Occurence of the 'Cyperaceae-type' phytolith in dicotyledons

A conical hat-shaped phytolith previously identified as being specific to the Cyperaceae, has been found to occur in species belonging to three dicotyledonous families; the Mimosaceae, Proteaceae and Casuarinaceae, growing in a humid coastal area near Sydney. This phytolith has been used to identify the former presence of sedgeland vegetation. However, its presence in non-sedge vegetation indicates that a greater knowledge of phytolith production in plants is required before they can be used as indicators of past vegetation.