Type: ECUADOR. Galapagos: Santiago Island, ca. 5 km inland from the E-coast; 0° 16' S, 90° 37' W; Bungartz 5208 (CDS 29421, holotype).
Diagnosis: Differing from R. chilensis in the mostly unbranched, prominent, partly open ascomata, verrucose periphysoids, and narrower ascospores.
Description: Thallus areolate, whitish gray, becoming yellowish white in the herbarium; surface smooth, epruinose. Apothecia prominent, rounded to shortly lirellate; lirellae broad and short, thickened, unbranched or rarely sparsely branched; labia thick, entire, black, basally with thalline margin, apically and along the rim with distinct pruina formed by layer of periphysoids; disc usually concealed but expanding with age; excipulum completely carbonized, carbonization extending below the hymenium; hymenium hyaline, clear (not inspersed), I– (rarely faintly bluish laterally along the excipulum), 90–120 μm high; ascospores 8 per ascus, ellipsoid to oblong, 15–17(–20) × 4–5 μm, submuriform with 5–6 transverse septa and 1–2 longitudinal septa per segment, with thickened septa and lens-shaped to rounded lumina, hyaline, I–.
Chemistry: Norstictic acid, thallus K+ yellow turning red (forming needle shaped crystals under the microscope).
Habitat: Growing saxicolous along the coast underneath wind- and rain-sheltered, shaded overhangs.
Notes: This new species is recognized by its rather prominent, partially open ascomata, the verrucose periphysoids, and the rather narrow ascospores. The verrucose surface of the periphysoids is different in appearance from the spinulose surface found in Carbacanthographis (Staiger 2002), a fact that supports our conclusion that the two genera are not closely related and do not have shared synapomorphies. Redonographa galapagoensis appears to be endemic to the Galapagos Islands; it was previously reported as Carbacanthographis saxiseda (Bungartz et al. 2010), but was found to represent an undescribed taxon.