Information on Buckthorn

Common Name: Buckthorn
Scientific Name: Rhamnus cathartica
Irish Name: Paide bréan
Family Group: Rhamnaceae
Distribution: View Map (Courtesy of the BSBI)
Flowering Period

Click for list of all flowering by month
Buckthorn could sometimes be confused with:

Buckthorn, Alder,

This is a deciduous shrub which is not too commonly found throughout Ireland. It has small green star-shaped flowers (4–5 mm) which have four widely-spaced pointed-petals. These flowers, which bloom from May to June, are borne in small clusters, the male and female being separate. Later in the year, the plant bears shiny black berries. The long, almost-opposite, oval leaves are finely toothed and clearly veined. Often quite thorny, this shrub can reach 6 m but grows quite low also as it does in the Burren. It is a native plant and it belongs to the Rhamnaceae family.  

I first saw this shrub at Lough Gealáin in the Burren in 2010 and am grateful to Dr Stephen Ward, joint BSBI Vice-county Recorder for Co Clare for his identification. 

If you are satisfied you have correctly identified this plant, please submit your sighting to the National Biodiversity Data Centre

Buckthorn is the food-plant of the Brimstone butterfly. Formerly known as Purging Buckthorn, a rather strong and hazardous purgative was made using the bark and fruit.