I'm hoping it's just a new branch and not a parasitic plant, but it seemed very odd because of the location at the very base of the trunk. This is a relatively young tree that we bought 3 years ago as a required replacement by the city for a pine tree we removed.

Those are just new dogwood stems - no parasite or latent monster out to get anything.

It is quite common for trees (including dogwoods) to throw a sprout like this from dormant buds. It is a defense/survival mechanism against animal foraging/browsing, fire damage, and other unpleasantries that beset woody plants as they try to grow.

You should clip or break these off while they are little and tender, so the plant doesn't waste energy/resources on those stems.

ViburnumValley said:Those are just new dogwood stems - no parasite or latent monster out to get anything.

It is quite common for trees (including dogwoods) to throw a sprout like this from dormant buds. It is a defense/survival mechanism against animal foraging/browsing, fire damage, and other unpleasantries that beset woody plants as they try to grow.

You should clip or break these off while they are little and tender, so the plant doesn't waste energy/resources on those stems.

Ok, thanks. It's interesting that you mentioned defense against animal foraging, because on the opposite side, something (I think maybe a rabbit) chewed on the trunk about a year ago.

No fair hiding the best clues...

That would make perfect sense. Damage to xylem/phloem/cambium caused stress. Defense mechanism shouts "need more photosynthetic surfaces to recover from wound!" Response initiates growth from latent buds.

Plain as the sprouts on your dogwood...

Here's a pic of the damage after a year. I asked some Master Gardeners who were at the local hardware store about it when it first happened. They advised me to remove a couple of feet of the sod around the tree. The theory is that any animal inclined to chew on the trunk (in this case a small one like a rabbit since it was down low) would hesitate to cross the exposed area where they would be more visible to predators. I did that and it seems to have worked.