achene

/ə'ki:ni/

Thân thiện

A single dandelion seed head releases its achenes into the breeze.

Definition

Noun: - A small, dry, indehiscent fruit: A type of simple, one-seeded fruit where the seed is distinct from the fruit wall (pericarp). The fruit does not split open (indehiscent) at maturity to release the seed.

Usage

• The term "achene" is used in botany to describe a specific fruit structure. It is a technical term.
• It is typically used as a countable noun (e.g., "an achene," "several achenes").

Examples

Advanced Usage

• Botanical Classification: Achenes are a common fruit type found in many plant families, including Asteraceae (e.g., sunflowers, dandelions) and Ranunculaceae (e.g., buttercups).
• Key Characteristics: The defining feature is that the seed coat is not fused to the thin, dry pericarp. This distinguishes it from similar fruits like grains (caryopses), where the seed coat is fused to the fruit wall.

Variants and Related Words

• Achenial (adj): Of or relating to an achene.
  • The achenial fruit is well-adapted for dispersal by animals.
• Cypsela (n): A specific type of achene found in the Asteraceae family, derived from an inferior ovary. Often used interchangeably with "achene" in a broad sense.
  • The fruit of a sunflower is technically a cypsela.

Synonyms

• Nutlet: A small nut, often used informally for some small, hard, one-seeded fruits similar to achenes, though botanical definitions can vary.

Antonyms

• Dehiscent fruit: A fruit that splits open at maturity to release seeds (e.g., a pea pod, a capsule).
• Fleshy fruit: A fruit with a soft, juicy pericarp at maturity (e.g., a berry, a drupe).

Học thuật

Noun

1. small dry indehiscent fruit with the seed distinct from the fruit wall