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 experiments were performed in the experimental field of the Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences (Danzhou, Hainan, China; localization 19.52° N, 10⁹.50° E; altitude 118 m; annual average precipitation 1815 mm; annual average temperature 23.5 ℃ ;the soil characteristics are : "Organic matter (g/kg) 11.37;pH 4.94;N (g/kg) 0.51;P (mg/kg) 25.33;K (mg/kg) 33.89). The experimental B. balsamifera plants were one-year old, and were propagated by the seeds collected from B. balsamifera planted in the experimental field of the Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences. They were planted with a planting spacing of 80 cm × 80 cm. On the 20th day of each month (from September 2014 to December 2014, which is the traditional harvest time), 30 one-year old B. balsamifera plants were randomly collected. Their young leaves (leaves on young shoots), mature leaves (leaves which are mature but without yellow spots), senescent leaves (leaves with yellow spots and those with dark brown leaf tips), dead leaves (leaves that have turned dark brown), young shoots (stems from buds to 10-20 cm part without woody parts), and young stems (green stems and not completely woody) were collected. These samples were divided into three parts (replicates), dried under shade, and ground to a fine powder (20-mesh sieve), packed in zip-lock bags, and stored in the refrigerator (4 ℃ ) for oil extraction.

Time of growth and type of B. balsamifera plant organs influence the production of oil, its composition, and antioxidant activity. The essential oil level in the young leaves was the highest, followed by mature leaves and senescent leaves, and the oil content was higher in October. A total of 44 compounds were identified. In the essential oils of leaves, the main ingredient is l-borneol, and the content was the highest in senescent leaves and in December. Variations in oil yields did not show the same pattern as the percentages of l-borneol in the essential oil. In the essential oils of young shoots and young stems, the main composition was dimethoxydurene. Therefore, the time of harvest and type of plant organs should be distinguished based on the different harvesting purposes. To extract the volatile oil, the aboveground parts except stems in October should be chosen for harvest. To get a high content of l-borneol in volatile oil, it is more appropriate to select the leaves in December. The antioxidant activity was evaluated using DPPH and BCB assays in this study, and the results proved that the essential oils of B. balsamifera showed a certain antioxidant activity, and the beta-carotene bleaching activity is far stronger than the DPPH radical-scavenging capacity. The young leaves and young shoots showed stronger antioxidant activity due to the high content of dimethoxydurene, beta-caryophyllene, and alpha-caryophyllene.

Plant material: Samples of B. gibraltarium were gathered in November 1995 during the fruiting period (F), in May 1996 during the pre-flowering period (PF), in July 1996 during the full flowering period (FF), and in September 1996 during the late flowering period (LF) from El Zumbel area (UTM: 30SVG3278) . Every sample consisted in the whole aerial parts of five single plants growing wild near one to another. Once the plants reached the laboratory, they were airdried for seven to 15 days, and separated by parts, i.e., leaves, stems, umbel rays and, when present, fruits.

In the leaf oils, sabinene (12.0-33.9%) and limonene (7.8-23.4%) were the main components, the sabinene level being minimum in full flowering and maximum in fruiting. In stem oils, sabinene (4.7-21.6%) and 2,3,4-trimethylbenzaldehyde (9.3-13.6%) were the main components, the sabinene level being minimum in pre-flowering and maximum in full flowering. In umbel ray oils, sabinene (20.7-43.1%) was the first component in all the phenological periods, followed by alpha-pinene (7.3-28.2%). Both monoterpenes increased their levels in late flowering and reached minimum amounts in fruiting.

