Clematis

A fast-growing climbing plant producing vine-like stems that quickly harden to become woody. It was found by Frodo and Sam as they travelled through Ithilien, growing across a fire pit piled with broken bones. Even as rapidly as clematis can grow, to begin to cover this scene would probably have taken at least a year.

There are numerous varieties of clematis, differing from one another quite significantly, but Tolkien probably had in mind the species Clematis vitalba, which grows wild in his native Britain. This variety produces small pale greenish flowers during the summer (which turn long and feathery later in the year, giving it the common name of 'Old Man's Beard').