The scientific classification of Hylocereus and Echinocactus 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. Hylocereus and Echinocactus kingdom and all other plants kingdom is Plantaea.
Plant family is the group of plants which have something in common. Hylocereus and Echinocactus family is a major factor of Hylocereus and Echinocactus 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. Hylocereus belongs to the family Cactaceae and Echinocactus belongs to the family Cactaceae.
While comparing scientific classification, Hylocereus and Echinocactus genus and other classification are also important. Also, when you compare Hylocereus and Echinocactus, other factors should also be taken into considerations like order, subfamilies, tribe, clade etc. First plant's genus is Hylocereus and other plant's genus is Echinocactus. Hylocereus tribe is Hylocereeae and Echinocactus tribe is Cacteae. Hylocereus clade is Angiosperms, Core eudicots and Eudicots and order is Caryophyllales whereas Echinocactus clade is Angiosperms, Core eudicots and Eudicots and order is Caryophyllales. Every plant have subfamilies. Hylocereus subfamilies are, Cactoideae and Echinocactus subfamilies are Cactoideae. In this way you can compare scientific classification of Hylocereus and Echinocactus and other products also.