The scientific classification of Barley and Duckweed 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. Barley and Duckweed kingdom and all other plants kingdom is Plantaea.
Plant family is the group of plants which have something in common. Barley and Duckweed family is a major factor of Barley and Duckweed 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. Barley belongs to the family Poaceae and Duckweed belongs to the family Lemnaceae.
While comparing scientific classification, Barley and Duckweed genus and other classification are also important. Also, when you compare Barley and Duckweed, other factors should also be taken into considerations like order, subfamilies, tribe, clade etc. First plant's genus is Hordeum and other plant's genus is Lemna. Barley tribe is Triticeae and Duckweed tribe is Lemneae. Barley clade is Angiosperms, Commelinids and Monocots and order is Cyperales whereas Duckweed clade is Angiosperms and Monocots and order is Arales. Every plant have subfamilies. Barley subfamilies are, Pooideae and Duckweed subfamilies are Lemnoideae. In this way you can compare scientific classification of Barley and Duckweed and other products also.