This paper is a study of the ombrophobous saxicolous lichen vegetation along the coasts of southwestern Europe and northern Africa, with some comments on the bioclimatic features of this area. All taxa mentioned in the text are included in a commented list. The species considered as characteristic or transgressive of ombrophilous communities are provided with a comment on their distribution, ecology and syntaxonomy. Distribution maps are provided for some little known species.
On the basis of the phytosociological approach 6 associations and 2 communities are recognized, according to the following syntaxonomic scheme:
Roccelletea phycopsis Class. proy. Saxicolous, ombrophobous, thermophytic, aerohygrophytic, halotolerant, photophytic to skiophytic, scarcely to not nitrophytic.
Littoral or sublittoral areas, in Europe and northern Africa.
Dirinetalia massiliensis Ord. prov. On carbonatic rocks. Mediterranean and Eurosiberian regions.
Roccellion phycopsis Egea et Llimona em. On carbonatic rocks. Optimum in the Mediterranean region.
Dirinetum repandae Clauzade et Roux 1975. Littoral or sublittoral areas, in the infrathermo-mesomediterranean and thermocolline stage.
? Community of Opegrapha durieui On porous more or less soft rocks near the sea.
Thermomediterranean.
Roccelletalia fuciformis Ord. prov. Siliceous and volcanic rocks. Macaronesian,
Mediterranean and Eurosiberian regions.
Roccellion tinctoriae Klement 1965. On vertical and overhanging cliffs, very
aerohygrophytic, photophytic. Optimum in the Macaronesian region. Present also in high air moisture areas of the Mediterranean and Eurosiberian regions.
Roccelletum tinctoriae Klement 1965. Shaded volcanic rocks. Infra- thermo-Mediterranean-Canarian. From arid to humid ombroclimate.
Lecanactidion monstrosae Ali. prov. Acidophitic, anombrophytic, from photophytic to very skiophytic, less aerohigrophytic than the former alliance. Littoral of the Mediterranean, Macaronesian and southern half of the Eurosiberian region.
Dirinetum africanae Egea et Llimona 1984 corr. Siliceous and volcanic rocks. On cavities, small caves, overhanging and vertical cliffs thermo (meso ?)- Mediterranean and infrathermocanarian. From arid to dry ombroclimates.
Lecanactino plocinae-Dirinetum sorediatae Egea et Rowe 1987 Sandstone and schists. Coast and sublittoral hills of Cadiz and Tanger. Thermomediterranean subhumid (humid ?).
Sclerophytetum circumscriptae James, Hawksworth et Rose 1977 Southern part of the Eurosiberian region. Siliceous rocks.
Lecanactino monstrosae-Dirinetum insulanae Ass. nova. Volcanic rocks. Infrathermomediterranean-canarian, (thermocolline?). Ombroclimate arid to subhumid.
The ecology, distribution and floristic composition of all syntaxonomic units are discussed.
