Regarding my request for help ID-ing my unknown, cordate-leaved, spurred foliage tree:

Thank you so much for all the suggestions - who would have thought it would be this difficult!

Replying in order:

Nick - when I said "exotics" I should have said "ornamentals", sorry. I think it was self-set, rather than a bought-and-planted ornamental, which is why I suspected it would turn out to be something embarassingly common. It's a young tree, I only noticed it for the first time last year, so I can't comment on the older bark - it's currently plain smooth light grey. It's growing in the oil-tank's unlovely hidden corner, on a steep bank, right hard up against a brick wall - clearly not a place where you would choose to plant a tree of any sort.

Emery - Davidia involucrata: golly, it does look rather like that, doesn't it? But I'm pretty sure it isn't, as no-one would plant one of those beautiful trees round the back of the oil tank... and as Stewart pointed out, Davidia doesn't seem to have leaves on spurs, whereas this tree does.

Stewart: definitely not Tilia, so no, your document didn't help, but it was very interesting so thank you for the link to it. ("always something to learn...")

Sacha - definitely not Mulberry, black or white, I'm familiar with both of those. There is a Mulberry (nigra) in the same garden but I have to say, I've never found a single seedling from it, and trust me, I have looked! Also, the Mulberry leaves are generally just slightly shiny, and these ones are quite matte - mind you, it's a young tree, so they could differ from the adult foliage, I suppose?

Phil: thank you for the suggestion, but no, not Populus - the petioles are round, not flattened.

David - I'll take responsibility for part of your "ouch!", as I should have waited until I could upload the photos before starting this discussion: sorry.

Kay - I'm glad to hear you say that you've never seen Mulberry set seed, either: I have two trees that I visit regularly, and I always look for seedlings, just in case... I suspect they have to go through a bird first, and are therefore likely to end up some distance away. I've repeatedly tried propogating via truncheons, as all the books suggest, with total failure. Although I brought home a bunch of smallish pruned branches earlier this year, left them sitting in a pot of water and forgot about them for, ooh, 6 weeks or so. Found them a fortnight ago, they were sprouting leaves! So I potted up 8 of them, and so far 2 have definitely died but the others are looking so-so. Not one of the traditional rooting methods, but if it works.....

So, to return to the mystery tree: bizarrely, Davidia involucrata is looking the best so far. I'll be going back for another look hopefully later this week, so I shall try to look for more clues. If there's anything that I should be looking at in particular, do please let me know.

Thank you all very much indeed for the suggestions so far.

Rachel