Quick facts

Common name(s): hard fern, deer fern, herringbone fern, northern fern, snake fern

Scientific name: Blechnum spicant

Family: Blechnaceae

Origin: native

In leaf: year-round

Habitat: woodland, heathland, moorland, mountain grassland, hillsides

Hard fern is a hardy evergreen fern. It can grow 45–60cm tall and 45–90cm wide, and remains green and fertile for most of the year.

Leaves/fronds: the fronds are single pinnate, which means that the individual leaflets the frond is divided into, known as the pinnae, aren’t further divided. They grow directly opposite each other on the stem which gives them a herringbone appearance. They taper in at both the tip and the bottom of the stem.

Hard fern is dimorphic, which means it has two types of frond – sterile and fertile. The sterile foliage has long, flat, leathery, dark green fronds with slightly wavy edges. They arch outwards, almost parallel to the ground, and can grow up to 30cm. The fertile fronds are longer, narrower and upright. They grow in the centre of the plant with their leaflets spaced further apart from each other, and the outer edges rolled inwards on the undersides.

Rhizome: scaly

Sori/spores: the sori (the reproductive structures which produce the spores) are on the underside of the fronds. They are round and are orange-brown when mature. The spores ripen from June to August and are released when the sori burst open, and the spores are spread by wind.

Not to be confused with: other ferns, especially those which are singularly pinnate, such as common polypody (Polypodium vulgare).

Where to find hard fern

Hard fern is widespread throughout the UK and the rest of Europe. It is also recorded in North Africa, Asia, Russia and Japan and parts of North America.

It prefers moist, acidic, humus-rich conditions in woodland sites; and also grows on heaths, moors, mountain grassland, rocks and open hillsides to 1200 metres, in hedgerows and along watercourses. 

Trees woods and wildlife

A sign of ancient woodland

Hard fern is an ancient-woodland-indicator plant. If you spot it while you're out exploring, it could be a sign you're standing in a rare and special habitat.

Learn more about ancient woodland

Credit: Derek Croucher / Alamy Stock Photo

Value to wildlife

Red deer feed on hard fern in winter when there are few green plants available. No insects specifically feed on hard fern, though the broom moth and some sawflies will eat the fronds. The rust fungus Milesina blechni is specific to hard fern, and occurs on the over-wintered fronds.

Did you know?

The name spicant comes from the Latin word ‘spico’ which is translated as ‘furnished with spikes’.

Uses of hard fern

The plant has been used as an emergency food when all else fails. The rhizome would be cooked as a source of starch and the young, tender stems would be peeled and the centre part eaten.

The leaves were traditionally chewed as a hunger suppressant and to alleviate thirst, particularly by the Hesquiaht people of the Pacific Northwest. This was especially useful when hunting and travelling. It was also noticed that deer rubbed their antler stubs on hard fern after they had shed their antlers, which inspired its use to treat sores and other skin problems.

The leaves were traditionally used as a treatment for stomach problems, lung disorders and even cancer; while the rhizome was made into a concentrated liquor used to treat diarrhoea.

Threats and conservation

The hard fern is common and widespread. It's not currently considered under threat.