In the course of investigating lipophilic air pollutants in the epicut
icular wax of Pinus sylvestris L. needles, elemental sulphur, S-8, was
found in all samples. An investigation was conducted to determine the
origin of this substance. No correlation between the level of S-8 in
the needles and human activities in the sampling area could be found,
contrary to what would have been expected of an anthropogenic compound
. The internal lipids of P. sylvestris as well as the epicuticular wax
of historical herbarium material and seedlings grown in clean, filter
ed air, and the epicuticular wax of several other species, both gymnos
perms and angiosperms, also contained S-8. Quantitation of S-8 in P. s
ylvestris gave levels of 7.2 +/- 2.9 mu g/g wax, 3.8 +/- 1.9 mu g/g in
ternal lipid and 0.43 +/- 0.17 mu g/g total needle dry weight. Almost
0.1% of the total sulphur in pine needles is S-8, and approximately ha
lf of the total S-8 is found in the wax. The results suggest that S-8
is endogeneous in many higher plants. A function for S-8 as part of an
antifungal defence system is possible.