A Tylophorone hibernico thallo leviore et crassiore cremeo differt.
Type: Ecuador, Galapagos Islands, Isabela, Volcán Darwin, southwestern slope, above Tagus Cove, 724 m, transition zone, SW-exposed lava flow of weathered AA-lava with scarce vegetation (Macraea laricifolia, Dodonaea viscosa, ...), on rock, overhang, 2007, D. Ertz 11794 (CDS 37153–holotype; BR, herb. Diederich–isotypes).
Description: Thallus crustose, superficial, more or less smooth, creamy white to pale brownish, ecorticate, thin, up to 0.5 mm thick; hyphae irregularly branched, hyaline, mainly 2–2.5 µm diam., forming numerous convex to subglobose sporodochia 0.5–1 mm diam., which are similar in colour, but paler than the thallus. Sporodochial conidia hyaline, smooth to slightly roughened, mostly simple, more rarely 1-septate, with rounded or truncate apices, spherical, ellipsoid or rarely oblong, simple conidia (4.5–)5–6.5(–9) × (3–)3.5–4.5(–5.5) µm, l/b ratio 1.1–1.9 (n=60), 1-septate conidia (7–)8–11(–15) × (3–)3–4.5(–6) µm, l/b ratio 2–3.2 (n=70). Prothallus whitish cream, byssoid, 0.5–1 mm wide. Photobiont Trentepohlia. Ascomata densely covering the thallus of one specimen (Aptroot 65477), but all mazaedia composed of degenerated ascospores and brownish hyphae, no intact ascospores found. Pycnidia unknown.
Chemistry: thallus C+ red, K–, KC+ red, P–, UV–. Sporodochia C+ red, K+ yellow, KC+ red, P–, UV–. TLC: lecanoric acid in all specimens examined; in addition, a pale orange substance in daylight after heating in Ertz 11794.
Notes: The new species is distinguished from T. hibernicum by a smoother and thicker, more compact thallus, which is always distinctly cream coloured. Furthermore, the C+ red reaction of the thallus is always stronger than in T. hibernicum. In some specimens of T. galapagoense (e.g., Bungartz 8749 and 8750) the majority of conidia are simple (Fig. 3G), contrary to T. hibernicum in which one-septate conidia usually dominate (Fig. 3F). However, in other specimens of both species, a mixture of one-septate and simple conidia occurs. Overall, even within sporodochia that predominantly produce one-septate conidia, a few simple conidia can typically be found, and vice versa. Because one-septate conidia easily fracture, it is difficult to assess if the formation of simple vs. one-septate ones follows a different conidiogenesis. Specimens that produce mostly simple conidia generally have conidia with a more spherical shape, whereas simple conidia derived secondarily from septate ones that broke apart, are typically more elongate, with an oval to ellipsoid, not spherical shape. Overall we could not find any clear correlation of these differences with a particular species, and the predominance of simple vs. one-septate, spherical vs. elongate conidia may perhaps be related more to environmental factors than to genetical factors.
Tylophoron galapagoense is currently known only from Galapagos, on five different islands, where all specimens have been found growing on rock below shaded overhangs or in crevices, from the coast through the dry lowland forests to the transition zone. Only in Santiago the species has also been found in the humid highlands, where it is known from hidden crevices of the dry, N- NE-exposed steep crater rim of Cerro Gavilan. On Volcán Darwin, where the type specimen was collected, the western slopes of the volcano lie within the rain-shadow of Fernandina. Here the vegetation is generally dry and the transition zone reaches unusually high altitudes. Where on the opposite sides of the island humid forests abound, the dry lava flows on the western slopes are characterized by low, transition zone shrubs. In contrast, the corticolous T. hibernicum, although occasionally found in the transition zone, appears more common in the humid forests of the Galapagos highlands.
Additional selected specimens examined: Ecuador, Galapagos Islands: Santa Cruz island: along dirt road to Mina Granillo Rojo, off the main road to the channel, 583 m, transition zone, dry deciduous forest with basalt outcrops in between on N-slope of island, on sheltered rock face, 2007, D. Ertz 11576 (BR); ibid., F. Bungartz 7113 (CDS 37598); Mina Granillo Rojo, on the N-side of the island, above the mine, 633 m, transition zone, lava outcrop in open forest, ENE-exposed overhang (70°–80°) of basalt boulder in rock outcrop, on volcanic rock, 2010, F. Bungartz 8749 (CDS 44629); ibid., F. Bungartz 8750 (CDS 44630). Isabela island: Volcán Alcedo, along the trail going up the E-slope, basalt rubble field to the SE-side of the trail and the barranco, 530 m, dry zone, basalt rubble field with scattered vegetation, 2006, A. Aptroot 64943 (CDS 31522); Volcán Sierra Negra, Cerro Orchilla, ca. 4 km W of Puerto Villamil, 56 m, dry zone, S exposed slope of hill, open Bursera graveolens forest, SE-exposed overhang of basalt outcrop, 2008, Bungartz 8449 (CDS 41095). Pinta island: SW-part of the island, along trail going up the SW slope to Las Pampas on the western saddle, 316 m, transition zone, open forest, top of basalt boulder, 2008, Nugra 564 (CDS 38942). Santiago island: summit of Cerro Gavilan, inner N- and NE-exposed crater rim, 840 m, humid zone N- and NE-exposed, steep basalt cliffs of crater rim with ferns growing in crevices, 2006, A. Aptroot 65760 (CDS 32352). Pinzón island: along the trail going up from Playa Escondida, N- to W-facing cliff above a crater, 318 m, dry transition zone with Cordia lutea, Croton scouleri, and at the bottom of the cliff also Scalesia baurii ssp. baurii, 2006, A. Aptroot 64030 (CDS 30591).
from: Ertz, D., Bungartz, F., Diederich, P. & Tibell, L. (2011) Molecular and morphological data place Blarneya in Tylophoron (Arthoniaceae). Lichenologist. 43(4): 1–12.