Article InformationThe present study was carried out to compare the chemical composition of the leaf essential oils (EOs) from six Psiadia species endemic to Madagascar, namely P. altissima, P. stenophylla, P. hispida, P. leucophylla, P. lucida and P. salviifolia. Three of these species (P. altissima, P. lucida and P. salviifolia) are traditionally used for treating diarrhea, stomach ache and skin diseases. They are also known for their antiseptic, expectorant, hemostatic, carminative and anti-inflammatory properties. The EOs of the six species were obtained by hydrodistillation and analysed by capillary GC-FID and GC-MS. Their oil yields ranged from 0.04% to 0.80%. 149 components were identified, accounting for 84.0 to 97.9% of the total composition. The EOs from the four species P. altissima, P. stenophylla, P. hispida and P. salviifolia showed similar chemical composition which was dominated by monoterpene (63.1-78.4%) and sesquiterpene (5.7-25.7%) hydrocarbons. The major compounds identified in these oils were β-pinene (17.2-46.5%), limonene (10.4-28.5%) and (Z)-β-ocimene (5.4-7.3%). The two other species exhibited qualitative and quantitative differences in the chemical composition of their EOs. The essential oil (EO) from P. lucida was found to be rich in sesquiterpene hydrocarbons (46.6%) and oxygenated sesquiterpenes (32.0%). α-cadinol (11.1%), α-muurolene (10.6%) and δ-cadinene (7.5%) were the main components. The P. leucophylla EO was characterized by a prominent content of sesquiterpene hydrocarbons (66.4%). The main compounds included βcaryophyllene (10.6%), δ-cadinene (8.9%) and (E)-muurola-4(14),5-diene (7.2%). This was the first report on the chemical composition of the EOs from P. stenophylla, P. hispida and P. leucophylla.