Diagnosis. A species with dark orange to rusty-orange apothecia on a lead- to olive-gray, rimose to rimose-areolate thallus, superficially similar and closely related to Lacrima sonorae from California, but distinguished by its different ITS sequence.
Type. Ecuador, Galápagos: Isabela, Volcán Alcedo, outer S-exposed crater rim, 0°12′23″S, 90°47′4″W, 814 m alt., humid zone, S-exposed, steep basalt cliffs of crater rim with ferns (Pityrograma calomelanos var. calomelanos, Polypodiumtridens, Dryopteris palmata, Adiantum concinnum, Blechnum polypodioides) growing in crevices, on rock, 24-Mar-2006, Bungartz, F. 4813 (CDS 28977‒holotype; GenBank Accession number nrITS: MT967404).
Description. Thallus rimose to rimose-areolate, areoles mostly flattened, rarely with subsquamulose edges, effuse, but typically delimited by a compact, ± zoned prothallus; surface pale to lead or olive-gray, smooth, not shiny, in parts with a fine farinose, whitish pruina, lacking vegetative propagules, but the thallus center occasionally ± nodular from abundant apothecial initials. Apothecia numerous, often closely adjoining and ± deforming one another, sessile, basally ±constricted, up to 1 mm in diam., biatorine (to indistinctly ‘zeorine’); proper margin persistent, prominent, thick, ~160 μm wide, dark orange to ferruginous (‘rust-colored’), epruinose or ± covered by the same pruina as the disc, thalline margin absent or extremely thin, gray, ± concolorous with the thallus or pale yellow (particularly the immature, nodulose apothecial initials); disc plane to eventually slightly concave, concolorous with the proper margin, densely covered by a coarse rusty orange-red, C+ deep red, K+ purple pruina; epihymenium orange brown, with both a diffuse orange-brown pigment, as well as orange pigment granules, C+ red, K+ purple, contiguous with the outer exciple; hymenium hyaline, not inspersed; proper exciple lacking crystals, differentiated into a broad hyaline inner part, and an orange-brown outer part, brown pigmentation diffuse, orange pigment granules C+ red, K+ purple; subhymenium and hypothecium not differentiated, hyaline, not inspersed; asci clavate, Teloschistes-type; ascospores 8/ascus, polaribilocular, oblong to ellipsoid (8.9–)10.6–13.1(–15.4) × (6.0–)6.4–7.7(–8.3) μm, with a thick, (3.4–)3.9–5.6(–7.0) μm wide septum (n = 45). Pycnidia unknown.
Chemistry. Thallus P–, K–, C–, KC–, UV– (dull); apothecia P–, K+ purple, C+ red, KC+ purple to ± reddish, UV– (dull); no secondary metabolites detected in the thallus, apothecia with equally high proportions of 7-chloroemodin and fragilin, typically present in lower concentrations as accessory are 7-chlorocitreorosein, 7-chloroemodinal and emodin.
Etymology. Named after the Galapagos Islands, where the species is moderately common and possibly endemic.
Ecology and distribution. Known only from the Galapagos, where it grows on sunny to semi-shaded, wind and rain-exposed rock, mostly in the upper transition and humid zone, occasionally also in the dry zone and rarely near the coast.
Note. This taxon is very uniform concerning its ITS. Genetically, the closest neighbor is the morphologically similar ‘Caloplaca’ sonorae (here also placed into Lacrima, see below). Wetmore (2007a) reports Lacrimasonorae from southwestern North America (Arizona, Baja California Sur, western Chihuahua, and Sonora); according to the Consortium of North American Lichen Herbaria, specimens have also been found in southern California (USA), but the species remains unknown from outside the Sonoran Region. Lacrima galapagoensis differs by slightly shorter ascospores (10.6–13.1 μm) compared with Lacrima sonorae (12.5–15.5 μm). ITS sequences are sufficiently distinct to justify separation at the species level. In Galapagos, Lacrima galapagoensis is most closely related to L. epiphora, and L. aphanotripta.