Rachis lignification of Couroupita guianensis Aubl

ABSTRACT 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%.