Annual rings clearly observed in cross-section of tree trunk

Gymnosperm wood is comprised mostly of tracheids

This cross-section of a gymnosperm tree trunk clearly shows annual rings but the interfaces between summer and spring woods of the rings is due to smaller and more compact tracheids in the summer wood. Almost all of the wood is comprised of tracheids, giving a relatively uniform appearance to the wood.

While xylem rays are present, they are mostly uniseriate, i.e. one cell in width, and therefore are too small to be evident in this photograph. Uniseriate and biseriate rays are characteristic of gymnosperm wood.