Asplenium ceterach is a fern

Fern

A fern is any one of a group of about 12,000 species of plants belonging to the botanical group known as Pteridophyta. Unlike mosses, they have xylem and phloem . They have stems, leaves, and roots like other vascular plants...

 species commonly known as Rustyback. It is characterised by a short rhizome

Rhizome

In botany and dendrology, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...

 which gives rise to several green fronds that have a pinnated lamina with trichome

Trichome

Trichomes are fine outgrowths or appendages on plants and certain protists. These are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae.- Algal trichomes :...

s on the abaxial (lower) surface, but not the adaxial (upper) one. These trichomes (hairs) are orange-brown in colour, hence the name "rustyback". The petiole is shorter than the corpus of the leaf.

This species is found in Western and Central Europe, including the Mediterranean region. It is associated with fissures in carbonate rocks and also grows on the mortar of stone and brick walls.

This fern species has been used medicinally as a diuretic

Diuretic

A diuretic provides a means of forced diuresis which elevates the rate of urination. There are several categories of diuretics. All diuretics increase the excretion of water from bodies, although each class does so in a distinct way.- Medical uses :...

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Growing Conditions

It likes growing in rocky walls, especially in alkaline ones. Can be found growing up to 2700 metres above the sea level, although it prefers mountainous locations, where it is usually found growing in sunny rocky walls.

Unlike many others, this fern likes growing in full sun, and requires little, if any, humidity.