Protoparmelia montagnei (Fr.) Poelt & Nimiz chemo. aquilina

      Thallus crustose 5-10 cm in its greatest length, irregular surface, cracked to areolate, light brown to brown at the beginning then becoming grayish, pale gray-brownish at the end by retraction of the cortex which lets appear the medulla by having the appearance of being scaly, very often blistered or with large folds, sometimes with areas of regeneration, hypothallus usually present, darker to blackish and preceded by a lighter area. Often numerous apothecia, at the beginning with a convex disc becoming flat then concave at the end, chestnut-brown (yellowish-brown at the end), a lighter margin in general more or less persistent. Numerous pycnidia. Medulla; K-, C + red, KC +, red, P-, UV + white (these colorations are sometimes difficult to demonstrate because they are disturbed by the remains of the thallus of the parasitized host). Typically on siliceous coastal rocks very exposed and subject to spray where this species parasitizes crustose lichens similar to the genera: Rhizocarpon, Lecanora, Aspicilia, Diploschistes, ... Can form large colonies in some places.

NB This lichen seems to have a very rapid evolution but very variable according to its host, it seems to wither away at the end of its parasitism but can regenerate it seems see: Protoparmelia montagnei chemo aquilina forme de régénérescence.

N.B. See Protoparmelia montagnei chemo. montagnei which is C-.

NB This taxon quite well characterized might deserve a higher rank than that of chemomorph ...