Mycobank MB 517745
Thallus fruticulose, composed of mostly vertical, terete to rarely flattened, moderately branched, isidia-like lobules dispersed among mosses or cyanobacteria and sometimes forming up to 2 mm high, compact cushions; vertical lobules 60–100 µm thick and up to 1500 µm high, slightly moniliform, at the thallus edge slightly flattened and more horizontal, color vivid orange yellow to vivid orange with uneven, matt surface. Photobiont trebouxioid. Apothecia sparse, embedded between the lobes, 0.8–1.5 mm with regular to flexuouse margin, initially zeorine with a proper margin concolorous with disc and an isidiate thalline margin concolorous with thallus, later lecanorine with an elevated margin, which is often obscured by isidia; disc deep orange, darker than thallus, flat; episamma medium coarse. Exciple fan shaped, laterally ca. 80 µm, centrally ca. 20 µm. Hymenium 60–100 µm; paraphyses branched with slightly thickened end cells, up to 4 µm. Asci clavate with 8 spores. Spores ellipsoid, polarbilocular, (12.5–)13–16(–18) x (5–)6–7.5(–8) µm; septum narrow, (1–)1.5–2.5(–3.5) µm. Pycnidia not observed. Secondary chemistry (HPLC): parietin (major), teloschistin (minor), fallacinal (minor), parietinic acid (minor), emodin (minor); conforms to chemosyndrome A according to Søchting (1997).
The genus Caloplaca is one of the largest lichen genera with probably close to 1000 species, particularly in cool regions favoring especially calcareous or nutrient rich substrata or maritime rocks. The cool parts of the Southern Hemisphere are still poorly studied. Caloplaca digitaurea is one of a number of undescribed species discovered during recent field work in Southern Patagonia as part of the Spanish ANTRAX project. It is characterized by the vivid orange, thick and terete isidia-like lobules, often in microfruticose clusters. The lobules are mostly distinct, always growing ± vertically upwards. The species can resemble C. isidioclada Zahlbr., but C. digitaurea has thicker lobules (up to 100 µm) than C. isidioclada (30–60 µm). Based on available ITS sequences and morphology, C. wetmorei Nimis, Poelt & Tretiach from the Sonoran Desert seems to be the closest relative. It has, however, smaller apothecia (0.3–0.4 mm) and a parasitic life habit (Nimis et al., 1994). Also, even though C. wetmorei may be a relative, there is only a 93 % similarity between the ITS region of the nuclear rDNA of the two species (C. digitaurea Genbank number HQ 317922, C. wetmorei, isotype Genbank number HQ 317923). Therefore it is unlikely that they belong to the same taxon.
The epithet digitaurea refers to the golden, finger-like isidia with a slight reference to the James Bond blockbuster movie Goldfinger from 1964. Its English vernacular name would be Goldfinger Fire Dot Lichen.
Chile, Province Última Esperanza and Province Antárctica Chilena, Isla Navarino. On rock, detritus and over other lichens on exposed outcrops in shrub vegetation, and grassland by coast, but not maritime, 5–170 m. altitude.
Type:—CHILE: XII Región de Magellanes y de la Antártica Chilena: 15 km N of Puerto Natales, Cueva del Milodón; 51°34’S, 72°37’W, 145 m; Jan 2005, Søchting 10.401 (holotype C).
Additional specimens examined (paratypes):—CHILE. XII Región de Magellanes y de la Antártica Chilena. Última Esperanza Province, Parque Nacional Torres del Paine, Søgaard 38 (C). Parque Nacional Torres del Paine. Walk from Lago Grey; Søgaard 43, 48 (C), Parque Nacional Torres del Paine, Lago Pehoe, Río Paine, 2 km NE of Laguna Linda; Elvebakk 97:468 (C). Antártica Chilena Province, Isla Navarino, 37 km W of Pto. Williams, Caleta Honde; Søchting 10.175 (C).
Sicut Caloplaca wetmorei sed apothecia majores et thallus non parasitcus..