The scientific classification of Guava and Petunia 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. Guava and Petunia kingdom and all other plants kingdom is Plantaea.
Plant family is the group of plants which have something in common. Guava and Petunia family is a major factor of Guava and Petunia 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. Guava belongs to the family Myrtaceae and Petunia belongs to the family Solanaceae.
While comparing scientific classification, Guava and Petunia genus and other classification are also important. Also, when you compare Guava and Petunia, other factors should also be taken into considerations like order, subfamilies, tribe, clade etc. First plant's genus is Psidium guajava and other plant's genus is Petunia. Guava tribe is Not Available and Petunia tribe is Not Available. Guava clade is Dicotyledonous and order is Myrtales whereas Petunia clade is Angiosperms, Asterids and Eudicots and order is Solanales. Every plant have subfamilies. Guava subfamilies are, Rosoideae and Petunia subfamilies are Petunioideae. In this way you can compare scientific classification of Guava and Petunia and other products also.