Cross-field pitting referres to the pores between the ray parenchyma cells and the vertical tracheids. The pores between the ray tracheids, if the
ray tracheids are present, are different. Cross-field pitting is somewhat variable within a growth ring so it is best to consider the first two or
three rows of early wood.
Abies (True Fir)
Pseudotsuga (Douglas Fir)