Japanese Knotweed
The best source of information I know of is Leicester University - http://www2.le.ac.uk/departments/biology/people/bailey/res
Gives useful information on the all-female clone of the species, the less common Giant Knotweed that is hermaphrodite but can't set seed without cross-pollination, and how to tell these two and their hybrid apart.
The photos are largely unlabelled - right click on them and select 'View Image Info' to see the associated text, which will tell you about it.

Giant Hogweed
I've come across a thorough paper on Giant Hogweed, from Countryside Management Publications, including identification, dangers and removal - by both chemical and physical means. It came up in a search and I don't know the URL, so I've filed it here. I trust it will serve your purposes, but as I didn't write it can't vouch for any mishaps using it.

4 comments:

WillC said...
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Pete Hope said...
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Pete Hope said...

That's a nice source of information, unfortunately I would be one of the people more in favour of japanese knotweed eradication. I don't think it's something that can be reliably controlled in the UK without severely altering our eco system.

Pete Hope said...
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