Malus sieboldii , 08 July 2020, B.G. Lee & H.J.Lee 2020-001019, with Phaeographis aff. inusta (paratype: BDNA-L-0001219) ; same locality, on bark of Maackia fauriei , 08 July 2020, B.G. Lee & H.J.Lee 2020-001026, (paratype: BDNA-L-0001226) ; same locality, on bark of Maackia fauriei , 08 July 2020, B.G. Lee & H.J. Lee 2020-001035, with Lecanora megalocheila (Hue) H. Miyaw. (paratype: BDNA-L-0001235; GenBank MW832795 for ITS and MW832801 for mtSSU) ; same locality, on bark of Ligustrum obtusifolium Siebold & Zucc., 08 July 2020, B.G. Lee & H.J. Lee 2020-001036, with Graphis scripta (paratype: BDNA-L-0001236) .

Description.

Thallus corticolous, crustose, areolate to rimose but not leprose, light olivish gray to light gray, margin determinate, not pruinose, 60-200 μm thick; cortex hyaline, 5-10 μm thick; medulla often intermixed with algae and even with bark layer, small crystals in cortex or between algae, dissolving in K; photobiont coccoid, cells globose to ellipsoid, 5-15 μm. Hypothallus blackish.

Apothecia abundant, rounded, often contiguous or even coalescent, emerging on the surface of thallus and sessile when mature but margin generally attached to thallus surface, constricted at the base, 0.3-1.7 mm diam. Disc flat in the beginning and soon convex, smooth or becoming rugose by apothecia adjoining, not pruinose or slightly pruinose, pale yellow in the beginning and slightly darker when mature, sometimes with dark spots (algae), 180-400 μm thick; biatorine. Thalline excipulum absent from the beginning, proper excipulum present and sometimes slightly paler than disc, more distinctive when young, hyaline but yellowish brown to pale brown at periphery with granules which dissolving in K, periphery color same to epihymenium, ca. 90 μm wide laterally and 70-80 μm wide at periphery, disappearing to the base. Epihymenium yellowish brown to pale brown, granular, dissolving in K, 10-20 μm high. Hymenium hyaline, 70-90μm high. Subhymenium hyaline, 30-50 μm high. Hypothecium hyaline, prosoplectenchymatous (irregular), 50-60 μm high. Crystals and oil droplets absent in apothecial section. Paraphyses septate, anastomosing, 1-1.5 μm wide, simple or branched at tips, tips not swollen or slightly swollen, not pigmented, epihymenium pigmented by granules, not by paraphysial tips, ca. 1.5 μm wide. Asci clavate, 8-spored, 50-60 × 13-21 μm (n = 7). Ascospores constantly simple but rarely 1-septate, coarsely biseriate or irregularly arranged, 11-18 × 4-7 μm (mean = 13.8 × 5.8 μm; SD = 1.62(L), 0.63(W); L/W ratio 1.8-4.0, ratio mean = 2.4, ratio SD = 0.3; n = 105). Pycnidia immersed, ostiolar region slightly projected with a thalline excipulum, round to irregularly asymmetric, brown to black, 220 × 180 μm. Pycnoconidia thread-like, generally curved, 12-21 × 0.5-0.8 μm.

Chemistry.

Thallus K- or K+ slightly yellowish, KC-, C-, Pd-. Hymenium, epihymenium and ascus tholus I+ blue. UV-. Usnic acid, zeorin, and placodiolic acid were detected by TLC.

Distribution and ecology.

The species occurs on the bark of Ligustrum obtusifolium , Maackia fauriei , and Malus sieboldii . The species is currently known from the type collections.

Etymology.

The species epithet indicates the lichen’s morphological similarity to the close species Lecanora symmicta .

Notes.

The new species is morphologically similar to Lecanora symmicta in its areolate and gray thallus, yellowish apothecia without developed thalline excipulum, yellowish brown epihymenium filled with pigmented granules which dissolving in K, and the presence of conidia. However, the new species differs from L. symmicta by its areolate-rimose thallus, blackish hypothallus, larger apothecia, absence of thalline excipulum from the beginning, narrower paraphyses, larger asci, larger ascospores, smaller pycnoconidia, chemical reaction, and the presence of placodiolic acid ( Brodo et al. 2001; Nash III et al. 2004; Smith et al. 2009).

The new species is comparable to Lecanora aitema (Ach.) Hepp, L. confusa , and L. strobilina in the L. symmicta group as all those are corticolous without soredia or leprose thallus. However, the new species differs from L. aitema by olive-gray to gray thallus, blackish hypothallus, larger and paler apothecia, absence of thalline excipulum from the beginning, larger asci, wider ascospores, chemical reaction, presence of placodiolic acid, and the substrate preference to deciduous trees/shrubs (vs. conifers) ( Smith et al. 2009).

The new species is different from Lecanora confusa by the absence of thalline excipulum from the beginning, larger asci, larger ascospores, chemical reaction, and the presence of placodiolic acid ( Nash III et al. 2004; Smith et al. 2009).

