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Ferns and Horsetails

FERNS AND HORSETAILS

Ferns are flowerless plants with feathery or leafy fronds. They reproduce by spores released from the undersides of the fronds.

HART'S TONGUE FERN

Asplenium scolopendrium

Hart's tongue has a preference for damp shaded locations. In Hainault Forest it is found growing on the bank of Olgits's ditch and the old reservoir area on Hog Hill.

The fern resembles the shape of a deer's tongue. A hart is an adult male deer, hence the name. The long glossy-green leaves known as fronds have pointed curly tips.

The plant grows up to 60cm tall and is seen throughout the year. The strap-like fronds 30-100mm in length unroll as they develop. The spore producing sori are arranged in oblique lines on each side of the midrib on the underside of the fronds. The spores are orange-brown.

Before Foxburrows Barn was restored as part of the Hainault Restoration Project in 2022 this fern was a common sight on the damp walls.

BRACKEN

Pteridium aquilinum

A common fern in the forest in the wooded areas and open spaces within the woodland especially under Silver birches. It is invasive and difficult to control and is a serious pest in Britain. It occurs worldwide. The whole plant dies down in autumn with the first frosts and the new vegetative frond unfurls in the spring. The large triangular compound frond which can be up to 2 metres in height is described as tripinnate, meaning that it has divided three times. Part of the background has been removed to highlight the single frond. Rarely produces spores in woodland.

MALE FERN

Dryopteris filix-mas

Male fern unfurling.

Common throughout the forest especially in the damper, shadier parts of the woodland. Fronds ascend and arch, giving the plant a shuttlecock appearance. They can be up to a metre in length and are widest in the middle. The frond is divided into 20-40 pinnae. Each pinna (right) is broad at the base and tapers to a point. Each pinna is divided into pinnules. On fertile fronds the pinnules have 2 rows of kidney shaped sori on the underside. These contain the spores.

BROAD BUCKLER-FERN

Dryopteris dilatata

Common in the forest especially in the shadier parts on the slopes behind the farm. Fronds can be up to 1 metre in length although usually 30-40cm. One third of the frond is stalk. Fronds arch and are more or less triangular in shape, deep green colour and tripinnate (i.e. divided three times). The first division produces a pinna. These are further divided into pinnules, and then pinnulets. On the stalk are scales and those particularly near the base are pale brown and have a dark brown line running through them which distinguishes the plant from other Buckler ferns.

Scales

Magnificent Broad buckler-fern on Dog Kennel Hill.

Mophead Galls appear as knots on top of Broad Buckler ferns which are caused by a fly.

SOFT SHIELD FERN

Polystichum setiferum

Uncommon in the forest. The fronds are 30-40cm. and bright green. They are bi-pinnate, and widest in the middle. About one-quarter of the frond is stalk covered in fine, light brown scales. The pinna are divided into pinnules which have a small stalk and are mitten shape. The prominent "thumb" running more or less parallel with the midrib of the pinna

Part of the underside of a fertile pinna showing the mitten-like pinnules with two rows of rounded sori.

POLYPODY FERNS

Polypodium

Western polypody fern Polypodium interjectum in Hainault Forest and very rare species in Essex. Thanks to Dr Kenneth Adams for a positive identification viewing spore structure under the microscope.