The tangle of Mistletoe (Viscum album) on next door's apple tree gets bigger year on year. I'm reminded that the SLBI has a project on iNaturalist to log the locations of Mistletoe across the south of London so I'll add this specimen to their collection.

 Birds eat the berries of V. album but cannot digest the seeds which find a receptive surface on trees with soft bark. There it grows as an obligate hemiparasite i.e. it lives off the host but also photosynthesises.