Cliffs of the Brecon Beacons National Park IPA
Location: Spans 519 square miles of mid-Wales to the north of Merthyr Tydfil.
Grid Reference: SO 009 187
With soaring mountains, ridges and deep valleys carved from sandstone and limestone, the spectacular rocky cliffs of the Brecon Beacons provide sanctuary to an extraordinary number species found nowhere else in the world.
Rising to the unique landmark summits of Pen y Fan and Corn Du, the Brecon Beacons are some of the most spectacular and distinctive upland formations in southern Britain. The majority of the hills take their characteristic colour from Old Red Sandstone laid down some 380 million years ago, while younger grey limestones form their own cliff, gorge and scree landscapes.
Both these rock types have their own special plants, making this an exceptionally rich and diverse area for wildflowers and over 500 species of plants have been found growing here.
On the higher mountains the Old Red Sandstone cliffs provide a home to many arctic-alpine plants, specialists of high altitudes with cold and wet conditions. For some of these distinctly northern species – plants such as purple saxifrage, green spleenwort fern and roseroot - these cliffs are their most southerly spot in Britain. The cliffs are also home to a number of hawkweed species – plants that look like branching dandelions - that are found nowhere else in the world. These include Attenborough’s Hawkweek, named after Sir David Attenborough in 2015, of which just 300 plants are known.
The hawkweeds are particularly important here. Around 100 different ‘microspecies’ have been found - more than anywhere else in Britain - each one unique in their own minute details. Some, like Summit Hawkweed, grow on acidic sandstone rocks but more species are found clinging to limestone rocks at lower altitudes. These include Chalice Hawkweed, Craig y Cilau Hawkweed and perhaps rarest of all Black Mountain Hawkweed, the last survey of which found just 13 plants.
But it’s not just hawkweeds that seem to have gone mad in their evolution. A number of rather beautiful whitebeam trees are also found here and nowhere else in the world. They prefer to grow from the limestone rocks, their roots taking anchorage in the deep clefts and cracks of the cliffs. Half a dozen or so ‘microspecies’ are known, including least whitebeam (around 780 trees known), thin-leaved whitebeam (75 trees known) and Ley’s whitebeam (just 12 trees known).
Where the River Clydach cuts through the limestone, a deep gorge has been carved, a spectacular defile dropping 300 meters (1000 ft) to its confluence with the River Usk. Here, luxuriant beech woodland clothes the steep slopes – the largest area of native beechwood in Wales. Plants to be found here include bird's-nest orchid, soft-leaved sedge, oak fern and yellow bird's-nest. Because of the humidity caused by the spray from the river the banks are good places for lichens, mosses, liverworts and ferns. Hay-scented buckler-fern can be found along with a remarkable Sticta lichen that smells of like a mixture of fish and antiseptic; not surprisingly it’s known as stinky sticta!