sclereider

Sclereider, also known as sclereids in English, are specialized plant cells that form part of the sclerenchyma tissue. They provide mechanical support and protection to various plant organs and contribute to the texture of some fruits and seeds.

Morphology and distribution vary widely. Sclereids can be isodiametric (roughly equal dimensions), elongated, or stellate (star-shaped). They occur in many tissues, including the cortex and pith of stems, leaf margins, seed coats, and the flesh of certain fruits. A common manifestation is the stone cell, a cluster of sclereids that gives a gritty texture to fruits such as pears and guavas. At maturity, sclereids typically die and retain thick, lignified cell walls that resist compression and decay.

Function and significance are primarily mechanical and defensive. The thick lignified walls strengthen tissues against bending and crushing and deter herbivory. In fruits, sclereids help protect developing seeds and contribute to a characteristic texture that can influence dispersal and palatability. Their presence can also affect the processing qualities of crops, such as juice clarity and mouthfeel.

Development and relationship to other sclerenchyma cells: sclereiders originate from sclerenchyma initial cells that differentiate in response to developmental cues and lignification. They differ from sclerenchyma fibers, which are long, tapering cells optimized for tensile strength, whereas sclereids are more varied in shape and often incur more localized mechanical rigidity.