The scientific classification of Rhododendron and Pentas 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. Rhododendron and Pentas kingdom and all other plants kingdom is Plantaea.
Plant family is the group of plants which have something in common. Rhododendron and Pentas family is a major factor of Rhododendron and Pentas 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. Rhododendron belongs to the family Ericaceae and Pentas belongs to the family Rubiaceae.
While comparing scientific classification, Rhododendron and Pentas genus and other classification are also important. Also, when you compare Rhododendron and Pentas, other factors should also be taken into considerations like order, subfamilies, tribe, clade etc. First plant's genus is Rhododendron and other plant's genus is Pentas. Rhododendron tribe is Rhodoreae and Pentas tribe is Knoxieae. Rhododendron clade is Angiosperms, Asterids and Eudicots and order is Ericales whereas Pentas clade is Angiosperms, Asterids and Eudicots and order is Gentianales. Every plant have subfamilies. Rhododendron subfamilies are, Ericoideae and Pentas subfamilies are Rubioideae. In this way you can compare scientific classification of Rhododendron and Pentas and other products also.