Lecanora atro-ocellata Bungartz 2020, sp. nov.
Creators: name: Bungartz, Frank
name: Elix, John A.
name: Printzen, Christian
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Fungi
Ascomycota
Lecanoromycetes
Lecanorales
Lecanoraceae
Lecanora
Lecanora atro-Ocellata

description: Lecanora atro-ocellata Bungartz sp. nov. MycoBank no. 833369
Diagnosis. Thallus deep yellow, similar in color to L. pseudopinguis, but differs in having subsquamulose areoles and deep olivaceous brown to bluish black apothecial discs.
Type:— ECUADOR. GALÁPAGOS: Isabela, Volcán Darwin, southwestern slope, above Tagus Cove, 0˚13’43.3’’ S, 91˚19’47.3’’W, 724 m alt., transition zone, SW-exposed lava flow of weathered AA-lava with scarce vegetation (Macraea laricifolia, Dodonaea viscosa, Croton scouleri, Cordia revoluta and Jasminocereus thouarsii), exposed basalt rock, 12-Nov-2007, Ertz, D. 11821 (CDS 37180– holotype).
(Fig. 8A–C)
Thallus saxicolous, moderately thickened, areolate, of dispersed, rarely ±contiguous irregularly convex to somewhat granular, often slightly subsquamulose areoles; surface deep greenish yellow to greenish beige or yellowish ochraceous, ±roughened, matt, epruinose, lacking soredia, prothallus absent. Apothecia numerous, ±aggregated, circular to slightly irregular in outline, sometimes deforming one another, 0.2–0.6(–0.8) mm in diam., semi-immersed, emergent to adnate, eventually sessile and then ±constricted below, initially cryptolecanorine, but soon becoming lecanorine with persistent, crenate to strongly verruculose, epruinose margin, concolorous with the thallus; disc plane to ±convex, deep olivaceous brown to bluish black, appearing matt for its indistinct, hyaline pruina; hymenium hyaline, not inspersed; epihymenium ±granular, but lacking distinct crystals, with a diffuse, aeruginose pigment (cinereorufa -green: intensifying in K, HCl+ bluish green, N+ reddish violet); proper exciple thin, indistinct, with few small crystals; thalline exciple thick, distinctly corticate, with many large crystals not dissolving in K and sparse small crystals dissolving in K; hypothecium hyaline; ascospores 8/ascus, simple, broadly ellipsoid to subglobose, (7.8–)8.9–12.5(–18.6) × (3.9–)5.0–7.2(–8.8) µm (n = 45). Pycnidia not seen.
Chemistry: Thallus cortex including apothecial margin P−, C+ orange, KC+ orange, K−, UV− (dull or deep orange); with atranorin [major], arthothelin [major], isoarthothelin [minor]; [specimen analyzed with TLC: Bungartz, F. 6786 (CDS 36205)].
Etymology: With its dark greenish black discs, the epithet atro-ocellata meaning “with small black eyes” seems appropriate; the hyphenation is used here in accordance with ICBN Art. 60.9.
Ecology and distribution: Known only from the Galapagos, from the transition through the humid to the high altitude dry zone, on steep rock surfaces (large boulders, steep cliffs), typically in ±sheltered, semi-shaded, rarely exposed to sunny habitats.
Notes: Because of the black apothecial discs, the species could at first glance be confused with Buellia mamillana (Tuck.) W.A. Weber, a species that initially has similar lecanorine apothecia becoming lecideine only with age. Thalli of L. atro-ocellata, however, are a much deeper yellow-ochraceous color and they are composed of discrete, distinctly separate, often dispersed and ±subsquamulose areoles. The areoles do not become elongated like those of Buellia straminea Tuck., a species which is very similar in color, but always with distinctly lecideine apothecia. If examined with the microscope, both Buellia species are easily distinguished from L. atro-ocellata due to their pigmented, septate ascospores.
Among the Galapagos-species of Lecanora, L. pseudopinguis is most similar in color, but that species has significantly larger apothecia, with a disc never blackened and a more contiguous thallus.
Additional specimens examined (paratypes). ECUADOR. GALÁPAGOS: Isabela, Volcán Darwin, southwestern slope, above Tagus Cove, 0˚13’43.27’’ S, 91˚19’47.27’’W, 724 m alt., transition zone, SW-exposed lava flow of weathered AA-lava with scarce vegetation (Macraea laricifolia, Dodonaea viscosa, Croton scouleri, Cordia revoluta and Jasminocereus thouarsii), on rock, 12-Nov-2007, Bungartz, F. 7408 (CDS 37895); 7427 (CDS 37914); Ertz, D. 11806 (CDS 37165); 11821 (CDS 37180); ca. 1.5 km from the southwestern crater rim, 0˚12’20.5’’ S, 91˚18’52.77’’W, 1280 m alt., high altitude dry zone, basalt outcrop for the most part bare of vegetation, on rock, 14-Nov-2007, Bungartz, F. 7584 (CDS 38080), 7593 (CDS 38089); Volcán Sierra Negra, top of the northern crater rim, 0˚48’3’’ S, 91˚5’25.89’’W, 968 m alt., humid zone, SW-exposed basalt cliffs among dry vegetation of grasses and herbs, on rock, 08-Sep-2007, Bungartz, F. 6784 (CDS 36203), 6776 (CDS 36195), 6786 (CDS 36205); Volcán Chico on the norteastern slope of Sierra Negra, 0˚46’56.77’’ S, 91˚6’4.298’’W, 938 m alt., transition zone, young lava flow with very scattered vegetation (Macraea laricifolia, Darwiniothamnus tenuifolia), on rock, 14-Aug-2008, Bungartz, F. 8166 (CDS 40812).
description: Published as part of Bungartz, Frank, Elix, John A. & Printzen, Christian, 2020, Lecanoroid lichens in the Galapagos Islands: the genera Lecanora, Protoparmeliopsis, and Vainionora (Lecanoraceae, Lecanoromycetes), pp. 1-85 in Phytotaxa 431 (1) on pages 26-28, DOI: 10.11646/phytotaxa.431.1.1, http://zenodo.org/record/13877123