The beautiful world of microscopic colors, as seen by autofluorescence, is clearly demonstrated by a variety of plant structures that secrete or are internally composed of many kinds of natural substrates excited by ultraviolet to blue light that emit in the visible spectrum. This phenomenon serves as the basis of this book, which portrays an array of plant cellular and subcellular structures and their products as seen through various types of fluorescence microscopes (such as the luminescence microscope, confocal laser scanning microscope, and microspectrofluorometer).