The scientific classification of Watermelon and Iris 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. Watermelon and Iris kingdom and all other plants kingdom is Plantaea.
Plant family is the group of plants which have something in common. Watermelon and Iris family is a major factor of Watermelon and Iris 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. Watermelon belongs to the family Cucurbitaceae and Iris belongs to the family Iridaceae.
While comparing scientific classification, Watermelon and Iris genus and other classification are also important. Also, when you compare Watermelon and Iris, other factors should also be taken into considerations like order, subfamilies, tribe, clade etc. First plant's genus is Citrullus and other plant's genus is Iris. Watermelon tribe is and Iris tribe is Irideae. Watermelon clade is Angiosperms, Eudicots and Rosids and order is Cucurbitales whereas Iris clade is Angiosperms and Monocots and order is Asparagales. Every plant have subfamilies. Watermelon subfamilies are, and Iris subfamilies are Iridoideae. In this way you can compare scientific classification of Watermelon and Iris and other products also.