Lichens marins - Lecanora rupicola (L.) Zahlbr. subsp. subplanata (Nyl.) Leuckert & Poelt morph. formant des mosaïques.

Lecanora rupicola (L.) Zahlbr. subsp. subplanata (Nyl.) Leuckert & Poelt morph. formant des mosaïques.

Synonyms:

Family: LECANORACEAE

Habitat: Aerohaline zone

Description

Thallus crustose well defined reaching 8 cm across, cracked surface, more or less rough and bumpy, chalky, limestone-white, whitish, greyish-white, prothallus black, narrow, clearly visible in the mosaic of several or when in contact with other crustoses species. Apothecia numerous, immersed in the thallus, rarely a little protruding by their margin, 1 to 2 mm in diameter, discs flat, whitish to cream but which may appear pale grayish to dark gray by the strong bloom which covers them, sinuous margin that may be a little prominent and appear a little raised on the thallus, whitish or paler, entire to crenate. Simple spores, elliptic, 9-15 x 5,5-7 µm according to literature, 12-15 (18) x 5-8 µm according to our measurements. Photobiont: green algae. Thallus: C- or C+ orange, K+ yellow, P- or P+/- yellow ; apothecia disc : C- or C+ orange (because the usual bleach solution contains NaOH), KC+ orange. Species with strong coastal affinities, growing on not too acidic and sheltered siliceous rocks, often under overhangs, common in the xeric supralittoral zone where it can form large mosaic colonies, also frequent in the aerohaline zone, even further inland.

N.B. Parasitism by Arthonia varians is very frequent, which facilitates the recognition of Lecanora rupicola subsp. subplanata, even in case of partial parasitism, by its black parasitized apothecia mixed with non-parasitized apothecia which are KC+ orange. On the other hand, it becomes very difficult to recognize this species in the event of a thallus rendered completely sterile by its parasite, especially if it is an isolated thallus far from a colony, in this case only the reaction of the yellow K+ thallus will direct towards Lecanora rupicola s.l..

N.B. The colored chemical reactions reported here are variously interpreted by the authors and there is great confusion on this subject, with regard to the specimens tested in our prospecting area (siliceous coastal rocks) they are most often C+ orange and KC+ orange on the discs of the apothecia, which does not completely correspond to the indications appearing in the literature (particular "marine" chemotype?), the C- specimens are rarer.

N.B. This subspecies is also variously interpreted by authors (and even ignored) we describe it here according to the interpretations of ancient local lichenologists.