The leaves and terminal branchlets were collected in the Dimbulah region of north eastern Queensland, Australia. The first collection (R99-218) was located 5 km north and the second collection (R99-219) 30 km west of Dimbulah.

Two chemical forms yielding 0.6% and 0.3% on a dry weight basis were found to be rich in kessane (88.8%) and alpha-pinene (16.2%), respectively.

The 36 'Genovese' and 24 'Foglia di Lattuga' samples preliminarily analysed were grown in Tavazzano (MI), and harvested at flowering, from 5th to 10th August 1998. The breeding program started in 1999, by crossing several selected lines of 'Genovese' with 'Foglia di Lattuga' and 'Compatto'. Selected F1 plants were selfpollinated in 2000. Plants of the F2 (2001), F3 (2002) and F4 (2003) generations were selected on the basis of agronomic and morphologic traits, and self-pollinated. Only the seeds from self pollinated plants with satisfactory essential oil content and composition were used to obtain the next generation. In 2004, some F4 plants were replanted in order to evaluate their stability in relation to environmental variations. All leaf harvests were carried out at flowering.

Genovese' showed higher essential oil and linalool content, with almost total absence of methyl chavicol, very abundant in 'Foglia di Lattuga'.

Aerial parts of Solidago virgaurea plants were randomly collected from the wild at two different altitudes, as described below, during the 2000 vegetation period. All the collections of the plant samples were carried out during massive bud formation and the beginning of flowering stage. Sample # 1, LTS00-46; 10 kg of the sample was collected on July 31, 2000 at LAT: 51° 07′ LON: 81° 10′ HEI 290 m from Altai land, Lokteev district, near the village of NovoMikhaylovskoe, on the left bank of the Aley River, outskirts of pine forest, fire area, sandy soils. Sample # 2, LTS00-57; 5.6 kg of the sample was collected on August 3, 2000 at LAT 51° 14′ LON 82° 28′ HEI 650 m from Altai land, Kur'in district, around the Kolyvanm quarries, with diverse turf grasses, along the river bank of Aley.

The main components from 290 m were alpha-pinene (36.5%), myrcene (14.8%), beta-caryophyllene (10.5%), germacrene D (8.2%), beta-pinene (7.1%) and limonene+beta-phellandrene (6.4%). The oil from the sample collected at 650 m had benzyl benzoate (57.0%), beta-caryophyllene (6.3%), germacrene D (6.0%), alpha-pinene (4.4%) and alpha-humulene (4.0%) as major components, suggesting polymorphism or the existence of different chemoytpes.

Talauma ovata was collected from October 2003 to February 2005. Leaves and trunk bark from the same set of plants were collected in the four seasons: spring (October 15th, 2003), autumn (April 10th, 2004), winter (July 17th, 2004) and summer (February 15th, 2005). In addition, trunk bark was also collected on January 22nd, 2004 (summer). The plant material was harvested from wild-growing population in Santos Dumont City, Minas Gerais State, Brazil, (21° 28′ 03″ S, 43° 39′ 26″ W), at 1000 m of altitude.

In each season the composition of trunk bark oils was similar to leaf oils, with mainly quantitative differences. However considerable seasonal variation was observed. Significant levels of monoterpenes were found only in autumn. The content of oxygenated sesquiterpenes was highest in samples of spring (October) and decreased in summer (January and February), reaching the lowest level in autumn (April) and increasing again in winter (July). In trunk bark oils the main constituents were: spathulenol, alpha-eudesmol, linalool, trans-beta-guaiene and caryophyllene oxide. The major component in all samples of trunk bark was spathulenol. Its level was highest in October (46.8%), decreased in January (33.3%), remained stable in April and July (18.0%) and increased again in February of next year (27.7%). Levels of alpha-eudesmol were high in spring (13.0%) and autumn (11.5%). Linalool peaked only in April, while trans-beta-guaiane peaked in July (11.1%). Caryophyllene oxide ranged between 10.7-2.0%. The level was highest in January, decreased regularly until July and increased slightly again in October. In leaf oils the main components were: spathulenol, germacrene B, germacrene D, caryophyllene oxide and viridiflorol. Spathulenol was the major component in sample of spring (34.4%), but decreased gradually until winter, when reached the lowest level (9.4%). Caryophyllene oxide showed a similar pattern, varying from 14.1% (spring) to 2.4% (winter). An inverse effect was observed for viridiflorol, which increased from 0.1% in October to 13.7% in July. Important levels of alpha-eudesmol were observed in October (12.3%) and February (9.5%). The percentage of germacrene D was highest in summer, while germacrene B showed high amounts in autumn and winter. The seasonal changes in oil composition of T. ovata can be associated with cycle of life of plant (flowering, fruiting and vegetative stages) and climatic parameters such as intense raining in the spring and summer.