Hemp plants (cultivar USO-31) were cultivated for the production of hemp herb under non-standard agro-climatic conditions on clay-stony soil in the southern part of central Slovakia. The size of the managed soil was 0.42 hectares. No pre-crop was applied before sowing. In the autumn, classic manure was used as fertilizer, which was subsequently ploughed. In the spring, shallow ploughing was carried out. The seeds were sown by hand on 20 April 2019. Subsequently, the growing season began, which lasted until 12 September 2019, when it ended with the mowing of the stand using a drum rotary mower pulled by a tractor. During the growing season, the samples were taken three times, focusing on inflorescences and leaves. The first samples were harvested on 30 June 2019, before the flowering of the plant. The plants were short and reached a height of about 30 cm. The second samples were harvested on 3 August 2019 (the plants were already in the flowering phase). The inflorescences in the upper parts of the plant reached lengths of 2 to 30 cm. In this phase, there were also male inflorescences in the stand, which were already in a more advanced stage of flowering. The height of the plants ranged from 20-150 cm. The third sample was harvested on 1 September 2019, after flowering. The samples of hemp (the same genus) after flowering harvested in 2018 were analyzed too. Hemp plants from the year 2018 season were much more developed, reaching a height of 2 m, and were more densely inseminated.

The highest content of polyphenolic compounds was analyzed in the sample harvested before flowering (17.217 mg/g). According to this study, the harvest in June (before flowering) is the most convenient for the achievement of the highest antioxidant activity and polyphenolic content. Among the secondary metabolites in hemp, terpenes and cannabinoids are the most attractive for research and further processing. The highest amounts were found in the sample collected during flowering. The concentrations of major terpenes beta-caryophyllene and alpha-humulene were maximal during flowering, at 72.10 and 36.75 mg/g respectively. The accumulation of cannabinoids was also highest at this stage. The concentration of cannabidiol was 3.81 mg/g. The harvest of female plants is essential in July due to the CBD concentration maximum.

Six samples of Cassinia laevis R. Br. (coughbush, wild rosemary) were gathered from Lowood, 45 km west of Brisbane to Murphy's Creek area 100 km west of Brisbane, Australia from 1994 to 1998. Samples were identified by a LAEV prefix. LAEV 1 and LAEV 4 were collected from the roadside verge of the Gatton-Toowoomba bypass road (Lat. 27° 32′ 21″ S; Long. 152° 14′ 28″ E). LAEV 2 and LAEV 5 were collected from a different location in the same area (Lat. 27° 33′ 08″ S; Long. 152° 15′ 00″ E). LAEV 7 were collected from the Murphy's creek area (Lat. 27° 31′ 05″ S; Long. 152° 04′ 15″ E), growing on the roadside and in an adjacent paddock. Sample LAEV 9, was collected from the roadside area of the Warrego Highway (Lat. 27° 32′ 10″ S; Long. 152° 27′ 12″ E). The collected leaf and flower samples had aromas of trampled grass with a slight hint of curry.

Spathulenol was the major compound in flower oils (8-12%) compared to leaf oils (0.3-4.0%) which had ledol(37.5-53.6%) as the major compound.

Plant selection and virological tests: Before effecting the collection procedure, heathy and infected plants of E. purpurea grown in the open field at the Herb Garden of Casola Valsenio were selected and labelled by visual inspection of their aerial parts. The infection by CMV was associated with symptoms on both leaves and flowers. The most characteristic symptoms are yellow mosaic, ring and line-patterns on crinkled and deformed leaves that drop prematurely. The flowers, which may be smaller than normal, show color breaking with white or pale stripes on red petals. Shortening of the internodes is also very common, giving the plant a bushy appearance known as stunting. In Italian environmental conditions, these symptoms are best visible in the summer. On the other hand, plants appeared symptom-free were collected as healthy material. Plant collection: About 3-4 Kg fresh aerial part materials (70% stems, 10% leaves and 20% flowers) of healthy E. purpurea plants were collected in June 2000 at almost the end of flowering. An equivalent quantity of CMV-infected plants (evaluated by DAS-ELISA) was also collected; the percentage of leaves in the infected infected was about 6.0% as due to CMV presence that caused the premature leaf drop.

The oil from healthy material was rich in germacrene D (57.8%) and was more abundant. The infected materials afforded a lower oil content and significant quantitative variations in the oil composition. In particular, the observed percentage of germacrene D (52.6%) was reduced as were other sesquiterpene hydrocarbons. These variations, tested to be significant for all the compound-class fractions and individual major components, were ascribed to the cucumber mosaic cucumovirus (CMV) infection, the only fixed-effect variable that might affect the oil composition.

