A scanning proton microprobe study of macrohairs from the lemma of the grass <i>Phalaris canariensis</i> L

Abstract Proton-induced X-ray emission combined with a scanning proton microprobe has been used to investigate the distribution of inorganic elements in silicifying macrohairs from the lemma of the grass Phalaris canariensis L. Results, presented in the form of X-ray spectra and two-dimensional elemental maps, showed that the inorganic elements Si, K, P, S and Cl were spatially organized within the macrohairs during the different stages of silicification. Much lower quantities of all elements except silicon were found in the mature macrohairs. It is suggested that these changes in the inorganic content of the macrohairs are related to a silicification process that is associated with cellular activity.