Abstract
The application of volatile leaf oil analyses in chemosystematic studies of North American spruces was investigated. The optimum conditions for sampling and recovery of oil from the foliage of local Picea glauca (Moench) Voss and P. mariana (Mill.) B.S.P. were determined. Each oil was analyzed qualitatively and quantitatively by gas–liquid chromatography. Single needle analysis was also employed. No qualitative and relatively little quantitative variation was found to occur at different sides or heights of a single tree, between trees of different ages, nor at different harvest times between late summer and early winter. Hence, conditions have been found which give a characteristic terpene distribution pattern which may serve as an independent chemotaxonomic character.