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jan08-offprint-whitehead.pdf

It is well known that some plant leaves, most notably those of the lotus plant, possess super-hydrophobic properties as a selfcleaning feature as a result of the presence of microscopically small surface features.  We have recently noted that the leaves of the arbutus tree exhibit similar properties, and that when the leaf is immersed in water, the air trapped within the nanostructures results in conditions that are favourable for total internal reflection (TIR), causing the leaf to appear extremely reflective from some viewing directions. In this paper, we discuss the basic optical principles behind this natural, unusual and visually interesting manifestation of the phenomenon of TIR.