|Sycamore affected by Tar Spot|
This is caused by a fungus Rhytisma acerinum and affects all sycamores hereabouts. It seems to do little harm to the tree but some horse deaths have been attributed to eating the affected leaves.
Field Maple is undoubtedly native to Britain whereas Sycamore has always been scorned as an alien. However, Ted Green, in an excellent article in British Wildlife (Vol. 16, part 2), casts doubt on this assumption. Pollen in ancient peat deposits is often used to establish the presence of a particular plant but it seems that Sycamore pollen and that of Field Maple are virtually impossible to tell apart, so perhaps it has been here all along. If so we should afford it more respect.
Naturally John Clare got in his six penn'orth:
In massy foliage of a summer green
The splendid Sycamore adorns the spring
Clare's Rural Muse 1835
Clare is buried under a Sycamore at Helpston.