The City ordinance provides for a list of prohibited species because providing an exhaustive list of "approved" species would be too voluminous.
Prohibited species means and includes any tree of popular (populus sp.), willow (salix sp.), box elder (acer negundo), silver maple (acer sac-charinum), thorny locust (robina sp.), tree of heaven (ailanthus altissima), catalpa (catalpa ap.), mulberry (morus sp.), Siberian elm(ulmus pumila),birch (betula sp.), and any other species so determined by the Tree Commission. No ornamental trees or conifers, nor any trees with fruit or nuts.