Life

Bringing ferns to the fore

March 4th, 2016 5:00 PM

By Southern Star Team

A close-up of the curled fronds (known as croziers) of a fern . (Photo: S Franks)

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Taking children on a woodland walk tends to sharpen one’s observational skills. They tend to notice the small things that we grownups might overlook.

Taking children on a woodland walk tends to sharpen one’s observational skills. They constantly ask questions about what they see around them. And, because children are closer to the ground than adults are, they tend to notice the small things that we grownups might overlook.

One such recent tramp on Knockomagh Hill at Lough Hyne with two curious children brought ferns to the fore. With everything else seemingly dead and brown, the graceful fronds of evergreen ferns added a lushness to the undergrowth. I found myself talking about ferns and was reminded of how extraordinary these ubiquitous plants actually are. The children were highly impressed by their beauty and I look forward to showing them the wonderful ‘fiddle-heads’ of other fern species as they emerge over the coming weeks.

Ferns are some of the world’s most primitive plants. They mostly developed at a time before the evolution of flowering plants and before mammals and birds existed. This ancient group dates back some 400 million years and were probably the first true land plants. 

All varieties of fern began life in the water, but adapted to life on land by developing roots to absorb water from the soil. Many ferns grew as large as trees, with enormous fronds that spread out from the top of the trunk to catch the light. In prehistoric times, vast areas of land were covered in tree-fern forests. Large tree-ferns still exist in tropical rain forests today, some as tall as 20m (66ft).

When plants with flowers and seeds developed, about 180 million years ago, they took over the ferns’ dominant position. Ferns now grow most successfully in humid areas, often where there is not much light as they can tolerate shade better than most flowering plants.

However, there are some exceedingly robust members of the fern family that are successful in more challenging environments. The most noticeable of these in Ireland is bracken, which is so common in this country that it is often referred to simply as ‘ferns’.

There are many different species of fern found in Ireland, some rarer than others. Ferns grow especially luxuriantly in woodland but are also found on uplands, in damp hedgerows, growing on old walls and bridges and, of course, the invasive bracken can appear almost everywhere. 

Many of the woodland ferns die back in winter. In spring, the curled fronds – known as croziers – begin to appear. They start off rolled up tightly like coiled rope. As they grow, the tip remains curled over and is the last part to unfurl. The fronds of different species unfurl at various times. The unfolding croziers, also known as ‘fiddle-heads’, add elegance to the waysides. Their delicate beauty is breathtaking and they are truly one of the gentle wonders of spring. 

Instead of producing flowers and seeds to reproduce, ferns produce tiny spores on the underside of their fronds. On each species, these spores form regular patches of different shapes. The shape of the papery material that normally covers the groups of spores is used to identify ferns. 

The hart’s tongue fern, very common in woodland, has leathery leaves more like a doc leaf than a fern and has elongated spores. The male fern, another common species, has spores on the undersides of its fronds in large, circular outgrowths which are covered by flaps. The wind-borne spores germinate if they land in a suitable site.

Bracken also colonises new ground via its wind-borne spores but, once established, it spreads very quickly using its underground network of creeping rhizomes. It is a pernicious invasive plant that out-competes other species and tends to dominate in the areas which it colonises. It can expand by up to 3% annually and is particularly a problem nowadays as there are less grazing animals on the land, especially on uplands. 

Bracken was traditionally controlled by burning but, ironically, it has been found that burning stimulates its spread. The herbicide asulam was also used to control bracken but this is now delisted. I’ve been battling against it spreading into my garden from an adjoining field. The only way I’ve found effective is to dig up the plants that reach into my ground. It’s a tough battle to hold it off.

The fiddle-heads of many fern species are harvested and used as a vegetable. I first heard of this from friends who live in New Brunswick in Canada. There is a festival celebrating them each year in that province and the Canadian village of Tide Head calls itself the ‘fiddle-head capital of the world’. Similar festivals also take place in Vermont and Maine. Fiddle-heads were part of the traditional diet in Northern France, in Asia, Russia and some American Indian tribes as well as the Maori of New Zealand. 

Bracken fiddle-heads are also eaten in East Asia even though it is a poisonous plant. They are considered a delicacy in Japan where roasting them is believed to neutralise the toxins in the plant. Bracken has been found to be carcinogenic to animals when ingested, however, young stems are also commonly used as a vegetable in Japan, China and Korea. There may be a link between this consumption of bracken and higher stomach cancer rates in these countries.

Bracken spores are also a highly dangerous carcinogen. This is particularly important to keep in mind if you decide to cut the plant back. It has been found that its spores can also contaminate local water supplies and, again, it may account for an increase in gastric and oesophageal cancers in areas where there is a lot bracken growth. Bracken can also harbour high numbers of sheep ticks which can cause an incident of Lyme Disease. 

In Victorian Britain, there was a ‘fern craze’ in plant collecting. Known as a Pteridomania (derived from the Latin name for bracken) it spread all over 19th-century Britain and even went as far as Australia. 

The fern cult was originally confined to wealthy garden enthusiasts who could afford to buy the glass jars necessary for the display of  the ferns. However, the removal of the tax on glass fed the boom and, by 1851, the fashion for fern collection was widespread. Ferns featured in the Great Exhibition in London that year and fern hunters travelled the country seeking out rare plants. They cleared whole areas of beautiful rare ferns and some species became extinct in a few locations as a result. 

As the use of real ferns began to decline, ‘virtual’ ferns started to appear in the design of furniture, wallpaper and needlework and it’s an image that we still associate with Victorian Britain today.

In the coming weeks, exquisite fiddle-heads will start to unfurl all around West Cork. Do keep an eye out for them. They don’t have to be confined to a glass jar for their beauty to be admired. Just keep your eyes peeled at child-level and you won’t miss them.

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