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GIANT HOGWEED Heracleum mantegazzianum (Apiaceae) Height to 4m. Huge and impressive biennial or perennial whose size alone makes it unmistakable. Stems are hollow, ridged and purple-spotted. Whole plant causes blisters if touched in sunlight. Favours damp ground and often found beside rivers. FLOWERS are white and borne in umbels up to 50cm across (Jun-Jul). FRUITS are flattened and narrowly oval. LEAVES are pinnate and up to 1m long. STATUS-Introduced and naturalised locally.