If you wander down a trail in the woods on Vashon Island in Washington State you may see a strange sight. Up in a Douglas fir is a bike that has been in the tree for so long that the tree has grown around the bike and appears to be consuming it.
This bike in a tree is surrounded in mystery and legend and has resulted in a number of stories including a children’s book called Red Ranger Came Calling by Berkeley Breathed. There is a sad story of a young man who left his bike leaned up against this tree and then went off to fight in World War I and never returned, but this story seems to be fictional.
The story that seems to be the most accurate is about a man named Don Puz. When Don was a boy his father died when their house caught fire, so a lot of things were donated to him and his mother to help with the loss, one of which was this bike. The bike was a children’s bike and Don did not much like it, so he left it in the tree in an attempt to throw it away. Don grew up, left Vashon Island and forgot about the bike which was eventually consumed by the tree.
You may be wondering how a tree is able to grow around objects like this bike and still survive.
A tree grows much like any other organism by dividing and increasing its cells. Just under the layer of bark of trees there is a layer of dividing cells called cambium. The cambium produces two kinds of tissues called xylem and phloem. These cells act as the plants circulatory system with the phloem cells transporting sugar and other molecules produced by the plant, and the xylem cells transporting water and minerals and providing structure for the tree. When you look at a cross section of a tree you can see growth rings, which are sometimes used to estimate the age of a tree, and are the old xylem cells which are added on each year. As the tree grows and expands anything sitting next to or in the tree is slowly consumed as the tissue grows around it. The water and nutrients is passed around the object through the xylem and phloem cells without negatively affecting the health of the tree.