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