Dryopteris affinis is 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...

 native to western and southern Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

 and southwestern Asia

Asia

Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

.

It is most abundant in areas with high humidity, such as the British Isles

British Isles

The British Isles are a group of islands off the northwest coast of continental Europe that include the islands of Great Britain and Ireland and over six thousand smaller isles. There are two sovereign states located on the islands: the United Kingdom of Great Britain and Northern Ireland and...

 and western France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

; in the Mediterranean region and the Caucasus

Caucasus

The Caucasus, also Caucas or Caucasia , is a geopolitical region at the border of Europe and Asia, and situated between the Black and the Caspian sea...

 it is confined to high altitudes. It commonly grows on moist soils in woodlands.

Description

The Dryopteris affinis fern has dark green frond

Frond

The term frond refers to a large, divided leaf. In both common usage and botanical nomenclature, the leaves of ferns are referred to as fronds and some botanists restrict the term to this group...

s are 60-160 cm long, moderately stiff and hard-textured, bipinnate, with the pinnae opposite on the rachis; the rachis at the base of the frond is densely covered in yellow-brown scales known as ramenta. Each pinna is 8-18 cm long, the pinnules broad rectangular with a slightly serrated margin, and decreasing in size only close to the pinna tip.

Individual fronds live for about 1.5 years and remain attached to the 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...

 after withering. It is closely related to Dryopteris filix-mas

Dryopteris filix-mas

Dryopteris filix-mas is one of the most common ferns of the temperate Northern Hemisphere, occurring throughout much of Europe, Asia, and North America. It favours damp shaded areas and is common in the understory of woodlands, but is also found in shady places on hedge-banks, rocks, and screes...

, distinguished by its usually more robust habit with usually more evergreen fronds, the more densely scaly frond stems, and the more rectangular (less tapered and lobed) pinnae and pinnules.

It is one of the larger European native ferns, with older specimens developing a dense, almost tree fern-like base up to 20-30 cm high and 30-40 cm broad.