Plant material of A. verlotiorum was harvested near Marseille (France) in May (before blooming) and November (full flowering) 2000.

For the oil from the vegetative plants, 50 compounds, representing 99.8% of the oil were characterized. Fifty-nine compounds, representing 99.6% of the oil were identified in the oil from flowering plants. In both cases, the constituents were mainly oxygenated monoterpenes (74% and 88%). The composition of each oil showed only a few differences, as the main components were alpha-thujone (55% and 44%), 1,8-cineole (5% and 15%), beta-caryophyllene (13% and 7%) and beta-thujone (5% and 11%), in the oils of the vegetative plant and flowering plant, respectively. The proportions of the oxygenated compounds seemed to increase during flowering.

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.