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Square-stalked Willowherb Epilobium tetragonum Family: Onagraceae Flowering July-August. Perennial. Introduced. Pale pink flowers with 4 notched petals and entire, club-shaped stigma, calyx tube without glandular hairs. The fruit capsule is long, 6.5 to 10cm. Narrow leaves are strap-like, toothed and almost stalkless and the stems have 4 conspicuous raised ridges. Over-wintering basal leaf rosettes. Scattered distribution on damp waste and cultivated ground, roadsides, by streams and in woods Similar: Pale Willowherb and pale forms of American Willowherb

Square-stalked Willowherb, Epilobium tetragonum