Study of outer bark of Birch (Betula verrucosa) and Cork Oak (Quercus suber) by scanning electron microscopy

The outer bark of corkoak and birch constitutes a particularly suitable starting material for the study of suberin, the cell wall substance that imparts specific properties to the cork cell. In investigations of birch and oak suberin made by the author in the fifties, great interest was attached to the publications of Ribas on the chemistry of cork. The present article contains a brief survey of the differences between, and the similarities in, the outer bark of these two wood species, demonstrable on the basis of the investigations mentioned. This comparison, concerned with the chemical properties, is supplemented by a number of scanning electron micrographs of the cork tissue of the two species.