Eriophorum vaginatum

Eriophorum vaginatum, Cotton-sedge or Watasuge (scientific name: Eriophorum vaginatum) is an alpine perennial herb in the family Cyperaceae, which is native to the high mountains of the northern hemisphere.
A lot of stems come out from the rhizome and become a big plant, and many of them gather and form a community in the wetland such as Oze.
In early summer, one small pale yellow ear blooms at the end of a long, narrow flower stem.
The stringy floral capsules grow after the flowers and become spherical with white hairs (not flowers but fruit).

Generic name: Eriophorum vaginatum, Scientific name: Eriophorum vaginatum,
Also known as the sparrow's hair spear, Cotton-sedge,
Place of origin: Northern Hemisphere alpine, habitat: north of Honshu to Hokkaido,
environment: marshland, life type: alpine perennial, grass height: 30-60 cm.
Root leaves: pale yellow with grayish-black scales, spike length: 1-2 cm, flowering season: May-June.　
Fruit season (hairs): June to August; scion color (flower-like): white.　
Use: For ornamental purposes, wild vegetables.