I have the weed growing in my garden, I'm told be a neighbour that it's one
of these "superweeds" whose roots will eventually lift my patio and make my
house fall over. Any ideas what it is, and how to kill it? I've tried
spraying it with weedkiller, I've drilled down the main stem and filled it
with weedkiller but it still comes back and I don't have enough room between
patio and fence to dig it out or burn it.

The second problem is a fungus that's growing on a wooden bench, any tips
how to get rid of this would also be appreciated.

Thanks!

weed: http://i29.tinypic.com/68tvug.jpg

fungus: http://i28.tinypic.com/24vobyp.jpg