The 4 metre high dead giant hogweed plants looked attractive silhouetted against the sky.  Each plant can produce up to 80,000 seeds which can remain viable in the soil for 15 years.  But this is bad news as the plant is very invasive and can suppress native vegetation causing harm to the environment. Even worse is that even if it is just brushed against, its sap is toxic and can cause severe burns making skin more sensitive to sunlight.  There were dozens of plants here so it would be a major problem to clear.