Ogwen Lake



One of the defining features of the Cwm Idwal National Nature Reserve is its Arctic-Alpine plants. As the name suggests, these plants are usually found in the cold climates of the Arctic, and the great heights of the Alps. Areas within Cwm Idwal are perfect habitats for some of these plants which have adapted perfectly in these unique surroundings. Some characteristics of Arctic-Alpine species are that they are plants that grow in mats, (or ‘cushions’) which have short flowering seasons. This means that they are safeguarded against the elements of the Cwm, especially during winter.

Purple Saxifrage

One of the first of these plants to flower in Cwm Idwal is the purple saxifrage (Saxifraga oppositifolia). The purple saxifrage usually flowers between February and April, but this can vary, depending on the temperature during the winter season. It very rarely flowers after Easter.

But is the name purple saxifrage suitable for the type we have in Cwm Idwal? The question is raised because we have white and pink flowers occurring on the purple saxifrage here, although there is no genetic difference between those plants with different coloured flowers!

In Norway, the purple saxifrage is called ‘rødsildre’, (red saxifrage), but it is exactly the same plant as we find in Cwm Idwal.

Purple Saxifrige (© SNPA)

Purple Saxifrige (© SNPA)

Roundleaved Sundew (© SNPA)

Roundleaved Sundew (© SNPA)

Round-leaved Sundew

One of Cwm Idwal’s most fascinating plants is the round-leaved sundew, (Drosera rotundifolia). As its name suggests, it can be recognised by its sticky nectar globules, which are used to catch unsuspecting insects! Similarly to butterwort, which can also be spotted at the Cwm, catching and digesting flies supplements the diet of the plant, which lives in nitrogen-deficient bogs.

In addition to providing plenty of insects for the sundews to consume, thanks to the standing water of the lake and bogs, Cwm Idwal also provides the acidic soil needed for the plants to grow. As the slopes of the Cwm are less acidic and have less standing water, you are far less likely to find sundews here than around the lake.

Sundews are said to be medicinal and used to cure anything from warts and corns to asthma and bronchitis – but remember do not harm any plants in the wild. Variants of sundews can be found across the world, except for in Antarctica (I wonder why?). In Western Australia one species of sundews grows up to 10 metres tall! Fortunately for us, the sundews in Cwm Idwal only grow to around 5 inches tall. It’s possible to see sundews in various boggy places within the Cwm, but you will have to look closely for it – and get your feet wet!

Snowdon Lily (© SNPA)

Snowdon Lily (© SNPA)

Snowdon Lily

A species that ignores the rules of Artic-Alpine plants is arguably the most famous of them all, the Snowdon lily (Gagea Serotina). This is the most important plant in Cwm Idwal and one of the most highly regarded. This is because it is the only place in the United Kingdom where it exists. It is found in grassier parts of the northern hemisphere but it is found here on rocks in Snowdonia. Beyond Cwm Idwal the lily is found hundreds of miles away in the Alps, which begs the question, how on earth did it manage to reach Snowdonia in the first place?

One explanation is that Snowdonia is the furthest place it reached during the last Ice Age and that venturing higher into the colder climates of the north was impossible. Another is that the plant did reach further but that it flourished in the shadow of the cliffs through ice movements, while it failed in the Scottish mountains.

Whatever the reason, the difference in the plant’s genetics between our lily and the lily found in the Alps suggests that a division occurred thousands of years ago, therefore the lily is definitely a treasure worth looking after!

Header image - Cwm Idwal (© Crown copyright (2014) Visit Wales)