“…Pollen grains exhibit strong emission of autofluorescent light originating from both their cytosol (intra-cell components) and their complex, multilayered cell wall (e.g., Asbeck, 1955;Driessen et al, 1989;Castro et al, 2010). The natural fluorescence of pollen has been used as a valuable tool for quick and noninvasive in situ analyses of fresh and fossil pollen in diverse scientific fields, such as atmospheric science (e.g., Ronneberger et al, 2002;Mitsumoto et al, 2010;Pan et al, 2011), geology and palynology (e.g., Phillips, 1972;Yeloff and Hunt, 2005), as well as plant physiology and botany (e.g., Roshchina, 2003Roshchina, , 2008Roshchina, , 2012Grienenberger et al, 2009). The following sections characterize the autofluorescence of native pollen using fluorescence microscopy and spectroscopy.…”