This product will affect any plant you spray with it, but it can also kill plants if their roots come into contact with the treated soil. It can kill different types of vegetation and can help prevent the plant from growing again. For people who have garden soils that are heavy clay, Ortho Ground Clear can work for more than a year. If you applied glyphosate (roundup) to the floor, it shouldn't do anything.
If you applied glyphosate to the leaves or possibly parts of the bark, as long as you haven't covered to drain more than 20% to 40% of the tree, you should be fine. Mature trees have thick bark that protects them from many post-emergent foliar herbicides, but choose the herbicide carefully to make sure it doesn't penetrate the roots of the tree. Those containing glyphosate, for example, are usually safe to spray around mature trees. The chemical doesn't leak through the soil, so it shouldn't reach the roots of the tree.
Setoxidim, another herbicide active ingredient, is also considered safe to spray under trees to remove grass and weeds.