World distribution: According to Degelius (1954, 1974, 1986) the species occurs in Europe, Africa (Morocco), and North America. In Europe, it is widely distributed in areas with calcareous bedrock, occurring in Fennoscandia, the British Isles, Central and South Europe where it occurs mainly in the mountains and is rare in the lower part of the Mediterranean area (Degelius 1954). In Italy, the species is rare and has an optimum in areas with submediterranean vegetation (Nimis 1993). In Sweden the species is more or less common on Öland and Gotland, and also occurs on the coast of Södermanland and Uppland, as well as in one inland locality in Västmanland (by the shore of a lake; Degelius 1954). In Finland, the species occurs on the Baltic island Korpo (Regio aboënsis; Vitikainen 1991)
Ecology: Results. The substrate (indicated in 14 localities) was Cambro-Silurian sedimentary rocks of the geological 'Oslo Region', possibly exclusively limestone. The habitat (indicated in 10 localities) was fully exposed to somewhat shaded (pine forest), south- to west-facing, weakly inclined to vertical rock faces. With one exception (79), all localities were apparently situated within a few hundred meters from the sea or large lakes; some localities were in maritime situations. Discussion. Degelius (1954) discussed the ecology of C. multipartitum on a European scale: It is restricted to bare calciferous rock, in particular limestone, sometimes it occurs on dolomite or schist, but rarely on siliceous rocks. The species mainly occurs in fissures and depressions, sometimes even periodically inundated, but is rare in the shade. The habitats may be horizontal to more or less vertical, and include maritime ('lower aerohaline belt') and lacustrine rocks
Threats: Results. Threats were noted at five of the nine investigated localities: by air pollution (75, 2432), building on the site (75, 2826, 3475), and trampling (2826, 2827). Discussion. Since it mainly grows on exposed, south- to west-facing rocks near the sea in the most densely populated part of the country, we assume that some populations may be threatened by fragmentation and abrasion due to human activities (81, 2421, 2826, 2827, 3089). Some localities in Telemark (at least 75, 2432) are within an area of local air pollution where the surrounding corticolous lichen flora shows signs of damage. One locality (80) is situated on an island which is now a huge quarry, and it is doubtful if the species is still present. In one locality (79), it was sought for in vain in the early 1980's; the site is close to a development area
Status: The species was investigated in 4 old localities and found to be present at all. Five new localities were discovered. Locality 76, and possibly 74, are within nature reserves
Specimens in other herbaria, litterature, etc.