Caloplaca phlogina (Ach.) Flagey morphotype maritime.
Caloplaca citrina var. phlogina (Ach.) H. Olivier
Thallus crustose, 1-2 cm in its greatest length, rather thin and not very visible, more or less smooth, light gray, yellowish gray, but quickly granular-powdery by soredia more or less arranged in areoles, yellow to greenish-gray depending on the exposure. Apothecia numerous, 0.2-0.4 mm in diameter, sessile, flat disc, yellow, orange-yellow, margin persistent, sorediate at least at the beginning, concolor or a little paler. 8-spore asci. Colorless, polarilocular spores, 10-13 x 6-7 µm according to the literature with a septum of 3-5 µm, (9) 10-13 (15) x 6-8 (9) µm according to our measurements. Often branched or forked paraphyses, with swelling at the top. Photobiont: Trebouxia. Thallus; K-, apothecia: K + purple. Nitrophilic and halophilic taxon typically occurring atop beaches in woody debris, driftwood, kelp stems, etc. but also on twigs, roots, etc. of shrubs from the seaside areas. Species variously interpreted by the authors of which there seem to be two taxa: a maritime from the seaside, here presented and another from the interior different by its appearance and its habitat. N.B. These two taxa might deserve to be separated at a higher level than the morphotype ... N.B. the soredia are sometimes so numerous that this species then looks like Caloplaca limonia which occure in a different habitat! Cf. Caloplaca chrysophtalma which occure in the same habitat and which is perhaps only this sterile species or with few apothecia, Caloplaca sorediella which also occure in the same habitat but whose thallus is K + purple; Caloplaca suaedae with a slightly olive warty thallus which usually occurs on Suaeda vera and Caloplaca pyracea with more apothecia and more vivid colorings.