Spruce

Overall view of spruce tree in a field at a tree farm.

Description

Spruce (Picea spp./Pinaceae). The genus Picea contains about 30 species 7 native to North America [1], 2 to Mexico [1], and 20 to Eurasia [1]. Microscopically, the wood of all species in this genus looks alike in their basic anatomy, with the exception of Sitka Spruce (Picea sitchensis) from western North America. It consistently contains crystals in its rays, as do the 3 European species on rare occasions. The commercial species native to North America are listed below.

Eastern North America
Common Name Scientific Name
Black Spruce P. mariana
Red Spruce P. rubens
White Spruce P. glauca

Tech Sheets

https://research.fs.usda.gov/silvics/black-spruce

https://research.fs.usda.gov/silvics/red-spruce

https://research.fs.usda.gov/silvics/white-spruce

Comparison to Other Softwoods

Key to Softwoods

Close up view of a spruce branch with cone.

Characteristics

Characteristics found in the Spruces (Picea spp.):

  • Resin Canals present
  • Epithelia with thick walls
  • Pits on ray tracheids either dentate (Picea type 2) or angular (Picea type 1)
  • extremely rare appearance of crystals in European species

Slides (Click on each image to view a larger image)

WOOD SLIDES

Microscope slide of transverse section of Spruce wood with arrows identifying sections of earlywood, latewood, the growth ring boundaries, and resin ducts.
Microscope slide of transverse section of Spruce wood at greater magnification with arrows pointing to resin ducts.
Microscope slide of transverse section of Spruce wood at greater magnification with arrows identifying location of the axial tracheids, ray and resin ducts.
Microscope slide of radial section of Spruce wood with arrows identifying the ray tracheid pits.
Microscope slide of tangential section of Spruce wood with arrow identifying the location of the radial resin duct.
Second microscope slide of tangential section of spruce wood with arrow identifying the location of the radial resin duct.
Microscope slide of tangential section of Spruce wood. Arrows point to the location of the rays and the radial resin duct.

CHARCOAL SLIDES

Microscope slide of radial surface of Spruce charcoal. Arrows point to the location of the growth ring boundary and the rays.
Microscope slide of radial surface of Spruce charcoal under greater magnification. Arrows identify the location of axial tracheids and the rays.
Microscope slide of tangential surface of Spruce charcoal. Arrows identiy the location of the rays and a resin duct.
Microscope slide of transverse section of Spruce charcoal. Arrows point to the growth ring boundaries and voids caused by pyrolysis.
Microscope slide of transverse section of Spruce charcoal. Arrows point to the growth ring boundary which separates the earlywood from the latewood. Another arrow identifies the location of a resin duct.
Microscope slide of transverse section of Spruce charcoal under greater magnification. Arrows point to the growth ring boundary which separates the earlywood and latewood. Additional arrows identify the resin duct and rays.
Microscope slide of radial surface of Spruce charcoal. Arrows point to location of axial tracheid and rays.