How does holly attach to oak tree branch and grow without grafting?
That is mistletoe. Holly is a separate bush or tree. From Botanical.com: The well-known Mistletoe is an evergreen parasitic plant, growing on the branches of trees, where it forms pendent bushes, 2 to 5 feet in diameter. It will grow and has been found on almost any deciduous tree, preferring those with soft bark, and being, perhaps, commonest on old Apple trees, though it is frequently found on the Ash, Hawthorn, Lime and other trees. On the Oak, it grows very seldom. It has been found on the Cedar of Lebanon and on the Larch, but very rarely on the Pear tree. When one of the familiar sticky berries of the Mistletoe comes into contact with the bark of a tree – generally through the agency of birds – after a few days it sends forth a thread-like root, flattened at the extremity like the proboscis of a fly. This finally pierces the bark and roots itself firmly in the growing wood, from which it has the power of selecting and appropriating to its own use, such juices as are fitted for it
