Giant hogweed is an alien in this country and is a dangerous plant if it comes into contact with humans, especially children. It should be eradicated as soon as it's seen. It's in the same league, though for different reasons, as Japanese knotweed. Sentiment be damned.

Hemlock and hogweed (giant or not) are in the same family 'tis true. But so are carrots, parsnips, angelica, coriander, parsley and chervil, among other comestibles. Potatoes, aubergines, peppers, chillies and tomatoes are in the same family as deadly nightshade, mandrakes, thorn-apples and tobacco.