Dryopteris affinis

Dryopteris affinis
Scientific classification
Kingdom:	Plantae
Division:	Pteridophyta
Class:	Pteridopsida
Order:	Polypodiales
Family:	Dryopteridaceae
Genus:	Dryopteris
Species:	D. affinis
Binomial name
Dryopteris affinis (Lowe) Fraser-Jenk.

Young fronds in spring.

Ramenta on the fern's rachis.

Dryopteris affinis (Scaly Male Fern; syn. D. pseudomas, D. borreri) is fern native to western and southern Europe and southwestern Asia. It is most abundant in areas with high humidity, such as the British Isles and western France; in the Mediterranean region and the Caucasus it is confined to high altitudes. It commonly grows on moist soils in woodlands.

The dark green fronds 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 after withering. It is closely related to Dryopteris filix-mas, 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.

References

'Shuttlecock' form of growth in D. affinis

• Flora Europaea: Dryopteris affinis
• Hyde, H. A., Wade, A. E., & Harrison, S. G. (1978). Welsh Ferns. National Museum of Wales.