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.