A seed of mistletoe (Viscum album) on an apple tree. The seed is encased in a membranous coat (white), and was glued to the bark by the sticky fluid that surrounded it when it was in the berry. This fluid has dried to produce a firm bond between the seed and the bark of the tree. Within a day, a hypocotyl (green, 2mm long) emerged from the right of the seed. Its bulbous tip is in close contact with the bark, and over a period of months, will develop a root (a "sinker") that will penetrate the interior of the branch. V. album is parasitic on a variety of trees. Its seeds are dispersed by birds. Some species eat the berries and spread the seeds in their droppings; others wipe the sticky seed from their beak without ingesting it. The seed here was placed on the branch by hand.