The aim of this study was to substantiate the possible influence of gravity on the lignin
content in the rachis of Couroupita guianensis Aubl., since it grows in favor of gravitational
forces. Chemical analysis, medium infrared (FTIR) spectroscopy and microspectroscopy
were conducted, coupled with supporting images obtained from an optical microscope. The
rachis lignin content was 5.56%, composed of both syringyl and guaiacyl units; the latter being
predominant, showing that the gravity force influenced the lignin process when compared with
lignin content of main stem, 17%.
