World distribution: The species (see notes) is known from the Canary Islands, South and West Europe north to Norway (Purvis & James 1992d), and the Himalayas (D.D. Awasthi 1988). In the British Isles it is widespread and locally abundant (Seaward & Hitch 1982). The Fennoscandian its distribution canariensis not well known, as the taxonomy is not clear (see Notes). When broadly circumscribed, it is known from southern Sweden, Denmark, and Norway (Jølle 1977, Krog & James 1977). It is endangered in Denmark (Alstrup & Søchting 1989)
Ecology: Results. The single Norwegian collection dates from 1976 and was made from a trunk of a dead Acer pseudoplatanus in a small, mixed stand of A. pseudoplatanus and Ulmus glabra (Jølle 1977). Other species on the same trunk included Evernia prunastri, Flavoparmelia caperata, Hypogymnia physodes, H. tubulosa, Melanelia elegantula, Parmelia omphalodes, Parmotrema chinense, Physcia spp., Physconia spp., Platismatia glauca, Pseudevernia furfuracea, Punctelia subrudecta, Ramalina farinacea, and Xanthoria parietina (Jølle 1977). Discussion. While the related Ramalina obtusata occurs in moist, old-growth spruce forests, this species occurs mainly in well-lit habitats on isolated broad-leaved deciduous trees (Krog & James 1977). In Britain it is very common both on rock and trees near the coast. It prefers sunnier and drier habitats than most other representatives of the genus (Seaward & Hitch 1982)
Threats: Results. None. Discussion. The species was found on one dead trunk in an apparently intact environment (Jølle 1977). Random extinction is a general threat to so small populations. In Britain and Denmark the species is considered to be extremely sensitive to air pollution (SO2 and inorganic fertilizers; Seaward & Hitch 1982, Alstrup & Søchting 1989)
Status: The exact site was not located during the investigation. The trunk from which the collection was made, was dead already in 1976. The locality is not protected
Notes: Both the label and Jølle (1977) indicate the UTM grid reference as LL 03 03, the label also indicate the locality as 'Nesheim ved Nærbø'. The three neighbouring farms Nesheim are all in LL 02-03 08, however, and there are no Nesheim in LL 03 03 on the M711 map. Krog & James (1977) included two chemical strains under the name R. baltica, the strain with divaricatic acid, to which the Norwegian specimen belongs, is concentrated in western Europe, the strain with substances of the evernic acid complex mainly occurs in eastern Europe. In southern Sweden both strains occur. Recently, Purvis & James (1992d) assigned the Norwegian specimen to R. canariensis. If the two species are considered conspecific, the name R. canariensis has priority over R. baltica. Ramalina canariensis s. lat. has frequently been mistaken for R. obtusata (see discussion of R. baltica in Krog & James 1977). Ingelög et al. (1993) refer all Swedish specimens of the R. baltica/R. canariensis complex to R. obtusata, but Aronsson et al. (1995) distinguish between R. baltica and R. obtusata. Here R. obtusata is treated separately..
Specimens in other herbaria, litterature, etc.