The scientific classification of Rhubarb and Sunflower 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. Rhubarb and Sunflower kingdom and all other plants kingdom is Plantaea.
Plant family is the group of plants which have something in common. Rhubarb and Sunflower family is a major factor of Rhubarb and Sunflower 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. Rhubarb belongs to the family Polygonaceae and Sunflower belongs to the family Asteraceae.
While comparing scientific classification, Rhubarb and Sunflower genus and other classification are also important. Also, when you compare Rhubarb and Sunflower, other factors should also be taken into considerations like order, subfamilies, tribe, clade etc. First plant's genus is Rheum and other plant's genus is Heilanthus. Rhubarb tribe is Not Available and Sunflower tribe is Heliantheae. Rhubarb clade is Angiosperms, Core eudicots and Eudicots and order is Caryophyllales whereas Sunflower clade is Not Available and order is Asterales. Every plant have subfamilies. Rhubarb subfamilies are, Not Available and Sunflower subfamilies are Helianthodeae. In this way you can compare scientific classification of Rhubarb and Sunflower and other products also.