Classified as a ‘Potentially Invasive’ introduction into Ireland, so far this species has not gained too much ground, only establishing itself in a few spots. It is a low-growing plant – only reaching about 20cm high – with really tiny, white flowers in June and July. These flowers are borne in spherical heads, solitarily on erect stalks which rise from creeping stems. There are 3-4 pairs of glossy, toothed, pinnate leaves, ending in a terminal leaflet. The plant cleverly spreads itself by means of red, spiny seeds which are in round heads and grip onto animals’ fur and our shoes and socks. Pirri-pirri-bur tends to grow on dry, sandy soil and heathland. This is a perennial plant which belongs to the Rosaceae or Rose family.
I first saw and photographed this plant close to Inistioge in Co Kilkenny in 2013.
If you are satisfied you have correctly identified this plant, please submit your sighting to the National Biodiversity Data Centre