Influence of Mechanical Damage on Opaline Silica Deposition in Molinia caerulea L.

Abstract

IN our microscopic investigations of opaline silica bodies in the leaves of a large number of British grasses¹, we have found that where leaves were already bruised or torn before being taken from the tiller or culm, the epidermal preparations made from them often showed abnormalities in the degree and pattern of deposition of silica. It was therefore decided to investigate the effects of various kinds of deliberate damage. Molinia caerulea was chosen for preliminary experiments because the silica pattern in this grass had been examined in some detail by us, and opal had been found in a variety of its epidermal cells ranging in size from the intercostal short silica cells to the very large bulliform cells which are silicified erratically near the tips of some of the leaves².