This piece of conifer wood is made up of primarily tracheids.  This is a cross section.

BLUE ARROWS - Between A and B is one growth increment.  Between B and C is another growth increment.

RED ARROWS   - Are resign ducts which are enlarged parenchyma cells.

They start at the beginning of the increment as thin walled tracheids and towards the end or summer wood, you see they are thick walled tracheids.

Angiosperms do not have tracheids, they have vessels.

BLUE ARROWS - On this maple sample they point to vessels. 

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 John A. Keslick, Jr.