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.

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.

One hundred grams of mature leaves were collected from 2 to 10 widely spaced trees per site and sent to Sydney for analysis as soon as possible after collection. Samples usually arrived in the laboratory within 48 h of collection. The majority of the sampling was done between December 1998 and October 1999. Seasonal trends in oil yields and composition are confounded in the data on geographic variation, but these were considered minor in the context of this study.

Chemotype 1 is comprised of E-nerolidol (74-95%) and linalool (14-30%) and is found from Sydney, north along the east coast of Australia to Selection Flat, New South Wales, with an isolated occurrence near Maryborough, Queensland. Two divisions occur in this chemotype which are based on the presence or absence of significant proportions of linalool (14-40%). Chemotype 2 contains 1,8-cineole (10-75%), viridiflorol (13-66%), alpha-terpineol (0.5-14%) and beta-caryophyllene (0.5-28%) in varying proportions and order of dominance in the oils. It is found throughout the distribution of the species, from Sydney to Papua New Guinea and New Caledonia. Within chemotype 2 there appears to be a continuous spread of oil composition without formation of any further discrete divisions as in chemotype 1. Analyses have shown that M. quinquenervia trees that occur at latitudes south of 25d S have high oil yields (1-3% w/w%, fresh leaves) and comprise chemotypes 1 and 2. North of 25d S, however, chemotype 1 does not occur and oil yields amongst the Australian populations are uniformly low (0.1-0.2%).

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.