Adiantum capillus-veneris

Distribution

Adiantum capillus-veneris is native to humid warm temperate to tropical regions globally. It occurs in western and southern Europe (north to southern Scotland, where its northernmost sites are found), much of Africa, the Levant and across Asia to Japan, in Australasia, and in the Americas in the southern half of the United States from California to the Atlantic coast, through Mexico and Central America, to South America. There are two disjunct occurrences in the northern part of North America, at Cascade Springs in the Black Hills of South Dakota and Fairmont Hot Springs, British Columbia. In both instances, the warm microclimate created by hot mineral springs permits the growth of the plant far north of its normal range. It is similar in Zvonce spa resort (Звоначка Бања, Zvonačka Banja), near Pirot in Serbia, where hot mineral springs provide adequate heat and humidity for the survival of this species.

It is found in temperate climates from warm-temperate to tropical, where the moisture content is high but not saturated, in the moist, well-drained sand, loam or limestone of many habitats, including rainforests, shrub and woodlands, broadleaf and coniferous forests, and desert cliff seeps, and springs. It often may be seen growing on moist, sheltered and shaded sandstone or limestone formations, generally south-facing in the southern hemisphere, north-facing in the north, or in gorges. It occurs throughout Africa in moist places by streams. On moist sandstone cliffs it grows in full or partial shade, even when unprotected.

Botanists were surprised to find it thriving in the 14th-century underground tunnels of Znojmo, South Moravia. The fern was first found in the tunnels in 2020 and has since spread significantly, thanks to the damp environment and artificial lighting from tourist tours. One theory suggests the fern's spores originated from a houseplant in Znojmo, while another proposes they traveled from a tropical country. Despite its unusual location, the fern is not expected to spread beyond the tunnels or harm local species.