Cystoliths are small, stone-like structures that can form in certain plant cells. They are composed of calcium carbonate and are often found in the cells of plants from the family Moraceae, which includes figs and mulberries. Cystoliths appear as tiny, round or oval-shaped bodies and can vary in size, ranging from a few micrometers to several millimeters.
The formation of cystoliths occurs within specialized cells called lithocysts or cystolith cells. These cells contain numerous vesicles or vacuoles that accumulate calcium carbonate crystals. The crystals gradually grow and aggregate, eventually forming the solid cystolith structures. While the exact function of cystoliths is not fully understood, scientists believe that they may serve as a mechanism for calcium regulation within the plant cells.
Cystoliths are particularly interesting because of their potential ecological significance. Some studies suggest that the presence of cystoliths on leaves can deter herbivory by acting as physical deterrents to feeding insects. For example, the rough texture of cystoliths may make it more difficult for insects to chew through leaves, reducing their ability to feed on the plant. However, further research is still needed to understand the precise role and ecological function of cystoliths in plant defense mechanisms.