The scientific classification of Onion and Peony 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. Onion and Peony kingdom and all other plants kingdom is Plantaea.
Plant family is the group of plants which have something in common. Onion and Peony family is a major factor of Onion and Peony 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. Onion belongs to the family Liliaceae and Peony belongs to the family Paeoniaceae.
While comparing scientific classification, Onion and Peony genus and other classification are also important. Also, when you compare Onion and Peony, other factors should also be taken into considerations like order, subfamilies, tribe, clade etc. First plant's genus is Allium and other plant's genus is Paeonia. Onion tribe is Allieae and Peony tribe is Not Available. Onion clade is Angiosperms and Monocots and order is Asparagales whereas Peony clade is Angiosperms, Core eudicots and Eudicots and order is Not Available. Every plant have subfamilies. Onion subfamilies are, Allioideae and Peony subfamilies are Not Available. In this way you can compare scientific classification of Onion and Peony and other products also.