Tree of Heaven (Ailanthus altissima (P. Mill.) Swingle) Division - Magnoliaphyta Class - Magnoliopsida Subclass - Rosidae Order - Sapindales Family - Simaroubaceae Genus - Ailanthus Tree of Heaven resembles sumac, but can be differentiated by the leaf-shape, which features dentation at the bottom near the stem, but goes straight further up the leaf. This is one of the most destructive of city weeds. It is highly invasive and tears apart concrete. Weeds Taxonomic List List by Scientific Name List by Common Name