Synonyms: Caloplaca lobulata auct. non (Flörke) Hellb. nec (Sommerf.); Caloplaca marina (Wedd.) Du Rietz; Caloplaca salina Erichsen; Gasparrinia marina (Wedd.) Hav.; Placodium marinum (Wedd.) H. Olivier
Distribution: C - Sar (Neuwirth 2018). S - Si (Nimis & al. 1994).
Description: Thallus crustose, episubstratic, yellow to yellow-orange, very variable, continuous to rimose-areolate in central parts, forming orbicular to irregular patches to 3 cm in diam., sometimes delimited by a paler prothallus, the margins often indistinctly lobulate. Areoles (0.1-)0.2-0.7(-0.9) mm wide, mostly convex, often longer than wide, paraplectenchymatous. Apothecia zeorine, yellow-orange, often clustered, sessile when young but soon raised and strongly constricted at base, (0.2-)0.4-1.2(-1.7) mm across, with a concave to slightly convex, often uneven, orange disc, a slightly raised, smooth, often paler, (25-)50-100(-120) μm thick proper margin, and an up to 150 μm thick, flexuose to crenulate, sometimes finally excluded thalline margin. Proper exciple of radiating, thick-walled, tightly packed hyphae; epithecium orange-brown, granular, K+ red; hymenium colourless, (60-)70-95 μm high; paraphyses somewhat moniliform, simple to branched, 1-2(-3.5) μm thick at mid-level, the apical cells 4-7 μm wide; hypothecium colourless, sometimes inspersed with oil droplets. Asci 8-spored, cylindrical-clavate, Teloschistes-type. Ascospores 1-septate, polarilocular, hyaline, ellipsoid, (9-)10.5-15(-18.5) x (3.7-)4.5-7(-8) μm, the septum (1.8-)2.5-5(-6.5) μm thick (c. 1/3 of spore length). Photobiont chlorococcoid. Spot tests: thallus and apothecia K+ red, C-, KC-, P-. Chemistry: thallus and apothecia with parietin (major), fallacinal, emodin, teloschistin and parietinic acid (minor), corresponding with chemosyndrome A of Søchting (1997).
Note: a Mediterranean-Atlantic species in Europe, reported also from North America, growing on basic siliceous rocks, more rarely on calciferous sustrata in the salt-spray belt. According to Vondrák (in litt.), however, F. marina could be absent from Italy: the lichen with F. marina appearance from siliceous shores in Sardinia and Sicily is in fact a member of Haloplaca; pending the publication of the new data, I still maintain these records under F. marina. See also note on F. ora.
Growth form: Crustose
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual
Most common in areas with a humid-warm climate (e.g. most of Tyrrenian Italy)
[ABL 72957], Korea, Gangwon-do, Dist. Yangyang-gun, Hyeounbukmyeoun, Hagwangjeong-ri, around Hajodae, c. 38°01’ N, c. 128°44’ E, c. 4-20 m, on coastal siliceous rock. Leg. A. Aptroot 19.10.2014, det. A. Aptroot 2014.