Eucalyptus urophylla and E. grandis were collected in January (summer) and August (winter) 2006 at the mature vegetative state from Goiania city Brazil, and identified by one of the authors (E.P.F.). Leaves from 5-11 randomized individual plants of the same age representing the local population were collected as homogenous samples in each season, dried at room temperature.

The results were submitted to Principal Components and Clusters Analysis which enabled four groups of oils to be distinguished with regard to specimens and harvest seasons: clusters I and II with only E. grandis samples collected in the cold and dry winter and the hot and humid summer, which were characterized by a high percentage of isoleptospermone (9.6% and 13.2%), alpha-pinene (12.2% and 24.7%), p-cymene (20.5% and 14.5%), and alpha-terpineol (14.3% and 4.9%), respectively; clusters III and IV only associated with E. urophylla samples collected in summer and winter with 1,8-cineole (36.6% and 44.7%) and alpha-terpinyl acetate (7.0% and 11.7%) rich oils.

Samples of Glechoma hederacea were collected at full flowering in seven localities in Vilnius district (Lithuania) at 2005: A - Salininkai, B -Zolyno, C - Mistunai, D -Antakalnis, E - Nemencine, F - Seskine, G -Zujunai.

More than half of the oils were rich in sesquiterpene hydrocarbons (56.5-67.9%). The most predominant compound was germacrene D (14.1-20.7%). The other main constituents were gamma-elemene (9.0-16.0%), beta-elemene (8.7-12.9%), phytols (2.8-15.6%), (Z)-beta-ocimene (2.2-8.5%), 1,8-cineole (92.2-5.4%), beta-ylangene (2.7-4.1%) and germacrene B (2.2-3.9%). Forty-three identified compounds made up 89.1-96.2%. Four oils (A, D-G) might be attributed to germacrene / elemene chemotype and three samples (A-C) containing marked amounts of phytols beside above compounds were of germacrene/elemene/phytols chemotype.

The plant material was collected in eastern Lithuania (July-August, 2002). Numbers of growing localities of H. arenarium with yellow (Y) and orange (O) flowers were as follows: Svencionys district (Zalavas) and Ukmerge district (Sventupe).

The 68 constituents identified comprised 73.8-90.7% of the total oil content. It was found that the principal constituents were: beta-caryophyllene (in three inflorescence and one leaf oil), delta-cadinene (in two leaf oils), octadecane (in one leaf oil) and heneicosane (in one inflorescence sample). Monoterpenes and oxygenated monoterpenes made up 4.0-13.9%, aliphatic hydrocarbons 0.4-35.3%, and sesquiterpenes 24.7-71.2% of the oils.

Plant material and isolation procedure: Aerial parts of the plant were collected from two regions, from Kazeroon in southern Iran and Shahr-e-kord in western Iran at the time of flowering in June 2002.

The main components of the oil of S. pilifera collected from Kazeroon, in southern Iran, were spathulenol (15.8%), cis-chrysanthenol (15.3%), beta-caryophyllene (8.4%) and cis-chrysanthenyl acetate (6.9%), while for the plant collected from Shahr-e-kord, in western Iran, they were cis-chrysanthenyl acetate (21.8%), linalool (18.9%), terpinen-4-ol (11.9%) and cis-chrysanthenol (9.2%).