Sir Thomas Overbury included the line, ‘All the carnall beauty of my wife is but skin-deep’ in his poem ‘A Wife’, written in 1613. From it we have the proverb ‘Beauty is only skin deep’. Bark is the layer covering the stems and roots of woody plants; the visible bark on trees called the rhytidome. Human skin is the outer covering of the body; it is the largest organ of the system that protects the body from external damage. Bark, skin – in both cases the outermost layer is a veneer of dead cells.
Photo: Botanic Garden, Cambridge, August 2017