Medlar Mespilus germanica isn't a native tree in Britain and it doesn't seem to produce many viable seeds here, but it has been naturalised in a few hedges in southern counties. It's also quite widely planted in botanic gardens, on account of its large, attractive white flowers in spring, vibrant yellow autumn foliage and these curious fruits. Medlars need to be softened by frosts and a period of natural decay after they ripen - a process known as 'bletting' - before they are ready to eat. They have a slightly resinous flavour and are a bit of an acquired taste but I quite like them. There's a tree loaded with the fruits that I pass every day and as soon as the frost has done its work I'll make some medlar jelly - unless someone gets to the tree before me. I've tried to germinate the seeds from the fruits, with a complete lack of success.
The fruits of common lime Tilia x europaea are unmistakeable, being attached to a leaf like bract that slows their fall and allows them to spin to earth when they're released from the tree. It's not as aerodynamically efficient as the winged seeds of sycamores or ash, judging from the concentration of lime seeds that end up very close to the parent tree. Many of the seeds are sterile.
Folklore has it that a heavy holly berry crop is a sign of a hard winter to come. What it really indicates is that back in late May, when the trees were flowering, conditions were good for pollinating insects to carry pollen between the separate male and female trees. Trees with no berries at this time of year are most likely males, which can't produce berries, or females that were too far from a male to be pollinated. Some cultivated hollies carry flowers that are hermaphrodite and always produce berries. There's also a rather attractive yellow-berried form.
Stately elms that once graced the landscape are now history, thanks to the ravages of Dutch elm disease, but shrubby hedgerow elm is still common enough. Its clusters of crimson flowers produce masses of discus-shaped winged seeds - but they are all sterile. Hedgerow elms were all propagated from cuttings, so they were all genetically identical and all equally susceptible to the lethal fungus - only a few mature trees have survived.
For more on tree identification click here