The new species is distinguished from Lecanora strobilina by olive-gray to gray thallus without pruina, presence of black hypothallus, absence of thalline excipulum from the beginning, yellow-brown epihymenium, absence of crystals in apothecial section, larger asci, larger ascospores, smaller pycnoconidia, chemical reaction, and the presence of placodiolic acid ( Brodo et al. 2001; Smith et al. 2009). Molecular phylogeny strongly supports that the new species is distinct in the L. symmicta group without any species close to it, illustrating the compared species above are located in different clades far from the new species (Figs 2 and 3 ). Reference Table 2 provides the key characteristics distinguishing L. parasymmicta from the closely related species in the L. symmicta group above.

All above compared species do not contain placodiolic acid and Lecanora species with placodiolic acid, such as L. placodiolica Lumbsch & Elix, L. cinereofusca H. Magn., L. sarcopidoides (A. Massal.) Hedl., L. subravida Nyl., L. semitensis (Tuck.) Zahlbr. and L. opiniconensis Brodo, are considered for discriminating the new species. Lecanora placodiolica differs from the new species by yellowish thallus, absence of hypothallus, presence of thalline excipulum, and darker (red-brown) discs ( Lumbsch and Elix 1998). Lecanora cinereofusca belongs to the L. subfusca group with large crystals, and L. sarcopidoides and L. subravida are the members of the L. saligna group with presence of thalline excipulum and smaller ascospores ( Van den Boom and Brand 2008). They are quite different from the new species in morphology although they produce placodiolic acid. Lecanora semitensis differs from the new species by yellowish thallus, darker (dark grayish brown to yellow) discs, presence of thalline excipulum, smaller ascospores (8-12 × 4-5 μm), and the substrate preference to rock other than bark of trees ( Nash III et al. 2004). Lecanora opiniconensis represents yellowish thallus composed of lobate areoles, absence of hypothallus, presence of thalline excipulum, absence of zeorin, and the substrate preference to siliceous rock other than bark of trees ( Brodo 1986).

Lecanora symmicta specimens examined.

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 Alnus sibirica Fisch. ex Turcz., 02 June 2020, B.G.Lee & H.J.Lee 2020-000347, with Lecanora strobilina , Lecidella euphorea ( Flörke) Kremp., Traponora varians (Ach.) J. Kalb & Kalb (BDNA-L-0000547; GenBank MW832788 for ITS); same locality, on bark of Alnus sibirica , 02 June 2020, B.G.Lee & H.J.Lee 2020-000348, two variants (one with pale brown discs and the other with yellow discs) of Lecanora symmicta with Lecidella euphorea , Rinodina sp., Traponora varians (BDNA-L-0000548; GenBank MW832789 for ITS of the former variant and GenBank MW832790 for ITS of the latter); same locality, on bark of Alnus sibirica , 02 June 2020, B.G.Lee & H.J.Lee 2020-000351, two above variants of Lecanora symmicta with Traponora varians (BDNA-L-0000551; GenBank MW832791 for ITS); Pyeongchang-gun, Daegwallyeong-myeon, Hoenggye-ri, a forested wetland, 37°46.00'N, 128°42.33'E, 1,047 m alt., on bark of Maackia amurensis Rupr. & Maxim., 03 June 2020, B.G.Lee & H.J.Lee 2020-000442, with Buellia disciformis (Fr.) Mudd, Buellia sp., Catillaria nigroclavata (Nyl.) J. Steiner, Lecanora megalocheila , Lecidella euphorea , Rimularia cf. caeca , Rinodina sp. (BDNA-L-0000642; GenBank MW832792 for ITS) .

Figures

Figure 2. Phylogenetic relationships amongst available species in the Lecanora symmicta group based on a Maximum Likelihood analysis of the dataset of ITS sequences. The tree was rooted with five sequences of the Lecanora subfusca group and Tephromela. Maximum Likelihood bootstrap values ≥ 70 % and posterior probabilities ≥ 95 % are shown above internal branches. Branches with bootstrap values ≥ 90 % are shown in bold. The new sequences of Lecanora parasymmicta and Lecanora symmicta produced from this study are presented in bold, and all species names are followed by the GenBank accession numbers. Reference Table 1 provides the species related to the specific GenBank accession numbers and voucher information.

Figure 3. Phylogenetic relationships amongst available species in the Lecanora symmicta group based on a Maximum Likelihood analysis of the dataset of the mitochondrial small subunit (mtSSU) sequences. The tree was rooted with four sequences of the Lecanora subfusca group. Maximum Likelihood bootstrap values ≥ 70 % and posterior probabilities ≥ 95 % are shown above internal branches. Branches with bootstrap values ≥ 90 % are shown in bold. The new species Lecanora parasymmicta is presented in bold, and all species names are followed by the GenBank accession numbers. Reference Table 1 provides the species related to the specific GenBank accession numbers and voucher information.

Figure 6. Lecanora parasymmicta morphology (BDNA-L- 0001235, paratype in A BDNA-L- 0001220, holotype in B-M) A-C habitus and apothecia, thalline margin of apothecia consistently absent from the beginning D blackish hypothallus (red arrows) E apothecia in vertical section F biatorine apothecia without thalline margin G-J clavate asci with eight spores K ascospores constantly simple but rarely 1 - septate L immersed pycnidia M thread-like, curved pycnoconidia. Scale bars: 1 mm (A-D); 200 μm (E); 50 μm (F); 10 μm (G-K); 100 μm (L); 10 μm (M).