Janet Tweedy wrote:
Idea please? NOT the horrid bright yellow-leaved gledista, it must look
like a tree, i.e. be green.

what about Field Maple (Acer campestre). I've got one, on heavy clay.
OK, it's common as muck but it grows nearly a metre a year if the soil
is wet enough and looks fantastic when the leaves change colour. Then
it drops millions of the damn things, good if you like collecting for
leaf mould.

Dappled shade? Yes, if you thin it out a bit. It can be coppiced, if
you are a tree butcher, but left alone it forms a nice hemisphecial
crown, or a bit more open if you get in there with a bow saw.

Home to lots and lots of insects. OK, we had a red spider mite
infestation when it was tiny, lasted about 3 years, but it shook them
off and nothing else suffered.