Wood Sorrel ~Oxalix acetosella groing in my raied flower bed brought there by a Bird? Also known as Wood Shamrock and Wood Sour, the leaves of this plant were used to make an ointment by early herbalists. Some people eat these leaves in salads or soups but beware, as large doses may cause oxalate poisoning. Carpeting old, undisturbed woodlands in spring, this pretty downy perennial also grows on moss-covered trees and shady walls and is widespread throughout the country. Each pretty white five-petalled bell-shaped flower (10 - 15 mm) is held solitarily on a stem which comes directly from the roots. The petals are lined with a tracery of pink veins through to the golden centre of the flower. The leaves are trifoliate, each leaflet heart-shaped and these fold up towards late afternoon or in rain as do the fragile flowers. They have a sharp taste of oxalic acid. This flower blooms from April to June, is a native plant and belongs to the family Oxalidaceae.