World distribution: The species is reported from North Africa, South America, and Pakistan (Purvis & James 1992c). The European distribution area includes southern Scandinavia (Almborn 1948, map), The Netherlands, France, Central Europe (Wirth 1987, map), southern Europe, and the British Isles north to SE Scotland (James & Rose 1974a). It has an eastern tendency in the British Isles (Coppins 1976). Melanelia elegantula is rare in Sweden apart from Skåne (Ingelög et al. 1993), and a red listed species (V+) in Denmark (Alstrup & Søchting 1989)
Ecology: Results. Recorded substrates were: Acer pseudoplatanus (3), A. platanoides (1), Fagus sylvatica (1), Fraxinus excelsior (1), Aesculus hippocastanum (1) and, Populus tremula (1). The localities were, apart from one, situated within or near towns. Discussion. The ecological requirements of Melanelia elegantula are very similar to those of M. laciniatula, and the two species are often found in the same habitats (Almborn 1948, Barkman 1958, James & Rose 1974a). In The British Isles M. elegantula is much more frequent than M. laciniatula on major branches within the tree canopy, and the species withstands moderate eutrophication provided this is not accompanied by a substantial rise in substrate pH (James & Rose 1974a). Melanelia elegantula grows on acid bark (pH 3.8-4.6, James & Rose 1974a; Wirth 1987). In Britain, the species is becoming more common in relatively polluted areas (to 65 µg/m3 SO2, Purvis & James 1992c). In Scandinavia, Melanelia elegantula was previously most common on Fagus, Fraxinus, and Aesculus in parks, avenues, and on solitary trees near road or houses, and it never occurred inside forests (Almborn 1948). A recent study indicates that the more acidic bark of Fagus and Aesculus in southern Sweden is not any longer a suitable substrate and that the species is now mainly found on Acer, Fraxinus, and Ulmus; possibly as an effect of acidification (Thell 1989). Melanelia elegantula has been referred to the 'Xanthorion', but grows in habitats where genera like Phaeophyscia, Physcia, Physconia, and Xanthoria are of minor importance (Almborn 1948, Barkman 1958, James et al. 1977). It is obviously an invasive species which is still rapidly spreading over lowland areas of Britain (James & Rose 1974a). Its preference for cities indicates a similar tendency in Norway
Threats: Results. Assumed threat was storm felling (1). Discussion. The species is moderately resistant to SO2, and since it favours well-lit roadside trees, especially near small villages and towns, it should hardly be threatened. During a search for the species in southern Sweden, it was re-discovered on 15 of 34 old localities, and additionally found on as many as 12 new localities (Thell 1989), indicating a stable situation for the period 1948-1989. Since it has an invasive habit, it could well have spread to neighbouring localities also in southern Norway. Logging of large, solitary trees is recorded as a threat in Sweden (Ingelög et al. 1993)
Status: Two old localities were visited. It was found in one, while the status was uncertain in the other. One new locality was found. High abundance was recorded in two localities within the city of Stavanger. Melanelia elegans is probably a rare species in Norway, but insufficiently known since it is difficult to separate from the common Melanelia fuliginosa in the field
Notes: There has been a discussion if the mainly epiphytic M. elegantula is clearly separated from the mainly saxicolous M. infumata. Esslinger (1977) considers saxicolous specimens from inland sites in Norway to be M. elegantula, while floras and checklists (Krog et al. 1980, Santesson 1993) do not. The species was reported from Hå, Rogaland (3509, Jølle 1977). Since it was not mentioned in his later cand. real. thesis, and since no collection has been found in Norwegian herbaria, the locality is rejected..
Specimens in other herbaria, litterature, etc.