Bryophytes

Bryophytes are surely the Cinderellas of the plant world; they are there in the background but they are unseen. Look under the next patch of Nettles and you will very likely find masses of the big moss Brachythecium rutabulum. There will be more moss plants than nettles and quite possibly the moss will have the greater biomass: but to many people, there are just nettles. And yet bryophytes are often of ecological importance as colonisers. The sand dunes of the Sefton and Flyde coast are justly famous for their flowering plants; but how does vegetation get established in shifting, wind-blown sand? Look in loose sand around the Marram grass and you will find clumps of the beautiful gold-green moss Tartula ruraliformis binding the sand and providing a foothold for bigger plants.

The moist slacks on the landward side of the Sefton dunes are the home to a number of rare bryophytes of National and even European importance. Several of these are species of Bryum, superficially resembling Bryum capillare which is common on many wall tops and conspicuous for its large drooping capsules, but it is difficult to distinguish the different species. However, there is no mistaking our prize liverworts of the dune slacks, Petalophyllum ralfsii; the problem is finding it! Although spectacular it is tiny, and best searched for on hands and knees. This species and some of the Bryum species are protected by law and must not be interfered with in any way.

The Trough of Bowland and the South and West Pennines provide a range of bryophyte habitats and a remarkable diversity of species; this has been quantified in recent surveys by counting species numbers in 2km square areas (tetrads). Among the richest areas are deep rocky cloughs with fast-flowing streams, especially those with woodland. Many tetrads in Bowland have well over 100 species and around Leck Beck there are a couple of tetrads with well over 200 species. Even the Pennines fringes adjoining industrial areas are remarkably rich, with around 100 species in the tetrads containing Lead Mines Clough (east of Chorley) and Gorpley Clough near Todmorden. In such habitats one finds some spectacular large mosses such as Dicranum majus and Ryytidiadelphus loreus and the streams will have big green cushions of liverwort Scapania undulata and perhaps Nardia compressa which is nationally rather scarce but quite frequent in Lancashire.

The moorland around these rocky cloughs is generally less species-rich but there is still much of interest. In particular, the springs and flushes have beautiful and colourful green Philonotis fontana (often with spherical capsules above the slick-like shoots) mingle with patches of bright green Dicranella palustris, and it is likely there will be Bryum pseudotriquetrum, darkish green touched with red. If there is wet rock, perhaps around a little waterfall, it may be draped with coppery-brown Sphagnum denticulatum. Many bryophytes are, like litchens, sensitive to air pollution. Any naturalist who learns to recognise these interesting mosses can make useful records of their recolonisation of our country.