Hemicelluloses have a backbone of 1,4-linked β-D-pyranosyl residues in which O4 is in the equatorial orientation (e.g. Glc, Man, and Xyl). Xyloglucan is the predominant hemicellulose in the primary walls of dicots and non-graminaceous monocots and may account for up to 20% of the dry weight of the primary wall. Xyloglucan has a backbone composed of 1,4-linked β-D-Glcp residues. Up to 75% of these residues are substituted at O6 with mono-, di-, or triglycosyl side chains.