Photographs: Co. Cork

Japanese Knotweed Reynoutria japonica (Fallopia japonica) Glúineach bhiorach Family: Polygonaceae Flowering: August-October. Perennial. Introduced. Garden escape. Spikes of white flowers. Reddish zig-zag stems. Broad leaves, oval-triangular, pointed. Spreads rapidly by rhizomes, forms large thickets. Height: To 2m Roadsides, wasteland, streamsides. Widespread and very invasive introduction, difficult to eradicate. Originally introduced as garden plant, now designated as a significant invasive plant in Ireland Similar: Giant Knotweed, Reynoutria sachalinensis

Japanese Knotweed, Reynoutria japonica (Fallopia japonica), Glúineach bhiorach