The aerial parts of A. roxburghiana var. purpurascens were collected during the mature vegetative stage in September from different altitudes (Bhaldana, 850 m; Bhatwari, 1218 m; and Mussoorie, 2205 m) of Garhwal Himalayas.

The oil yield was lowest (0.2%) in the plants collected from the relatively higher altitude of Mussoorie; it was rich in borneol (21.2%) followed by linalyl acetate (7.4%) and alpha- humulene (6.7%). The oils from plants collected from the lower altitudes of Bhatwari and Bhaldana yielded higher percentage of oils (0.8-0.85%) which were dominated by beta-caryophyllene (16.3%, 18.4%) followed by alpha-thujone (12.0%) in the former and eugenol (16.2%) in the later.

Leaves from mature plants of Artemisia nilagirica var. septentrionalis, before flowering, were collected from different altitudes in Himachal Pradesh such as Shimla (2210 m), Mandi (1044 m) and Manali (2050 m) in June 2005.

The major constituents of the oil show variation with changes in altitude. At lower, middle and higher altitudes, the major constituents of the oil were caryophyllene oxide (28.6%), borneol (35.8%) and camphor (46.9%), respectively. The percentages of alpha-humulene and trans-beta-guaiene also increased, but the percentage of sabinene, trans-sabinene hydrate, 4-terpineol, caryophyllene oxide and humulene epoxide-II decreased with an increase in altitude. The characteristic compounds observed in the plants from lower altitudes were 2-hexene-1-ol, beta-thujone, thujanol, myrtenol and linalyl acetate, while the higher altitude plants were characterized by the presence of alpha-pinene, beta-pinene, limonene, linalool, gamma-gurijunene, germacrene-D and farnesol.

Aerial parts of endemic pichana were harvested in December 1996 at different localities of northern Patagonia. Origin: Planicie Banderita, Dept. Confluencia, Province of NeuquCn. Habitat: altitude, 327 m; average temperature in the station, 21.8 ℃; annual precipitation, 125 mm; sandy soils. Aerial parts (5 kg, 2 kg of dried material;humidity, 11%) from four well developed plants at the fullflowering stage (December, 1996). Sample 2 : Origin: RincBn de 10s; Sauces, Dept. of Pehuenclies, Province of Neuqukn. Habitat: altitude, 750 m; average temperature in the station, 20.9 ℃; annual precipitation, 147 mm; sandy and gritty salty soils. Aerial parts (5 kg, 1.85 kg of dried material, humidity, 10%), from two well developed plants at the full flowering stage, and after several days copious rains (December, 1996). Sample 3: Origin: Coronel GBmez, Dept. General Roca, Province of Rio Negro. Habitat: altitude, 242 m; average temperature in the station, 22.5 ℃; annual precipitation, 179 mm; sandy and stony soils. Aerial parts (4.5 kg, 1.3 kg of dried material, humidity, 9%), from 12 young plants at the beginning flowering stage (December, 1996).

Fifty-four components, representing approximately 84.6-97.4% of the oil samples, were identified. The samples consisted mainly of hydrocarbons and oxygenated monoterpenes. The major constituents were limonene (28.7-56.7%), 6R-7R-bisabolone (3.2-9.1%), sabinene (0.1-11.0%) and citronellal (2.4-5.2%). Significant differences among the content of the three samples could be the result of changes in the climatic conditions (sample 2: Rincon de los Sauces, Province of Neuquen, after strong rains) or by translocations in different parts of the plant (sample 3: Coronel Gomez, Province of Rio Negro, more leaves and less stems).

Wild growing D. graveolens samples were collected from Bekaa-877′ (4 samples) and Sannine-1842′ (3 samples) during the flowering period, between September and November of 2003.

The major differences in oil composition between the two populations are the variation in the concentrations of T-cadinol and borneol. The differences can also be ascribed to the distinct climatic pattern of the two samples: Sannine is located in the Mount Lebanon chain of mountains and characterized by heavy precipitations and snow, while the Bekaa valley is shielded by this same chain of mountains, resulting in dry summers and cold winters with less humidity and precipitations.

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%).