Myllylähde’s most significant plant is the endangered greater tussock-sedge, which grows at the northern edge of the spring to a height of nearly one metre and gathers in tussocks of the same width. It is a perennial in the cyperaceae family, and one of the largest and most striking of Finland’s cyperaceae.
Greater tussock-sedge
It is common in Europe as far north as Denmark but in Norway, Sweden and Finland, the species is very rare. It appears around springs in Finland that are located on western and southwestern ridge edges. Most of its sites are located in Hämeenkangas and Pohjankangas in Ikaalinen as well as in Kankaanpää and Karvia. The northernmost locations are located in Isojoki and Kauhajoki. They are found in their greatest numbers in Oripää’s Myllylähde. The species thrives on the shores of large springs due to the increased winter warmth they provide. Its roots will not tolerate freezing, meaning the species is totally dependent on the spring’s water levels remaining roughly the same. It has stems 60 to 150 mm tall and its dark green leaves are tough and sharp.
Greater tussock-sedge can be confused with fibrous tussock-sedge but keen-eyed observers will note the half centimetre wide greyish-green leaves, which are flatter on the fibrous tussock-sedge. In the vicinity of Virttaankangas the greater tussock-sedge’s population is closely monitored every year and changes are followed individual by individual. Both the Alastaro and Oripää mill springs are vital for its reproduction, giving the plant a powerful and competitive edge against other species. It has disappeared from many of its previous sites due to, almost without exception, changes in its natural habitat, such as the building of ditches.
Photo: Juha Kääriä