Adiantum raddianum takes its species name from Italian botanist Giuseppe Raddi, who collected widely in Brazil in the early nineteenth century. Native to the tropical Americas and West Indies, this fern grows in the damp shade of forest floors and rock crevices where moisture is constant and light is gentle. It reaches 1 to 2 feet high and wide in a graceful, arching habit, its decompound fronds carrying triangular, lobed pinnules on the signature wiry black stipes of the genus. Deciduous in cultivation, it retreats if conditions become too harsh, but recovers quickly when conditions improve.

The critical requirement is moisture: the roots should not be allowed to dry out, and the surrounding air should carry some humidity. Terrariums are an excellent environment, as are sheltered rock gardens set in wet pebbles. As a houseplant it performs best in bathrooms or kitchens where ambient humidity is higher than in the typical living room. It tolerates partial shade but loses vigor in deep shade and dislikes direct sun. The Florida Fern Caterpillar is the main pest concern for outdoor specimens in warm climates. Zones 9 to 10.