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