Date of issue: 22.09.2008 - Value: 10 x 8,00 DKK - Numbers: FO 639-648 - Stamp size:  29,5 x 45,0 mm - Sheet size: 165,5 x 118,0 mm - Desing: Edward Fuglø - Printing method: Offset - Printer:  LM-Group, Canada - Postal use: Inland letters up to 50 g.
 

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Ferns are flowerless plants
Ferns belong to the group of plants that are known as flowerless. There are about 20,000 different kinds of fern and this group is the biggest after the group of flowering plants, which numbers 250,000 different kinds. Most ferns are found in the tropics and thrive best in damp surroundings.

Ferns are considered primitive plants that are closely related to primeval plants. They have neither flowers nor seeds and reproduce with the help of spores which, in some kinds, accumulate in spore clusters on the underside of fronds and are protected by a shield that opens when the spores have matured so that they can spread. In other kinds, the spores are attached to the edges of the fronds that are curled inwards as long as the spores have not matured.

Some kinds have two kinds of frond: a sterile frond and a fertile frond. The fertile fronds of some ferns may have a completely different appearance than the sterile fronds. A fern can produce millions of spores, but few of them become new plants.

Spores have different shapes. They can be kidney-shaped or round, of different colours – light or dark – and these differences are often used to identify them.

Fronds also differ. They may be subdivided into one, two, or more leaflets, or not subdivided at all. An important characteristic of ferns is that they resemble a fiddlehead before they are fully grown due to their special growth conditions.

The Faroese name for fern is 'trøllakampar', which means 'troll's beard' and not 'troll's comb' as is often heard.

Ferns were very common in the Faroes before the 'landnam' period. This can be seen from seed corn surveys. All plant growth in the Faroes depends on sheep grazing and this is the way it has been since people first came to the islands. The sheep they brought with them immediately began to gorge themselves on the lush vegetation that was found on the islands at that time. This vegetation rapidly disappeared and was replaced by the 'close-cropped' appearance we are familiar with today.

But the sheep could not eat everything, so it is possible to see the remains of the original vegetation in ravines and on ledges that they could not reach. Here, the vegetation is luxuriant and varied and surveys have shown that the plants have lived in these locations for a long time – precisely because they were out of the reach of sheep and people.

Many kinds of fern can be found in steep terrain. Most prominent are the big male ferns (dryopteris filix-mas) and the almost equally big female fern (athyrium filix-femina). Seed corn surveys have shown that the occurrence of ferns was reduced dramatically after people settled in the Faeroes with their domestic animals.

There are fifteen kinds of fern in the Faroes. Most of them grow in clefts in rocks where there is moisture and shade, but they can also be found in stony and steep terrain and ravines. The most common Faroese fern is the 'fragile fern' (cystopteris fragilis). 'Black spleenwort' (asplenium adiantum-nigrum) and 'maidenhair spleenwort' (asplenium trichomanes), on the other hand, are very rare and can be found in only one place. A new fern was discovered in 2007 at Norðuroyggjar. This was a 'hart's tongue fern' (asplenium scolopendrium), which is also rare in the Nordic countries.

Anna Maria Fosaa