The scientific classification of Toadflax and Adam's Needle 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. Toadflax and Adam's Needle kingdom and all other plants kingdom is Plantaea.
Plant family is the group of plants which have something in common. Toadflax and Adam's Needle family is a major factor of Toadflax and Adam's Needle 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. Toadflax belongs to the family Scrophulariaceae and Adam's Needle belongs to the family Agavaceae.
While comparing scientific classification, Toadflax and Adam's Needle genus and other classification are also important. Also, when you compare Toadflax and Adam's Needle, other factors should also be taken into considerations like order, subfamilies, tribe, clade etc. First plant's genus is Linaria and other plant's genus is Yucca. Toadflax tribe is Antirrhineae and Adam's Needle tribe is Not Available. Toadflax clade is Angiosperms, Asterids and Eudicots and order is Scrophulariales whereas Adam's Needle clade is Angiosperms and Monocots and order is Liliales. Every plant have subfamilies. Toadflax subfamilies are, Not Available and Adam's Needle subfamilies are Agavoideae. In this way you can compare scientific classification of Toadflax and Adam's Needle and other products also.