Definition

Noun: - A taxonomic subclass within the class Magnoliopsida (dicotyledons) comprising flowering plants characterized by having polypetalous (separate petals) or gamopetalous (fused petals) corollas, and often having ovules attached to the walls of the ovary (parietal placentation). This group contains many families, including Ericaceae (heath family), Cruciferae (mustard family, now more commonly Brassicaceae), and Malvaceae (mallow family).

Usage Notes

• This term is used in botanical taxonomy, specifically in certain historical or specialized classification systems for flowering plants (angiosperms). It represents a major grouping of dicot plants.
• In modern phylogenetic classifications (e.g., the APG system), the groups contained within Dilleniidae are often redistributed among other clades, so the term is primarily of historical or reference use.

Examples

Advanced Usage

• Taxonomic Context: The subclass Dilleniidae is part of a hierarchical system: Kingdom Plantae > Division Magnoliophyta (Angiosperms) > Class Magnoliopsida (Dicots) > Subclass Dilleniidae.
• Historical Classification: The concept of Dilleniidae was prominent in the Cronquist system of plant taxonomy. Its circumscription and rank have been revised in newer systems.

Variants and Related Words

• Dilleniid (adj): Pertaining to or characteristic of the subclass Dilleniidae.
  • The dilleniid clade shows a wide variation in floral structure.
• Dilleniales (n): An order of flowering plants sometimes placed within this subclass.

Synonyms

• Dilleniid dicots: A descriptive synonym emphasizing the plants' membership in this subclass of dicotyledons.

Notes on Different Meanings

• This term has a single, specific meaning within the domain of botanical scientific nomenclature. It does not have general English usage outside this technical context.

Noun

1. a group of families of more or less advanced trees and shrubs and herbs having either polypetalous or gamopetalous corollas and often with ovules attached to the walls of the ovary; contains 69 families including Ericaceae and Cruciferae and Malvaceae; sometimes classified as a superorder