Disease on unknown plant (blueberry?)

We just moved to a property in Chilliwack. There are three or four bushes (maybe blueberries?) on the property that have strange black caterpillar-like growths on their stems. I bought two new lovely blueberry plants and I don’t want them infected by whatever this might be (they are safely on my porch in pots right now). Does anybody know what these plants are and what’s affecting them?

 

I had hoped someone more knowledgeable than me might have answered your post but now that it's about to drop off the list of current posts, I will do my best.
If others disagree, hopefully they'll chime in.

To my eye, the growths on the plants pictured look fungal to me - perhaps black knot.
The plant in the left-hand photo seems to have died and new growth is coming from the base.
I don't think they are blueberries and since black knot only affects shrubs in the genus Prunus such as cherries and plums, your new blueberry plants would not be susceptible.
Although the fungus would be unlikely to infect your new blueberries, the spores it releases in the spring will potentially spread the disease to other Prunus species in the area.
Because black knot can spread and is difficult treat, I would get rid of the diseased plants and either burn the branches or dispose of them in an appropriate dump site.

 

Thanks so much Margot! Mysteries abound on this new property of mine. There is a large nursery nearby so I might double check with them but my first instinct was to get rid of the plants as well.

 

Yes, agreed re: black knot.