Phylum: Basidiomycota Family: Strophariaceae
Hypholoma elongatum (Pers.) Ricken
Sphagnum Brownie
When it first appears it's deceptively small and bright yellow. Although the common name suggests an associated with Sphagnum, it can occur with other mosses in suitably wet habitats. This habitat is commoner in the north of the country which reflects its distribution. Occasionally found in quite large groups
References:
Noordeloos (2011) Fungi Europaei, 13: Strophariaceae
Breitenbach & Kranzlin (1995) Fungi of Switzerland, Volume 4, Agarics, 2nd Part