The essential oil composition is reported for Plectranthus ciliatus, Plectranthus zuluensis and their putative hybrid. The essential oil chemistry is in support of morphological data and pollination studies, which have indicated a natural hybrid between P ciliatus and P zuluensis. The hybrid plant contains terpenoids from both putative parents together with 'hybrid compounds,' which are not present in any of the two parents. The composition of the essential oil obtained through microdistillation is virtually identical to the analysis of the hydrodistilled essential oil. (c) 2005 SAAB. Published by Elsevier B.V. All rights reserved.