Hi, I have seen the type of bark that you are talking about. I think my grandma had the same thing, You may be able to get it by speaking with your local florist, while they may not have it in stock they may be able to order some in. If your local florist does not have it, try checking out a nursery in your area, again they should be able to order it or something simular in for you.
I would not use any bark that you would find from a
tree in the wild, as it will more then likely be a home to many insects and diseases.
Mike
