A friend was passing a few twigs round in the pub, so I can't photograph it. It grows about person-height, stems are quite slender, leaves are simple, light-green in colour, narrow and about the length of a finger. It has insignificant, tiny flowers. Sounds rather uninteresting, doesn't it ? But I think this friend was hoping that it might do better if moved to a better site, or better soil, but there's not much to be done if he can't give it a name.
I have tried various websites to try to identify this, but they all want more information than I have. Any ideas amongst all you gardeners ?