Found mainly on damp, peaty soil but also across the limestone pavement of the Burren, Alder Buckthorn is a shrub or small deciduous tree which can reach to 5 metres high. It bears small green-white flowers (3mm across) which have 5 triangular petals and 5 sepals, 5 stamens and 1 style. They are borne in dense clusters in the axils of the upper leaves. The distinctive leaves are oval, alternate and untoothed. They are shiny green and have 7 pairs of lateral veins. The flowers bloom in May and June, followed by round berries (6-10mm across) which start as green, becoming red and then black. This is a native species which is not widespread, occuring mainly in the north, midlands and Counties Galway and Clare. It belongs to the Buckthorn or Rhamnaceae family.
I first identified this species in 2017 beside Loch Gealain in the Burren when I also photographed it.
If you are satisfied you have correctly identified this plant, please submit your sighting to the National Biodiversity Data Centre