About Vandenboschia speciosa (Willd.) G.Kunkel
Vandenboschia speciosa, synonym Trichomanes speciosum, is commonly known as the Killarney fern, a species of fern that is widely distributed across Western Europe. It is most abundant in Ireland, Great Britain, Brittany, Galicia, the Canary Islands, Madeira and the Azores, and can also be found in other locations including France, Spain, Portugal and Italy. This is a relict endemic European species with a disjunct distribution; it had a much wider range before the climate changes that occurred during the Tertiary and Quaternary periods. This fern has an unusual life cycle that includes a perennial gametophyte phase, during which it undergoes active vegetative reproduction. The gametophyte is able to tolerate darker and drier habitats than the sporophyte of the species. In the UK, the sporophyte form of Vandenboschia speciosa occurs at only 16 locations, while the gametophyte form is much more widespread across the country. The species was once recorded on Arran, and was thought to be extinct in Scotland after Victorian plant collectors removed existing populations, but the gametophyte form of the species has since been discovered on Skye. In the UK, Vandenboschia speciosa is classified as vulnerable, and is considered one of the most threatened plant species in Europe. Across the United Kingdom and Ireland, it is mostly found near western coasts, with scattered populations occurring in inland areas. Killarney fern is a medium-sized, long-lived fern that produces delicate, highly divided bipinnate fronds that grow from a creeping rhizome. It is one of only three fern species native to Europe that have translucent leaves, and requires a humid, frost-free environment to grow. In Britain, it is largely restricted to damp, shady, sheltered locations such as ravines, while in Ireland it grows across a wider range of habitats. In Brittany, it can be found growing on the stonework of multiple ancient wells. Vandenboschia speciosa became a protected species in the UK in 1975 under the Conservation of Wild Creatures and Wild Plants Act.
