The Atlantic woodlands
The steep and rocky west coast of Scotland, riven with deep ravines and regularly buffeted by moisture-laden winds straight off the Atlantic, is an ideal habitat for bryophytes. The overwhelming impression in these magical places is of a thick carpet of green festooning rocks and trees. This carpet is usually a mixture of mosses and liverworts, but it is the ‘oceanic’ liverworts that are of particular interest here, as a number of them have a very limited distribution in Europe and some are globally rare. Two of the most characteristic species, typical of the best oceanic woodlands, are Spotty featherwort Plagiochila punctata and Prickly featherwort Plagiochila spinulosa, which often grow together with Wilson’s filmy fern Hymenophyllum wilsonii on rocks and trees. Both of these species, although locally abundant in the west of Scotland, have a very restricted distribution elsewhere, being limited to the extreme western seaboard of Europe and the Atlantic islands such as the Azores and Madiera.
Also occurring with these two species in the best woodland is Deceptive featherwort Adelanthus decipiens, which reaches its northern world limit in Scotland. Outside the British Isles it occurs only in north-west France and Spain.
Where there are ravines cutting through the woodland, the bryophyte flora becomes even richer, although you have to ‘think small’ to find the best plants. The speciality here is a community of tiny liverworts growing on the steep faces of large rocks, and occasionally on trees, close to the river or burn, where humidity remains constantly high and frost is rare. Some of these species such as Toothed pouncewort Drepanolejeunea hamatifolia have a very limited distribution worldwide, while others such as Hutchin’s hollywort Jubula hutchinsiae var. hutchinsiae and Brown scalewort Radula aquilegia are European endemics with their world headquarters in the west of Britain.