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