The scientific classification of Oatgrass and Grapefruit 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. Oatgrass and Grapefruit kingdom and all other plants kingdom is Plantaea.
Plant family is the group of plants which have something in common. Oatgrass and Grapefruit family is a major factor of Oatgrass and Grapefruit 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. Oatgrass belongs to the family Poaceae and Grapefruit belongs to the family Rutaceae.
While comparing scientific classification, Oatgrass and Grapefruit genus and other classification are also important. Also, when you compare Oatgrass and Grapefruit, other factors should also be taken into considerations like order, subfamilies, tribe, clade etc. First plant's genus is Danthonia and other plant's genus is Citrus. Oatgrass tribe is Aveneae and Grapefruit tribe is Not Available. Oatgrass clade is Angiosperms, Commelinids and Monocots and order is Poales whereas Grapefruit clade is Dicotyledonous and order is Sapindales. Every plant have subfamilies. Oatgrass subfamilies are, Danthonioideae and Grapefruit subfamilies are Rosoideae. In this way you can compare scientific classification of Oatgrass and Grapefruit and other products also.