turgide

Turgide is a term used chiefly in French to denote something swollen or distended. In biology, it relates to turgor, the pressure exerted by water-filled vacuoles against the cell wall. The English-language equivalents are turgid or turgor, but "turgide" appears in some scientific texts, particularly when discussing French-language literature on plant physiology or tissue swelling.

In plants, turgidity arises when cells take up water in their vacuoles by osmosis, generating turgor pressure that keeps cells and tissues firm. The rigid cell wall resists expansion, so pressure supports structure, drives cell elongation during growth, and helps keep leaves erect. When water is lost or the external water potential falls, cells become flaccid, and tissues wilt; severe dehydration can cause plasmolysis.

Turgor changes underlie some plant movements. Guard cells alter their turgor to open or close stomata, regulating gas exchange and water loss. Some species exhibit rapid movements driven by localized turgor shifts in specialized cells, contributing to leaf closure, seed dispersal, or other adaptive responses.

In clinical contexts, tissue turgor denotes the fullness or elasticity of skin and other tissues. Skin turgor is commonly assessed to gauge hydration status: dehydration decreases turgor, while chronic edema can make tissues feel abnormally firm. The term turgidity also appears in descriptions of swelling within organs or cavities due to fluid accumulation.

Related concepts include turgor pressure, osmosis, and plasmolysis.