I found this old sycamore key today lying like some strange deep sea fish on Troy Track on the eastern side of M3. Winter had shredded the blade of the samara revealing the sinews that hold it all together with the muscular, batswing fingers stretching from the seed casing. This casing is slightly chewed as though some creature was, unsuccessfully, after the seed.
There is no fruiting sycamore tree near M3 though two or three seedlings have appeared over the years, so I wondered how far it had samaraed through the air before coming to rest. Despite careful scrutiny I could find no microfungi on it so I have put it in a small plastic box with damp paper to see if anything will incubate.