Adiantum capillus-veneris

Did You Know?

• One theory suggests the fern's spores in the Znojmo tunnels originated from a houseplant, while another proposes they traveled from a tropical country.
• The frond rachis is black and wiry.

Distribution

This fern is native to humid warm temperate to tropical regions across the globe. It occurs in western and southern Europe, including northern sites in southern Scotland, much of Africa, the Levant, Asia to Japan, Australasia, and the Americas from the southern United States through Mexico and Central America to South America. Two disjunct populations exist in northern North America: Cascade Springs in the Black Hills of South Dakota and Fairmont Hot Springs, British Columbia, where warm microclimates from hot mineral springs allow growth far north of its normal range.

A similar situation occurs at Zvonce spa resort near Pirot in Serbia. The plant grows in temperate to tropical climates with high but not saturated moisture, in well-drained sand, loam, or limestone habitats such as rainforests, shrublands, woodlands, forests, and desert cliff seeps. It often appears on moist, sheltered sandstone or limestone formations, generally south-facing in the southern hemisphere and north-facing in the north, or in gorges.

In Africa it occurs in moist places by streams. On moist sandstone cliffs it grows in full or partial shade. Botanists found it thriving in the 14th-century underground tunnels of Znojmo, South Moravia, first discovered there in 2020, where damp conditions and artificial lighting from tourist tours aided its spread.

Cultivation

Adiantum capillus-veneris is cultivated worldwide for natural landscapes, shade gardens, outdoor containers, and as a houseplant. A winter-hardy hybrid, Adiantum × mairisii, likely involves this species with Adiantum raddianum, Adiantum aethiopicum, or Adiantum cuneatum. As a houseplant, it needs filtered light, high humidity, organic-rich soil, and frequent light watering to keep roots damp but not drenched. It is propagated by dividing clumps with a section of rhizome.

Traditional uses

Native Americans use this plant medicinally. The Mahuna people take it internally for rheumatism. The Navajo people of Kayenta, Arizona apply an infusion as a lotion for bumblebee and centipede stings, and also smoke or ingest it to treat mental illness. In Iranian traditional medicine, a frond infusion is used for jaundice therapy, and the plant is employed for coughs, colds, and to aid kidney function.