Ivy

A tough, trailing plant with numerous three-lobed leaves, ivy grows in tendrils to climb over other plants, but can also grow on other surfaces such as stone, or across the ground. It is attested to have been growing on the trees that formed the western gates of Mirkwood, and also the rocks that formed the shores of Anduin above the Emyn Muil.

It was clearly far more widespread than the Vales of Anduin, and we can be sure it was known as far to the west as the Shire, because it appears in names used by the Shire-hobbits. Not only was it used there as a personal name (as seen in 'Ivy Goodenough'), but also in The Ivy Bush, the name of an inn on the Bywater Road near Hobbiton.