Types of Opaline Silica Depositions in the Leaves of British Grasses

Abstract

Eighty of the 150 or so grass species occurring in Britain have been subjected to controlled wet oxidation to facilitate the study of the opaline silica bodies in their silica cells proper, and in cells which are less consistently silicified. The various types of bodies are classified, figured, and described so as to make clear their true three-dimensional shapes, their sizes, relative abundances, and positions relative to other structures in the leaf, noting differences of silica pattern particularly between sheath and blade and between adaxial and abaxial surfaces. The deposition of silica is discussed in relation to suggested functions. Possible causes of differences in the silica pattern sometimes observed between leaves of the same species are considered.