Pseudotsuga uniseriate rays in secondary xylem.

 

This detail shows several rays emerging at right angles to the longitudinally orientated secondary vascular tissue, which in the case of Pseudotsuga, is composed of tracheids, fibres and parenchymatic elements. Note the rays are uniseriate, that is, they are one cell in width. The detail to the right, illustrates a multiseriate ray. Here the ray contains a resin duct (arrow) as well.