Crosses between white spruce (Picea glauca), red spruce (P. rubens), blue spruce (P. pungens), and (P. glauca x P. pungens) from several seed and pollen parents were made during 1974-76. The seeds were grown for 6 months with the aid of continuous illumination and several characters were measured to verify the hybridity of the seedlings. Hybrids of rubens with glauca and (glauca x pungens) were verified on the basis of differences in needle color, number of needle serrations, and concentrations of 3-carene, limonene, and -pinene in the cortical oleoresin. P. glauca x pungens hybrids were verified with more difficulty by a combination of needle curvature and 3-carene concentration. The backcrosses, (glauca x pungens) xglauca and (glauca x pungens) x pungens, were differentiated from each other by growth rate, needle curvature, and concentrations of 3-carene and -pinene. For most traits, putative hybrids were intermediate to their parents. However, F2 glauca x pungens hybrids were severely stunted, possibly owing to consanguinity of the parents. Forest Sci. 28:129-134.