Thanks to Anne Huntington for sending along this photo. The picture was taken (in Wayne, Maine) after a heavy rain that was followed by a cold snap. What’s going on with this tree?
Answer
The icicle was formed from water that had pooled in a cavity of a tree. The color was caused by tannins that leached from the wood (and other material if the cavity was open to the sky) and accumulated in the water. The heavy rain caused the water to overflow the cavity and run down the tree trunk. An additional clue from the photo: It looks like the icicle is in a slightly rotten seam of the tree, a sign the tree has some internal rot, further supporting the presence of a cavity elsewhere in the tree.
This week’s contest winner was Rita Klaus