Thanks all!

Thank you Martin -- I agree with you re "chemlawn" type lawns - we
happily tolerate wild flowers to a certain extent, but the speedwell has
now got to the stage of taking over half the (smallish) lawn -- and we
have it there for the _grass_!

And Yes, Chris, the first place I looked was my own copy of the
brilliant Hessayon book (they are all brilliant, of course).

I take the point about Ioxynil no longer being availlable (like so many
other things -- what a dangerous world we managed to survive! :-/

Thanks for the suggestion of Weedol [Verdone] Lawn treatment (which I
have used in the distant past).

I see your links sell it online Chris - thanks. And the last two,
giving details about speedwell are _very_ instructive: thanks again!)

Cheers chaps
John