Flavoparmelia caperata (L.) Hale forma caperata forme corticole
Parmelia caperata (L.) Ach.
Thallus rosette-shaped, loosely appressed, to 20 cm diam., made of lobes, 5-12 mm wide, enlarged and rounded at apices, transversally wrinkled or crumpled (as badly ironed), grey-yellowish, yellowish when dry, green-yellowish, green-apple when moist, often coarsely corrugate, surface entirely covered, and notably towards the center, with granular soredia around pustulate soralia, 0.5-3 mm diam., lower surface blackish towards the center, margins brownish with simple rhizines. Apothecia rare, pustulous at first, then sessile, to 8 mm diam., disc concave, brown-red, exciple markedly sorediate, concolourous to the thallus. Ascospores colourless, ellipsoid, 15-24 x 9-12 µm. Photobiont: Trebouxioid. Cortex : K-, Medulla and soredia: K- or dull yellow, KC +/- red or slightly orange, never red,, KC+/- reddish, Pd+ pale red-orange, Not especially maritime but abundant in our prospection area on well-lit rocks or heaths in the aerohaline zone, also on bark of trees. N.B. Not to be confused (although rather difficultly in absence of chemical spot tests) with the much rarer Flavoparmelia soredians that has clear oceanic trends and a medulla K+ yellow turning red, the two species potentially growing in combination. Several morphs of this highly variable species are worth to be mentioned: Flavoparmelia caperata f. papillosa of which the thallus and apothecia exciple are covered with small verrucose isidia, 0.2-0.5 mm diam., and Flavoparmelia caperata f. laevissima of which the thallus is devoid of verrucose isidia and of soredia. N.B. When pseudocyphella can be observed, and C+ red, see Flavopunctelia flaventior.