More tradition than tree, don't waste your time looking up this genus. Clootie, in old Scottish vernacular, means a strip of rag or cloth. It was a Celtic tradition to tie rag ribbons to a Clootie tree branch as a healing ritual. Such trees, usually growing besides Clootie wells, were places of pilgrimage in Scotland and Ireland. It was explained to me by a Whidbey artist with his own Clootie tree, that people made a wish, tied their ribbon, and as the rag grew tattered in the wind and weather the wish was released to the Universe to act upon. In modern times the wish was made to a saint, in the past to a goddess or nature spirit.
The lovely story was enough to inspire this Clootie tree in my Langley garden, in the hopes visitors will pick a rag ribbon, make a wish, tie it to the tree. It only took this phrase in the Wikipedia entry on Clootie trees "Additional votive offerings were hung on the branches...." to inspire a few added embellishments....
