Definition

Noun: 1. A secondary division of a leaf: In botany, a "pinnule" is a small leaflet that is itself a subdivision of a larger leaflet (called a pinna) on a compound leaf, especially a bipinnate leaf (a leaf that is divided twice). 2. A small, wing-like part: In zoology, a "pinnule" refers to a small, feather-like or wing-like appendage, often found on certain marine animals like crinoids (sea lilies) or on some feathers.

Usage

The word "pinnule" is a specialized scientific term used primarily in botany and zoology. It describes a specific, small structural part of a larger whole.

Examples

• Botany:
• Zoology:
• Descriptive:

Advanced Usage

• "Bipinnate leaf with pinnules": This phrase describes a leaf that is divided into leaflets (pinnae), which are themselves divided into smaller leaflets (pinnules). This is a common structure in many ferns and some flowering plants like acacias.

Variants and Related Words

• Pinna (noun): The primary leaflet or division of a pinnately compound leaf, which may itself bear pinnules.
• Pinnate (adjective): Describing a leaf where leaflets are arranged on either side of a common axis, like a feather.
• Bipinnate (adjective): Describing a leaf that is pinnately divided, and whose leaflets (pinnae) are themselves pinnately divided into pinnules.

Synonyms

• Leaflet (in a general botanical sense, though less specific than "pinnule").
• Segment (a more general term for a subdivided part).

Different Meanings

1. Botanical Meaning: The smallest ultimate division of a twice-pinnate leaf.
2. Zoological Meaning: A small, lateral, feather-like appendage or process on an animal's structure, such as on the arms of a crinoid or the barbs of a feather.

Noun

1. division of a usually pinnately divided leaf