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.

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.

Plant material was collected at vegetative stage (stems and leaves,September 2005) and at flowering stage (leaves and flowers,December 2004), inCuritiba,Parana state, Brazil.

Thirty-four components were identified, representing more than 80% of total oil. The major components were beta-caryophyllene (flowers-12.8%), caryophyllene oxide (stems-17.2%), globulol (stems-16.5%; leaves-22.5% at vegetative stage and 18.9% at flowering stage), 1-epi-cubenol (stems-10.9%), epi-alpha-muurolol (stems-16.8%) and alpha-cadinol (stems-12.1%; flowers-10.1%).

Aerial parts of H. altaicus Willd. (Novopokr.) plants were randomly collected from the wild at four different altitudes, as described below, during the 1999-2001 vegetation periods. All the collections of the plant samples were carried out during massive bud formation and the beginning of flowering. Sample # 1 (3.4 kg) was collected on July 14, 1999 from LAT: 53° 05′ LON: 85° 00′, 330 m, Altai Region, Troiszkii Raion, around the village of Taldinka, 4-5 km below the Bolshoi Rechke, facing southwestern Sopki, Tipchakovo-Heteropalusovo-Pavilnaya steppe. Sample # 2 (10.5 kg) was collected on July 28, 1999 from LAT: 51°, LON: 86° 40′, 600 m, Altai Republic, Ongudaiskii Raion, at the right side of the delta of Lake Ursup, surrounding Stepushka village, along the roadside. Sample # 3 (8.5 kg) was collected on July 30, 2000 from LAT: 51° 39′ LON:79° 59′, 120 m of Altaiskii Krai, Litovskii Raion, 2 km southwest of the Ustianka village, along the roadside. Sample # 4 (6.5 kg) was collected on August 2, 2001 at LAT 50° 11′ LON 87° 53′, 1550 m of Altai Republic, Kosh-Agachiskii Raion, 24 km away from Kurai village, towards North-Tchuiskoe mountain chain following the right side of lake Tete where there is a mixture of heavy weeds.

The oil obtained from 330 m had alpha-pinene (18.6%), myrcene (18.6%), beta-phellandrene (17.2%), (E)-beta-ocimene (12.9%) and germacrene D (11.9%), while samples from 600 m consisted of myrcene (26.4%), alpha-pinene (23.2%), beta-phellandrene (18.0%), (E)-beta-ocimene (9.9%), germacrene D (4.3%) and sabinene (4.2%). The oil from 120 m had -pinene (22.0%), beta-phellandrene (21.6%), myrcene (19.5%), trans-beta-ocimene (11.3%), germacrene D (7.2%) and limonene (4.5%) as major components. At 1550 m the major components were germacrene D (22.0%), myrcene (18.0%), beta-phellandrene (14.0%), alpha-pinene (11.3%) and (E)-beta-ocimene (9.2%).

Hyptis marrubioides were collected in March 2003 at the mature vegetative stage from their natural habitat; 20 randomised individual plants at the same age representing the local population were collected as homogenous samples from each locality: (A) Lavras (21° 14′ S/44° 59′ W), at an altitude of 919 m; (B) Tiradentes (21° 6′ S/44° 10 m W), 927 m.

The results were submitted to Principal Component and Cluster analysis which allowed three groups of oils to be distinguished with respect to sampling site and post-harvested process: cluster I (fresh leaves and fresh or dried stems from Lavras site) with high percentage of caryophylla-4(14),8(15)-dien-5beta-ol (16.7%) and eudesma-4(15),7-dien-1beta-ol (12.8%); cluster II (dried leaves and stems from Tiradentes site) with epi-longipinanol (16.2%) rich oil, and cluster III (dried leaves from Lavras) containing a high content of beta-caryophyllene (17.4%) and alpha-copaene (10.1%). Canonical discriminant analysis showed that is possible to accurately predict 100% well-classification in the original clusters using beta-caryophyllene, epi-longipinanol and caryophylla-4(14),8(15)-dien-5beta-ol as predictor variables. The whole or sliced plant materials resulted in similar chemical composition.

