ANOTHER LIFE:IT IS HARD to think of a modern social obsession that could compare with the fern craze of the early Victorian - mainly British - middle class. Part of a newly born, mostly aesthetic, fascination with natural history, it made the shade-tolerant fronds of pteridophytes a must-have embellishment for the elegant drawing-room. Conservatories became lush and humid ferneries; the new "Ward case" (a sort of closed pocket-greenhouse on legs) kept wild ferns alive in the coal-fire fug at the heart of big cities.
The new railways brought distant countrysides within reach and albums of pressed ferns became holiday memorabilia. If you couldn't climb about and dig your own to take back, there were cartloads of ferns coming in from afar, not least in Killarney, already a tourist town. Among them were heaps of a specially beautiful plant, with finely-cut, translucent leaves, many still wet from their niches in shadowy, spray-filled clefts of the mountains.
The Killarney fern, Trichomanes speciosum, now among the rarest in Europe, was actually first recorded in Ireland at Co Wicklow's Powerscourt waterfall around 1800. Collectors extinguished it there and at many other places, but it still survives at some 30 sites, one with at least 2,390 fronds (the precise number quivers with botanical concern). The colonies are mostly in Kerry and Cork, but small ones have been found in half a dozen other counties.
Most locations are kept secret by local botanists, which must suggest certain difficulties in the "all-Ireland species action plan" for the conservation of the fern, published online this month by the National Parks and Wildlife Service (NPWS). Informing landowners of the plant's presence on their land, and county councils of the need to protect it, not to mention "raising awareness" of the plant's importance - all among the plan's objectives - could carry a miserable risk. Although the species is strictly protected legally, North and South, and by no fewer than 17 Special Areas of Conservation orders, greedy collection is still a potential problem. But trampling, grazing and woodland clearance are perhaps, in the long term, more hazardous still.
I shall probably never see Trichomanes speciosum, but I have admired the feeling and precision of field notes by the British fern authority, Christopher Page. He describes large patches of the plant "arching from the surface of steep rock faces on short wiry stipes, then drooping gracefully down, forming overlapping curtains of similarly inclined blades. In such situations, the translucent texture and fine dissection of each blade allows filtered light to pass to other fronds . . . while the pointed pinnule tips steadily drip with slowly percolating water running over the delicate and pellucid, rigid frond surfaces, which nod spasmodically with each drip released . . . " Such affinity for water and humidity must have doomed most amateur attempts to grow the fern at home. Indeed, the occasional mistaking of its dried fronds for a seaweed in herbarium collections recalls the ancient place of ferns in the evolution of land plants. Even in Ireland's "recent" history, the plant could be very ancient. Its North Atlantic range spreads down western coasts to Cape Verde, off Africa, and it is not beyond possibility that it survived the last ice age in its present refuges in Kerry and Cork. Even today's plants may spring from colonies dating back several centuries. Their fronds can take months to unfurl, and last for years.
For the botanist, perhaps the greatest fascination of Trichomanes is in how it reproduces and survives. In a life cycle typical of ferns, it has two stages or generations. One is the full, fronded plant - the sporophyte - that sheds spores rather than seeds. The other is the gametophyte that grows from the spore but needs specially moist conditions in which to fertilise itself and produce the fern.
The Killarney fern is odd, in that its gametophytes can lead independent lives far from a sporophyte colony and reproduce all by themselves - a development not discovered in Ireland until the 1990s. The ferns, too, can spread independently, by creeping rhizomes. In fact, Ireland's colonies rarely produce spores, so it's as if the two-generation lifestyle has broken down. There are gametophytes in far more places than the fern itself, and in Galway and Mayo, for example, they can be found in mossy clumps in dark, damp places 100km from the nearest clump of fronds.
Two botanists - Naomi Kingston of the NPWS and Cathy Hayes of Trinity - have been researching the implications for conservation: just how many Special Protection Areas (SPAs) for Trichomanes speciosum will there need to be? Meanwhile, you could ask to see the fern in all its beauty at the National Botanic Gardens, who have had it growing for 150 years. Only over the past year or so, however, have its botanists managed to grow its spores into gametophytes. Perhaps, if the gardens eventually offered Killarney fern for sale, collectors might feel they could leave it alone in the wild.
"The Killarney fern, now among the rarest in Europe, was actually first recorded in Ireland at Co Wicklow's Powerscourt waterfall around 1800