Flora in Binntal nature park
A number of different factors come together in Binntal to make it the site of a rich wealth of flora. It has a very varied topography: valleys in all directions, rising from 900 metres above sea level up to mountain peaks at altitudes of 3250 metres; passes from east to west through alternating calcareous and silicate rock. In some places the climate resembles that of Ticino, in others it is more like the dry climate of the Rhone Valley or that of the Simplon region. It is no wonder that many special plants grow here.
The richest flora thrives in the northern part of Binntal on the mostly calcareous Bündner shale, whose brown weathered surface supplies a range of minerals. Especially in early summer, the area is covered in a sea of flowers, including the St Bernard's lily (Anthericum liliago), Turk's cap lily (Lilium martagon), clusters of golden primrose (Androsace vitaliana) and many papilionaceous plant species such as Astragalus and the local rarity, Haller's primrose (Primula helleri). Early in May, the Grengjer tulip (Tulipa grengiolensis) blooms in the rye fields above Grengiols.
In the southern part of Binntal, where the rock is grey, rugged gneiss, alpine roses (Rhododendron) and Swiss willow (Salix helvetica) thrive along the border of forests stocked with larches (Larix) and rare Swiss stone pines (Pinus cembra). Silica-lovers such as the alpine snowbell (Soldanella usilla), lesser masterwort (Astrantia minor), alpine azalea (Loiseleuria procumbens) and incised bellflower (Campanula excisa) are also frequently found.
There is a noticeable wealth of streams and mountain lakes in the gneiss area, which is unusual for the canton of Valais. White tufts of various wool grasses (Eriophorum) adorn the protected moorland landscape of national importance on the Albrun Pass, where the tiny Scottish asphodel (Tofieldia pusilla) and two rare arctic sedges can also be found.
On the southern slopes of the valley, the rocky steppes merge into dry meadows at lower altitudes. Here a variety of wildflowers thrive: round-leaved restharrow (Ononis rotundifolia) with its pink flowers; blue or mountain lettuce (Lactuca perennis), whose flowers only open in the morning; spiked bellflower (Campanula spicata) and milk vetch (Astragalus exscapus); and Valais stock (Matthiola valesiaca) on more rocky ground. In Twingi Gorge, naturally dry habitats are found side-by-side with damp biotopes fed by slope water – giving rise to marvellous plant variety.
Valais stock (Matthiola valesiaca) thrives in calcareous ground, and so chooses rock cracks or the fine rubble of the Bündner shale as its habitat. It is easy to find in Twingi Gorge during the flowering season in June, and can be identified by its rosetted narrow leaves covered in a felt-like layer of grey hairs. But beware: its relative, the yellow-flowering Swiss wallflower, has similar leaves and shares the same habitat. The Valais stock has groups of reddish-violet flowers on a 10–30 cm high stem. Its four crosswise-arranged leaves mark it as a member of the cruciferae family. It is not commonly found in Switzerland, only occurring in the Simplon area and at Pfynwald.
Milk vetch (Astragalus exscapus) is a member of the legume family, to which beans also belong. Its yellow butterfly-like flowers and the beanpods it forms at fruiting time sit deep in the rosette of feathered leaves made up of over 20 hairy leaflets. It is a south-eastern European species, so in Switzerland occurs only in the southern valleys of Valais and is considered a relic of the glacial steppe grasslands. It likes chalky ground and therefore thrives only on Bündner shale. In Binntal it is found on dry meadows, extensively grazed grasslands and in pine forests at mountainous to sub-alpine altitudes. It is easy to find at Binner Gale above Fäld or in Saflischtal.
Haller's primrose (Primula halleri) – named after the famous doctor and botanist Albrecht von Haller, who lived in the 18th century – is related to the bird's eye primrose (Primula farinosa), which can often be found in damp areas. Unlike its smaller cousin, Haller's primrose is a tallish plant reaching up to 30 cm with clusters of pink flowers with a corolla tube 2–3 cm long. It only thrives on chalk-rich Bündner shale in meadows at sub-alpine and alpine altitudes, where the lack of nutrients means there is little competition from other species. In Switzerland its distribution is limited to the southern Alps, and it enjoys full protection as a priority species.
The incised bellflower (Campanula excisa) is a delicate little plant with equally delicate violet bell-shaped flowers indented towards the tips of the petals. It is found nestling in rows in rock cavities or carpeting rocky shale. It flowers at different times depending on the altitude: mid-July around
Lärchultini near Brunnebiel at 1800m asl., and mid-August on the Geisspfad Pass at 2400m asl. It is always found on gneiss rather than Bündner shale, unlike the light-blue earleaf bellflower (Campanula cochleariifolia). It is endemic to the central and western Alps, one of the main concentrations of the plant being here in Binntal.
The Grengjer tulip (Tulipa grengiolensis) has a special story. It belongs to the botanical family Tulipa gesneriana, from which many of our breeding tulips originate. The tulips grow on the Chalberweid near the upper part of Grengiols village, usually blooming yellow, and sometimes red. The variety was discovered and described by the botanist Eduard Thommen around 1945. In the following decades it almost died out, because the winter rye fields on which it grows were successively abandoned. Committed nature lovers founded the Tulip Guild in 1996 and continued the traditional cultivation of rye fields. So the magnificent tulip, which thrives only here, has been preserved to the present day. It is strictly protected.