Electron microprobe analysis was used to examine relative amounts of selected accessory elements (Ca, Mg, K, Na, P, Mn, and Fe) associated with silicon in silica cells in leaf epidermal cells ofCyperus alternifolius. In the leaf epidermal cells, silicon is localised in significant quantities in silica cells and in a few long epidermal cells. Silicon could not be detected in the stomatal apparatuses. The accumulation of significant amounts of silicon in the silica cell appears to retard the accumulation of K and to enhance the accumulation of Ca, Mg, Mn, Fe, and P. Sodium was detected in very small traces in the silica cells. The possible functional significance of the altered deposition patterns for these elements inCyperus is discussed.