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A sampling method for determining the volatile terpenoid composition from single needles of seven Tsuga species was developed using headspace solid-phase microextraction (SPME). A reproducible sampling method for the volatile components was generated by examination of sample storage, method of needle cutting, and headspace sampling duration. Following SPME collection of the volatile compounds from the seven Tsuga species, gas chromatography/ion-trap mass spectrometry was used to identify 51 terpenoids present in the needle headspace. A semiquantitative method was devised to express individual terpenoid amounts as a percentage of all of the identified peaks in the chromatogram. The semiquantitative results permitted facile interspecies comparison using principal component analysis. Two components were able to account for 90% of the variance and were interpreted as a “species …