Carex merritt-fernaldii is recommended and seems to be a good fit. Sample collected and can provide more photos.
Same clump as https://www.inaturalist.org/observations/137376492 last year. See link for more info.
ou aquatilis
Forme des touffes bien définies, mais les gaines basales sont peine en échelles.
gaines scabres
dans un fen à Eriophorum