Lac du Crachet

«Clapier» is the term used in the southern Alps to describe a heap or cairn of stones. They are evidence of past farming activity. In fact, stone clearing was a way of cleaning the fields and making them usable. This made it easier to work the soil and gain more land for cultivation. At the time, everything was done by hand.

Not for nothing is this perennial plant, with its robust, hollow stem that can grow to more than a metre, commonly known as the great gentian. It has several tiers of yellow flowers at the tip, grouped together and supported by a pair of broad, opposite leaves. Its robust, fleshy root, buried deep in the ground, is a godsend for lovers of home-made spirits and aperitifs. Many mountain folk believe that "the higher the Gentians are in summer, the more snow there will be in winter..."

The Latin term Plantago means «plant that acts», an allusion to the medicinal properties attributed to it by the Romans. They claimed that when applied to wounds or insect bites the crushed leaves had a healing effect. Although not very tasty, this plant is edible cooked, or even raw. It grows in grasslands and meadows. It has a characteristic flowering stem emerging from a cluster of thick leaves with broad veins running up from the base.

A large black and white butterfly, its wings punctuated by red,the Apollo is symbolic of our mountains. It can commonly be seen from May to September in the grasslands and among the screes. It remains common in the Alps, but is much rarer elsewhere. It appears to move to a higher altitude and/or bring its flight period forward in order to compensate for the current climate warming. It moves higher to avoid high temperatures and could therefore lose suitable environments favourable to its development. It is a protected species and catching it is prohibited.

The black-veined white is the biggest of the Pieridae in France, a family of butterflies which are usually pale in colour. It is distinctive for its black veins against a white background, on both sides of the wings. The female looks slightly yellowish. This species used to be common everywhere. In spite of its decline, it is present in large number in the mountains and can be spotted from June to August.

In Les Écrins, this little grey or brown southern lizard can be confused with the viviparous lizard. It can be distinguished from it by a black spot at the leg joint. It is found at altitudes of up to 2,500 metres, in various natural environments that are well exposed to the sun, but also in man-made areas. The common wall lizard currently appears to be expanding northward. The railway lines have supported further colonisation thanks to development works which constitute favourable habitats!

The wings in the male of this little butterfly has dark grey upper sides, rather bluish at the base, while the female is brown. It is seen most commonly at high altitude in July and August, in meadows and grassy areas. The Arctic blue is a species native to northern regions (Scandinavia, Greenland, Siberia, North America). In more temperate regions, it only lives in the mountains.

Pastoralism is a widespread livestock husbandry technique. The aim is to drive the flocks to «natural» areas where they can feed. This method helps to keep the land clear, which favours a particular biodiversity. Good management of an alpine pasture should allow the resource to be «exploited»,but without compromising its regeneration. The advantages are many, not only for the environment but also for the well-being of the animals and farmers.

A rodent of medium size, the marmot is the iconic symbol of high-altitude grasslands. It has a solid, almost cylindrical body, short ears, and stubby legs with strong claws. At the slightest sign of danger, it utters a high-pitched whistle. A true hibernator, it is only active above ground from April to October. Marmots live in family groups. Their many social interactions - grooming, playing and also fighting and biting - guarantee group cohesion and respect for the hierarchy.

This orchid is a herbaceous perennial plant. It is also hermaphrodite, that is to say, each plant is male and female. Grouped in threes to sixes, its flowers are very spread out and generally spotted with purplish marks on the upper side. Appearing in June to July, it flowers in the forms of a simple dense spike holding 10 to 25 purplish-red flowers. Its pollination is entomogamous, that is to say, it is pollinated by insects. It prefers damp places in full sunlight. It can be seen at altitudes of up to 2,500 metres.

The Lac du Crachet is a glacial lake, like most of the mountain lakes. It is an oligotrophic mountain lake, that is to say, it is a stretch of clear, deep, nutrient-poor water containing very little organic matter and with a high level of dissolved oxygen. It dries out completely during periods of intense drought. The Torrent du Crachet mountain stream flows from it into the little valley which shares its name, before flowing into the Crévoux mountain stream.