The name derives from the Greek “dry” adíantos, used by Theophrastus in the Historia plantarum, probably to mean that the water flows on the fronds whose lamina does not absorb it (hence its need for constant atmospheric humidity). The Adiantum is widespread all over the world, especially in tropical and sub-tropical countries, but some are spontaneous even in very cold regions. They are rhizomatous ferns, with pinnate, simple or compound leaves that extend into many species in the characteristic fan shape. There are more than 100 species with many varieties.
Rustic cultivated species:
A. capillus veneris, the real maidenhair, spontaneous in almost all of Europe, has fronds that can reach 50 cm in length; exists in several varieties including Adiantum imbricatum, more compact, from the leaves deeply lobed and almost imbricate. This species, particularly useful in caves, natural or artificial, rocky edges of fountains in shady places, crevasses in shaded and constantly humid walls, grows practically on any substrate and often on a minimum amount of soil or mud also accumulated by chance. Adiantum pedatum, native of North America, natural, with long leaves and thick leaves, joined to the rachis by a very short petiole. Also of this species there are different varieties.
Non-rusticated cultivated species:
all these species require a minimum winter temperature of about 15 ° C, but always combined with a very strong humidity; they are therefore suitable for greenhouses where this moisture can be maintained and it is almost impossible to keep them in the apartment. Adiantum caudatum, a small species with simple feathered, gray-green, hanging fronds, which can be grown in vases or suspended baskets and whose greatest particularity consists in being “viviparous”, that is, in forming on the tip of the old fronds small tufts of leaves that emit root and can be used for multiplication. A. cuneatum, originally from Brazil, the most commonly used species for commercial purposes as a pot plant. There are a large number of varieties and cultivars, including dissectum, elegans, gracillimum. In general, given the impossibility of a description, it can be said that the more the variety is made up of light, feathery, septenate fronds, etc., the more difficult it is to cultivate it; A. tenerum, another widely commercial species, with many varieties, which has the particularity of having young pink or bronzed vegetations until the frond is developed. More resistant than the cuneatum, the Adiantum tenerum scutum roseum; more delicate, but splendid, the Adiantum tenerum farleyense.
the ferns reproduce by spores that should be seeded on an absolutely sterile substratum always kept humid at a temperature of about 18 ° C. The resulting seedlings should be repotted as soon as possible in small tufts of 3 or 5 seedlings, in terrines with fibrous ground and moist fertilizer but with good drainage, until they have grown enough to put them in separate jars. However, if this method with all the relevant precautions is used for commercial production, the simplest way to multiply a few plants is to divide the tufts, taking care that each new plant has at least one piece of rhizome. The soil must be composed of fibrous earth, peat, and earth of leaves with a little sand and some fragments of softwood charcoal. The moisture content of the mixture must be continuous but not excessive to prevent rotting and atmospheric humidity always ensured.