From a preliminary study, conyzic acid, C₂₀H₂₆O₃, a diterpene resin acid isolated from Conyza stricta Willd was suggested to be Δ¹-polyalthic acid [1]. In a recent communication Bohlmann and Fritz [2] reported the characterization of secconidoresedasaure (1), a novel diterpene acid isolated as its methyl ester (2) from Nidorella resedifolia. Later Tandon and Rastogi [3] isolated from Conyza stricta, a diterpene acid designated as strictic acid and established its structure as 1, but the orientation of the methyl and the side chain at C-9 are reversed. The similarities of the physical data of conyzic acid and strictic acid prompted us to reinvestigate the structure of the former. ¹H NMR and ¹³C NMR spectra of conyzic acid which were found to be identical with those of strictic acid were compatible with the structure 1. Moreover, ¹H NMR data reported for methyl secconidoresedate [2] were comparable with those of methyl esters of conyzic acid and strictic acid. The identity of conyzic acid, strictic acid and secconidoresedasaure was finally confirmed by direct comparison of the methyl esters of the three acids. Although there is no direct evidence with regard to the configuration at C-9, β-orientation of the C-9 methyl seems to be more probable from the biogenetic point of view. Secconidoresedasaure occurs with diterpenes having a β-methyl at C-9. Moreover, the biogenetic pathway for formation of this acid suggested by Bohlmann and Fritz [2] is in conformity with the β orientation of the C-9 methyl. It is noteworthy that contrary to the observations by Tandon and Rastogi [3], the acid (1), or its methyl ester, did not show UV absorption maxima above 212 nm. It has been verified by Dreiding model inspection [2] that this non-existence of long wavelength UV absorption is due to the chromophoric system not lying in one plane. During isolation of 2 by esterification of the acid fraction by CH₂N₂, a compound was obtained which was found to have the molecular formula C₂₂H₃₀N₂O₃ by high resolution MS. Study of the ¹H NMR and ¹³C NMR spectra of the compound revealed its structure as 3 which is, evidently, a diazomethane adduct of 2.