The scientific classification of Tree-of-Heaven and Firethorn includes the entire classification chart that includes kingdom, family, clade, tribe etc. A kingdom is the second highest taxonomic rank. A taxonomic rank is the level that a living organisms are placed in hierarchical level of arrangement of life forms. All the living organisms are divided into kingdoms. Plant kingdom is a main classification of living organisms that include all plants. There are six kingdoms which are: Plantae, Animalia, Fungi, Protista, Aschaea/Archaeabacteria and Bacteria Eubacteria. Tree-of-Heaven and Firethorn kingdom and all other plants kingdom is Plantaea.
Plant family is the group of plants which have something in common. Tree-of-Heaven and Firethorn family is a major factor of Tree-of-Heaven and Firethorn Scientific Classification. Plant family helps you narrow the search of your plants. It also gives you idea about, how the plant looks, how the seed will be like etc. These two plant families can be different or same. Tree-of-Heaven belongs to the family Simaroubaceae and Firethorn belongs to the family Rosaceae.
While comparing scientific classification, Tree-of-Heaven and Firethorn genus and other classification are also important. Also, when you compare Tree-of-Heaven and Firethorn, other factors should also be taken into considerations like order, subfamilies, tribe, clade etc. First plant's genus is Ailanthus and other plant's genus is Pyracantha. Tree-of-Heaven tribe is Not Available and Firethorn tribe is Maleae. Tree-of-Heaven clade is Angiosperms, Eudicots and Rosids and order is Sapindales whereas Firethorn clade is Angiosperms, Eudicots and Rosids and order is Rosales. Every plant have subfamilies. Tree-of-Heaven subfamilies are, Not Available and Firethorn subfamilies are Amygdaloideae. In this way you can compare scientific classification of Tree-of-Heaven and Firethorn and other products also.