Table 1.

Overview over the data sets and histological parameters extracted from the Raman imaging data.

Plant Organ	Number of Maps	Number of Different Cells a	Number of Complete Cells b	Extracted Cell Wall Spectra c	Cell Wall Spectra per Complete Cell	Mean Cell Wall Area per Map [%]
Roots	20	187	134	39,262	294	67 ± 13
Stems	18	112	56	30,282	538	52 ± 13
Leaves	17	71	42	24,552	592	44 ± 17

^a Different xylem cells contained in all sections investigated by Raman mapping. Also partially investigated cell walls were counted; ^b Partially investigated cells were counted as parts of a complete cell and summed up; ^c Determined as cell wall spectra by automated separation by HCA clustering.