Welcome back to Ask a Naturalist, your own personal Google for information on all things natural on PEI. Jeff Matheson sent me this wonderful photo of blue resin on the side of a spruce tree and was curious about the unusual colour. Let’s take a look!   First, it’s useful to know the difference between sap and resin (sometimes called pitch). All trees have sap, and it’s analogous to blood in animals: it carries water, sugar, nutrients, minerals, and hormones throughout the tr