Definition

Noun: - A type of placentation in plants: Basal placentation is a botanical term describing the arrangement of ovules within an ovary. Specifically, it occurs when one or a small number of ovules are attached at the very base (the bottom) of a simple ovary or of each carpel in a compound ovary.

Usage

• This term is used in botany and plant morphology to classify and describe the structure of flowers and fruits.
• It is a technical descriptor for a specific reproductive feature in flowering plants (angiosperms).

Examples

Advanced Usage

• Evolutionary Significance: Basal placentation is often considered a simple or ancestral form, frequently associated with plants that produce a single seed per flower (like a sunflower "seed," which is technically a fruit called an achene).
• In Compound Ovaries: In a syncarpous (compound) ovary formed from multiple fused carpels, basal placentation can mean a single ovule is positioned at the base of the entire structure, rather than in each locale.

Variants and Related Words

• Placentation (n): The general term for the arrangement of ovules within the ovary. Other types include , , , and placentation.
• Ovule (n): The structure that develops into a seed after fertilization.
• Ovary (n): The part of the pistil (female reproductive organ) that contains the ovules.

Synonyms

• Basifixed placentation: A less common but technically accurate synonym emphasizing the ovule's attachment point.

Related Terms (Contextual)

• Achene: A simple, dry, one-seeded fruit that does not open at maturity, commonly derived from a flower with basal placentation (e.g., sunflower, buttercup).
• Simple Pistil / Carpel: A structure consisting of a single ovary, style, and stigma, which may exhibit basal placentation.

Noun

1. where one or few ovules develop at the base of a simple or compound ovary