The wood of P. nigra vars pallasiana and pyramidata was analysed with
regard to the main components lignin and holocellulose, as well as ext
ractives. The lignin content was unusually low. Most of the extractive
s were fatty and resin acids. The var. pyramidata is richer in resin a
cids and differs also in the ratio of abietane- and pimarane-type acid
s from var, pallasiana. Some differences were also found in the sterol
- and neutral diterpene-containing fractions.