libutron:

Collared Parachute - Marasmius rotula
Despite its diminutive size, Marasmius rotula (Marasmiaceae) is one of the most attractive of the many parachute mushrooms and quite the most distinctive. Its preferred habitat is dead deciduous hardwood roots and fallen trunks, branches and twigs, in hedgerows as well as in woodlands. Only occasionally it is found on conifer wood.
The caps of this tiny mushrooms are white or pale cream, and reach up to 1.5 cm across, while the stem is darker brown towards the base, shiny, and up to 7 cm long. 
The Collared Parachute is widespread and common in Britain and Ireland, mainland Europe, and in North America.
Reference: [1]
Photo credit: ©Juan Carlos Poveda Molero | Locality: Irati Forest, Basque Country (2010)

libutron:

Collared Parachute - Marasmius rotula

Despite its diminutive size, Marasmius rotula (Marasmiaceae) is one of the most attractive of the many parachute mushrooms and quite the most distinctive. Its preferred habitat is dead deciduous hardwood roots and fallen trunks, branches and twigs, in hedgerows as well as in woodlands. Only occasionally it is found on conifer wood.

The caps of this tiny mushrooms are white or pale cream, and reach up to 1.5 cm across, while the stem is darker brown towards the base, shiny, and up to 7 cm long. 

The Collared Parachute is widespread and common in Britain and Ireland, mainland Europe, and in North America.

Reference: [1]

Photo credit: ©Juan Carlos Poveda Molero | Locality: Irati Forest, Basque Country (2010)