Abstract The essential oil of the leaves and stems of Limnophila chinensis ssp. aromatica collected from a North American market and examined by GC/MS was dominated by 53.12±2.91% limonene and 12.19±1.29% cis-4-caranone (3-caranone). This is the first report of trans- and cis-4-caranone in a natural essential oil.