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