Anyone know what this is?
Could someone please identify this plant for me? Its taken over a small area which we share with our next door neighbour, and although I've managed to keep it from spreading onto our property,its making rapid progress across his front garden. He's recently rented the house out and I don't know whether the tenants will take any responsibility for the upkeep of the garden, so I want to know whether the growth needs to be suppressed before it does any damage. If so, then I'll contact the landlord and make necessary arrangements. He's a reasonable chap so I don't think he'll refuse.
Thanks in advance.