Definition

Noun: - The protective outer layer or integument of a seed, especially in flowering plants. It is the outermost part of the seed coat, derived from the outer integument of the ovule.

Usage

The term "episperm" is a specific botanical term. It is used to describe the physical structure of a seed in a scientific or academic context. - The episperm is crucial for protecting the embryo from mechanical damage and desiccation. - When studying seed morphology, one examines features of the episperm.

Examples

• Under the microscope, the thick episperm of the date seed was clearly visible.
• The hardness of the episperm can affect seed germination rates.
• Botanists noted differences in the episperm texture between the two species.

Advanced Usage

• In some seeds, the episperm becomes fused with the fruit wall, making it difficult to distinguish.
• The term is often used in contrast with "endosperm," which is the inner, nutritive tissue of the seed.

Variants and Related Words

• Testa: This is a more common synonym for the seed coat, often used interchangeably with episperm, though "testa" can sometimes refer to the entire seed coat complex.
• Seed coat: The general, non-technical term for the protective outer layer of a seed.
• Integument: The general term for a protective layer, especially in botany for the ovule and seed coverings.

Synonyms

• Testa
• Seed coat
• Outer integument (of a seed)

Antonyms

• Endosperm (the inner nutritive tissue, not a protective outer layer).
• Embryo (the developing plant within the seed, which the episperm protects).

Noun

1. protective outer layer of seeds of flowering plants