Plants from Horto de Plantas Medicinais of Universidade Federal de Lavras (UFLA) were cultivated in the form of a randomized block with six replications in an experimental field at Setor de Horticultura, UFLA, in Lavras city (S 21° 14′, W 44° 59′, 920 m). Samples were collected four times at 3-month intervals from March to December 2004.

There was a significant difference for oil contents in the different seasons. The lowest oil content was obtained in the summer (about 50% inferior to the other seasons). Methyl (E)-cinnamate was obtained as the major compound (86-90%) of the 14 identified components.

Experimental: Two hundred grams of healthy mature intact leaves were harvested from each of the taxa growing on their own rootstocks at the UC South Coast Research and Extension Center. flocc = P. americana var. floccosa from Mexico D-7; stey = P. americana var. steyermarkii from Mexico El Salvador 3-22-16; nubi = P. americana var. nubigena from Guatemala 45-C-1; mex = P. americena var. drymfolia from Tasco, Mexico; guat = P. americana var. guatemalensis cult. Nimlioh from Florida; bwl = P. ameticana var. americana cult. Trapp from Florida.

Analysis of oils showed the presence of over 90 components, of which 76 were identified. P. schiedeana oil was found to contain alpha-pinene (23.7%), beta-pinene (23.2%) and beta-caryophyllene as major components. The major constituents of P. americana var. floccosa and P. americana var. steyermarkii were alpha-pinene (10.9%, 7.6%), beta-pinene (20.6%, 10.4%), alpha-terpineol (9.6%, 7.9%), beta-caryophyllene (12.6%, 8.4%), viridiflorene (0.1%, 10.3%) and globulol (0.1%, 9.2%), respectively. The oils of P. americana var. nubigena and P. americana var. drymifolia contained alpha-terpineol (18.4%, 393%) and methylchavicol (12.4%, 40.2%), as major components, respectively. P. americana var. guatemalensis was found to be rich in beta-caryophyllene (38.3%), while the oils of P. americana var. americana and P. primatogena contained alpha-pinene (27.5%) and beta-pinene (40.9%), and alpha-pinene (24.6%), beta-caryophyllene (20.7%) and germacene D (10.1%).

Five different populations of P. spicatus were collected in different geographical regions of the northeast of Brazil. Populations I: (Locality: Morro do Chapeu,Bahia, harvesting: 02.19.94); Populations II: (Locality: Maranguape,Ceara, harvesting: 06.01.97); Populations III: (Locality: Jacobina,Bahia, harvesting: 02.19.94); Populations IV: (Locality: Cocalzinho,Ceara, harvesting: 02.22.94); Populations V: (Locality: Sitio dos Moreiras,Pernambuco, harvesting: 02.22.94)

The aliphatic ketones 2-undecanone, 2-tridecanone and 2-pentadecanone were present in samples of all populations. 2-Tridecanone (1.7-84.7 %) was detected in 30 out of 34 samples analyzed. It was the main component in all samples of root barks, except one where 2-pentadecanone (24.7%) was the major component. 2-Undecanone, beta-eudesmol and sabinene were the major components of leaf oils.

Wild growing Tanacetum dolichophyllum samples were collected during the period of full flowering, between September-October 2009 from high alpine meadows of Western Himalaya (Uttarakhand, India): Sample I (Dayara, altitude 3200 m) and Sample II (Tungnath, altitude 3800 m).

Plant collected from Dayara meadow (Sample I) afforded cis-lanceol (11.8%), beta-pinene (10.7%), (E)- beta-farnesene (7.4%), alpha-bisabolol (7.2%), beta-eudesmol (5.2%) and terpinen-4-ol (5.1%) as the major constituents, whereas in the sample collected from Tungnath (Sample II) beta-eudesmol (31.4%), alpha-bisabolol (10.7%) were the most abundant components followed by neryl acetate (5.8%) and (E)-beta-farnesene (5.7%). The composition was dominated by sesquiterpene hydrocarbons and oxygen containing sesquiterpenes (49.2-71.1%). The oils are clearly different from those of all other previously reported T. dolichophyllum oils.