The scientific classification of Old Man Cactus and Collard Greens 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. Old Man Cactus and Collard Greens kingdom and all other plants kingdom is Plantaea.
Plant family is the group of plants which have something in common. Old Man Cactus and Collard Greens family is a major factor of Old Man Cactus and Collard Greens 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. Old Man Cactus belongs to the family Cactaceae and Collard Greens belongs to the family Brassicaceae.
While comparing scientific classification, Old Man Cactus and Collard Greens genus and other classification are also important. Also, when you compare Old Man Cactus and Collard Greens, other factors should also be taken into considerations like order, subfamilies, tribe, clade etc. First plant's genus is Cephalocereus and other plant's genus is Brassica. Old Man Cactus tribe is Pachycereeae and Collard Greens tribe is Brassiceae. Old Man Cactus clade is Angiosperms, Core eudicots and Eudicots and order is Caryophyllales whereas Collard Greens clade is Not Available and order is Brassicales. Every plant have subfamilies. Old Man Cactus subfamilies are, Cactoideae and Collard Greens subfamilies are Not Available. In this way you can compare scientific classification of Old Man Cactus and Collard Greens and other products also.