Dry & above freezing
The sticky bud tree Horse Chestnut - Aesculus hippocastanum
This is the mark left when the old leaf falls on Horse Chestnut - Aesculus hippocastanum seems relevant it looks like a horse shoe to me.
This must be a bird sown shrub as it's on the rucks and not even on show, it was cut to the ground a while ago, did not think it would make a come back but it has, Russian Olive - Elaeagnus angustifolia
Plenty around the valley it must have been planted originally but it crops up all over, Weigela - Weigela florida
Take Care