The essential oils of Origanum vulgare subsp. hirtum plants collected
in late autumn from six localities of three distinct geographic areas
of Greece were analysed by means of GC and GC-mass spectrometry. A hig
h quantitative variation was found in the amount of the four main comp
onents; gamma-terpinene ranged from 0.6 to 3.6% of the total essential
oil, p-cymeme from 17.3 to 51.3%, thymol from 0.2 to 42.8%, and carva
crol from 1.7% to 69.6%. Plants collected from the northern part of Gr
eece were rich in thymol (30.3-42.8% of total oil), whereas those from
the southern part of the country were rich in carvacrol (57.4-69.6% o
f total oil). Furthermore, comparison with the essential oils obtained
from plants collected from the same localities in mid-summer shows no
ticeable differences in the total oil content and the concentration of
the four main oil components. Copyright (C) 1997 Elsevier Science Ltd
.