The EO of Egyptian C. plicata ecotype contained thirty five compounds.
(−)-caryophyllene oxide, Z-nerolidol and .tau.cadinol are the major sesquiterpenes.
This EO showed a strong allelopathic activity against B. pilosa and U. picroides.
EO of C. plicata aerial parts showed a significant antioxidant activity.
EO of C. plicata could be used as ecofriendly green bio herbicides.