Subclass Asteridae is a taxonomic rank or a classification hierarchy in the plant kingdom. This subclass belongs to the class Magnoliopsida or dicotyledons, which includes all plants with two seed leaves or cotyledons. The subclass Asteridae comprises many flowering plant families such as the sunflowers, daisy family, mint family, and nightshade family. Synonyms for the subclass Asteridae include Asterids, Sympetalae, and Tubiflorae. These synonyms refer to the same group of plants with shared characteristics such as the presence of petal-like structures or sympetalous corollas. Despite having different names, these synonyms are equally valid in classifying the plants in this subclass.