Epiphytic

It's odd how we've walked past this oak so many times and not spotted this.  In a high fork  a rhododendron has made its home. It was the sun striking its glossy leaves this morning when much of the oak was in shade that drew my attention. I'm used to seeing bilberry and ferns growing as epiphytes here but not this. It will have been helped by the wet winter.

In more tropical regions rhododendron does use host trees and apparently can be made to grow epiphytically in greenhouses. Here is one essay on the subject.

(posted with some reservations about spelling!)