The scientific classification of Oatgrass and Ninebark 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 Ninebark kingdom and all other plants kingdom is Plantaea.
Plant family is the group of plants which have something in common. Oatgrass and Ninebark family is a major factor of Oatgrass and Ninebark 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 Ninebark belongs to the family Rosaceae.
While comparing scientific classification, Oatgrass and Ninebark genus and other classification are also important. Also, when you compare Oatgrass and Ninebark, 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 Physocarpus. Oatgrass tribe is Aveneae and Ninebark tribe is Neillieae. Oatgrass clade is Angiosperms, Commelinids and Monocots and order is Poales whereas Ninebark clade is Angiosperms, Eudicots and Rosids and order is Rosales. Every plant have subfamilies. Oatgrass subfamilies are, Danthonioideae and Ninebark subfamilies are Amygdaloideae. In this way you can compare scientific classification of Oatgrass and Ninebark and other products also.