Poison sumac in back yard safe removal
Good news! The shrub in your photograph is not poison sumac. The reddish twigs and the shapes of the flower bud and leaves lead me to believe it could in fact be a member of the dogwood family. Much better!
If you are able to take a photo of the overall shape of the plant so we can judge its habit and size, as well as a photo of the opened flower, we can do our best to more closely identify your plant. For the time being, you can cancel the call to the professionals.
The last photo in your series of the tree trunk seems to be unrelated to this shrub. Hope that helps!