Balsam Blisters

One of the common coniferous trees on the property is the balsam fir (Abies balsamea). If you live in the northeastern U.S. and have had a live Christmas tree, this is probably what it was.

If you look closely at the bark of a balsam fir, you may notice that it’s dotted with big round bumps that give a little when you put pressure on them.

Press hard enough, and they’ll burst, squirting sap-like resin all over your hand so that you spend the rest of your walk sticky and smelling like Christmas. This is oddly satisfying, like popping a pimple.

I haven’t been able to find any information on why, exactly, the tree produces these resin blisters. Does anyone know? Also, have any of you ever tried the balsam fir motor boat trick? It’s on my “to-do” list for sometime when I’m on a wander near one of our lakes.

2 replies on “Balsam Blisters”

Hi Rebecca! Nice observation! Generally, these blisters have resin or pitch that is used to combat against insect infestation, such as bark beetles. When beetles try to pop them they get stuck in the resin and it drys up quickly. Like Jurassic Park, except no dinosaurs! I’m no expert on this tree species in particular, but I think its a good hypothesis given that its a widespread defense strategy in some conifers. Maybe you should think about conducting an experiment? Have you seen any bugs trapped in it?


Comments = love!

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s