A very common species nationally but scarcer in Scotland. It is usually associated with Elder Sambucus nigra, but can be found on any deciduous tree or shrub. A saprophyte with a gelatinous structure, hence the common name

References: 
Læssøe & Petersen (2019) Fungi of Temperate Europe, Volume 2
Overall (2017) Fungi: Mushroom & Toadstools of parks, gardens, heaths and woodlands
O'Reilly (2016) Fascinated by Fungi