The content and pattern of piperidine alkaloid accumulation in Picea pungens, the Colorado blue spruce, was studied as a function of growth stage and plant part. Qualitative and quantitative differences were encountered between early seedlings, mature trees, needles, stems and other plant parts. A new natural piperidine imine alkaloid, 2-methyl-6-propyl-1,6-piperideine, was found and postulated to be an intermediate leading to epidihydropinidine, the major alkaloid found in spruce needles.