Silicon, the second most abundant element in soils, is readily absorbed by plants and can be found in appreciable concentrations in their tissues, ranging from a fraction of 1% to several percent. Despite its prominence as a mineral constituent, silicon is not typically considered an essential nutrient for terrestrial higher plants, except for members of the Equisetaceae. This review highlights the significant roles silicon plays in plant biology, including its effects on mineral nutrition, growth, and resistance to abiotic and biotic stresses. Silicon is crucial for the absorption and translocation of various nutrients, contributes to the mechanical strength of cell walls, and helps mitigate the adverse effects of heavy metals and salinity. The omission of silicon from nutrient solutions in experimental plant biology may lead to distorted results, as it is an important environmental factor for plants. The review also discusses the potential taxonomic, anatomical, archaeological, and medical implications of silicon's presence in plants.Silicon, the second most abundant element in soils, is readily absorbed by plants and can be found in appreciable concentrations in their tissues, ranging from a fraction of 1% to several percent. Despite its prominence as a mineral constituent, silicon is not typically considered an essential nutrient for terrestrial higher plants, except for members of the Equisetaceae. This review highlights the significant roles silicon plays in plant biology, including its effects on mineral nutrition, growth, and resistance to abiotic and biotic stresses. Silicon is crucial for the absorption and translocation of various nutrients, contributes to the mechanical strength of cell walls, and helps mitigate the adverse effects of heavy metals and salinity. The omission of silicon from nutrient solutions in experimental plant biology may lead to distorted results, as it is an important environmental factor for plants. The review also discusses the potential taxonomic, anatomical, archaeological, and medical implications of silicon's presence in plants.