- The dibenzodioxocin lignin substructure is abundant in the inner part of the secondary wall in Norway spruce and silver birch xylem. Kukkola, E.M., Koutaniemi, S., Pöllänen, E., Gustafsson, M., Karhunen, P., Lundell, T.K., Saranpää, P., Kilpeläinen, I., Teeri, T.H., Fagerstedt, K.V. Planta (2004)