In North America, it is found at low elevations in riparian areas with coastal influence, while in Europe, where it is extremely rare, it occurs in montane-oceanic regions and shows a preference for basic rock substrates.

Lohtander and colleagues (2002) found high genetic variability in both nuclear and mitochondrial DNA regions that corresponded with morphological and chemical variation, suggesting the presence of multiple distinct species within what was then considered N. helveticum sensu lato.

[4] The application of the name N. helveticum remains somewhat uncertain, as the type specimen from Switzerland has never been found again in that country, leading some researchers to speculate that the original material may have been mislabelled.

[3] In Nordic countries, where the species complex has been extensively studied, N. helveticum sensu stricto is known from approximately 20 localities across Finland, Norway and Sweden, while N. tropicum is known from just a single Norwegian location.

In North America, it typically occurs in moist, shady environments at low elevations, particularly in old-growth riparian forests and areas with strong coastal influence.

The species demonstrates a strong preference for basic rock substrates in Scandinavia, though it can occasionally be found growing as an epiphyte on trees.