Unusual tree

Unlikely to be this one (my money is on Cassini's Mediterranean medlar) but at least it proves Grape trees do exist.  http://ia.wikipedia.org/wiki/File:Coccoloba_uvifera.jpg Ding, ding, seconds out.

Probably a Crabapple.

If the fruit smells like and reminds you of apples, it could be any member of the Malus or Rosaceae species and there are quite a few. Here you have some information: http://en.wikipedia.org/wiki/Malus

It might be worth checking if its a walnut tree, they look like small apples when growing and can smell of citrus.

...walnuts have only just dropped their last year's fruit.

Walnuts long gone at this time of year...but then I have no idea what it is either!, could add you to Marche Gardener Penny on FB.

No, it's not a walnut. I know those and the fruit are ripe and have mostly fallen here. Not crab apples as they don't grow in clusters like grapes. These grew just like very large grapes. Most odd.

Try looking at Malus sikkimensis - I found various snaps of this (on google) which seem promising, but haven't looked further to see if maturation time, leaves, etc. are correct. I tend to go along with Gala that if it smells like an apple it probably bears a close relationship to an apple!

Thanks Fillide but that's not it either as the fruit grow like grapes in bunches. I've never seen anything like it. Wish I'd taken a photo now!

Could it be a "Wampee" tree?

I wouldn't say the leaves were like birch, and it isn't likely to smell like an apple, but the fruiting time and grape like bunches sound okay, and it would just about survive (hardy to about minus 6degC). It's evergreen, and there is a b+w illustration on ths page. http://www.hort.purdue.edu/newcrop/morton/wampee.html#Origin%20and%20Distribution

Alright clever clogs - perhaps it aint a Wampee - perhaps it's a grape tree.   How the Hell d'ya upload photo's here?

What about this one? http://en.wikipedia.org/wiki/File:Malus_sikkimensis0.jpg It is still a "Malus" variety.

Aint that a Crabapple under any other name?

Further to my previous post, Malus sikkimensis is the Chinese Wild Apple. Here is some more information: http://www.fruitipedia.com/sikkim_wild_apple%20Malus%20sikkimensis.htm

You have (in the blue corner) advocates of malus sikkinensis (which at least has the potential to smell like an apple) or in the red corner, the acknowledgley unlikely wampee. I know (from previous forum experience) that Penny is a nicely 'serious' person, and I'm sure she is more than willing to hike up into her mountain and take a reaaly high res snap of the fruit upon which she has stumbled. Seriously - we need a pic! I was thining of suggesting underripe arbutos unedo - or (do not slap me down here) the possibility that the fuit belonged to a neighbouring tree and was hanging about looking as if it 'belonged'! 

Come on, Penny, go hiking up the mountain. I second Fillide's suggestion. Take a photo.... if you can find the tree....

Off you go then Penny, you will never find it today though, its a gorillas in the mist sort of day. Medlar fruit anyone?....at least it looks and smells like an apple. (though nothing like a birch tree). 

Could it be an azerole.  Here is a link http://en.wikipedia.org/wiki/Crataegus_azarolus   http://www.pfaf.org/user/plant.aspx?LatinName=Crataegus+azarolus

OK - not sure if we're getting closer or further away to be honest. The fruit grows just like a wampee but they were not translucent and were a bright apple green colour. The wampee fruit looked like some kind of gooseberry. The birch-like leaves might be a red-herring as the tree was mingled with lots of others. The tree is a hour's drive away but next time I am over that way I wll definitely take a photo if it's still in fruit! Driving me mad :-)

Did they look like this?  The clusters of Wampee fruit can be much bigger and closer together - just like a bunch of grapes - than this picture shows, but you can at least see the colour and relative size of the fruit. http://phronesisaical.blogspot.com/2011/02/wampee.html If not, then I guess that mountain hike is on the cards..