Walnut is the common name of the tree species of the Juglans genus of the family Juglandaceae (walnut family), with single feathery leaves arranged opposite each other and aromatic odour and the fruits of these trees. They are deciduous trees in winter. The core of young shoots is compartmentalised. Buds are covered with few scales. The margins of the leaflets are finely toothed in some species and smooth in others (whole-edged). The number of leaflets varies between (3) 5-23 depending on the species.
Walnut shell consists of 49.7% polysaccharides, 29.9% lignin and 10.6% other H2O extractive substances. It also contains 35% lignin and 55.2% holocellulose (30.4% and 24.9% as a-cellulose and hemicellulose respectively).
Other compounds: (E)-caryophyllene, germacrene D (%7,1-%22,5), juglon, α-hydrojuglon ve δ-kadinen