Mesogyne is a botanical term used to describe a specific arrangement of floral organs, particularly the position of the ovary relative to the attachment points of the other floral whorls.
Etymology: The term is derived from Ancient Greek roots: "meso-" (μέσος), meaning "middle," and "-gyne" (γυνή), referring to the female reproductive parts or gynoecium of a flower.
Botanical Context: In a mesogynous flower, the ovary is situated at an intermediate position relative to the attachment points of the sepals, petals, and stamens. This condition typically arises when the floral receptacle forms a cup-shaped structure known as a hypanthium, which surrounds the ovary but is not fully fused to it. The sepals, petals, and stamens are then attached to the rim of this hypanthium, at approximately the same level as the middle of the ovary. Such an ovary is often described as being half-inferior or half-superior.
Relationship to Other Terms:
- Hypogynous: In a hypogynous flower, the ovary is superior, meaning it is positioned entirely above the attachment points of the other floral parts, which are all attached below the base of the ovary.
- Epigynous: In an epigynous flower, the ovary is inferior, meaning it is completely embedded within or fused to the receptacle, and the other floral parts appear to arise from the top of the ovary.
- Perigynous: The term perigynous is broadly used and often considered synonymous with or encompassing the concept of a mesogynous ovary. A perigynous flower also features a hypanthium that surrounds the ovary, with the other floral parts attached to its rim. While "mesogynous" specifically emphasizes the "middle" attachment of the ovary within the hypanthium, "perigynous" generally covers any situation where the floral parts are attached around the ovary on a hypanthium that is not fully fused to it, leading to a "half-superior" or "half-inferior" appearance. In contemporary botanical morphology, "perigynous" is the more commonly employed and comprehensive term for this intermediate floral arrangement.