Aside from water, wood has three main parts. Cellulose, a crystalline polymer derived from glucose, constitutes about 41–43%. Next in abundance is hemicellulose, which is round 20% in deciduous trees but near 30% in conifers. It is principally five-carbon sugars that are linked in an irregular manner, in contrast to the cellulose. Lignin is the third element at around 27% in coniferous wooden vs. 23% in deciduous timber.