The fens on the lower slopes of the dale sides tend to be flushed with water arising from limestone or more acidic rocks. The resulting limestone flushes can be very species-rich especially when not heavily grazed by sheep – supporting bird’s-eye primrose, devil’s-bit scabious, butterwort, marsh valerian and flat sedge. There is also potential for the fungi fen puffball in this habitat in the Dales. The more acidic flushes hold a reduced variety of herbs but still a wide array of sedges, rushes and invertebrates. Very occasionally the rare marsh saxifrage occurs in this habitat. Acidic flushes also support breeding birds like snipe and are important feeding areas for other birds.
To encourage cross pollination, Primula species produce two different types of flower. Some plants have flowers with short styles and anthers positioned at the mouth of the flower whilst the other plants have flowers with long styles and anthers, located further down inside the flower. In addition to the different positions of styles and anthers, Primula species also have different types of pollen and stigma.
There are 425 species of Primula worldwide, many of which grow in China. The birds-eye primrose species has pink or lilac flowers and dusty looking leaves. Within the United Kingdom, it is found almost exclusively on damp grassy, stony or peaty ground on limestone in the northern Pennines and the Lake District. As a result, the plant is often known as the ‘Yorkshire primrose’.
In the Yorkshire Dales National Park, the bird’s-eye primrose can be seen flowering in May and June in base-rich flush habitats in the south National Park. Good examples of its preferred habitats are towards the peaks of Ingleborough and in Malhamdale where it often grows alongside the common butterwort.
Grass of Parnassus
This native plant of the Saxifrage family has heart-shaped leaves and ivory white chalice-shaped flowers with distinctive glistening yellow stamens. It is the only species of the genus Parnassia native to the UK.
It is found in marshes, damp grasslands and dune-slack habitats (hence the latin name palustris meaning boggy or marshy). It is not a common plant but is found locally in much of Britain and Ireland. However it is rarely found in most of South Wales and Southern England.
Grass-of-Parnassus is a late summer gem in the Yorkshire Dales. According to the Botanical Society for the British Isles (BSBI) it is present throughout the Yorkshire Dales National Park. However, it likes alkaline soil conditions and so is more frequently seen in the SW of the park on the Limestone Country such as on the Malham Tarn National Nature Reserve and Upper Wharfedale managed by the National Trust.
With its evocative name, Devil’s-bit scabious is a member of the teasel family and can be found on the damp grasslands, wood margins and road verges of the Yorkshire Dales National Park.
The ‘scabious’ part of the name is due to the plant’s properties which could allegedly cure leprosy or scabies. And the ‘devil’s bit’ is in reference to the abrupt ending of the root which appears to have been bitten off. Another name for the plant is ‘blue-caps’ because of its pretty pale lilac-blue flowers that appear from June until early autumn.
Devil’s-bit scabious is one of the three species of scabious which occur in the Yorkshire Dales National Park. The other two species – Small scabious (Scabiosa columbaria) and Field scabious (Knautia arvensis) can be distinguished from devil’s-bit by their divided basal leaves.
Butterworts, so called because they are alleged to coagulate milk, are insectivorous perennials with solitary flowers and a basal rosette of leaves covered in slime. The common butterwort is one of two native butterwort species in the British Isles and has purple flowers and yellow-green leaves resembling a starfish. The common butterwort the leaf margins curl over insects and glands on the leaf secrete enzymes which digest the soft parts of their prey.
The common butterwort is locally common in Britain and Ireland. It is more often found in the North and West of Britain and is absent from most of Central and Southern England. In the Yorkshire Dales National Park it is commonly seen growing alongside bird’s-eye primrose and grass-of-Parnassus on good limestone flush habitats. For example, on the Malham Tarn National Nature Reserve in the Limestone Country in the South West of the Park.