Often tables and chairs have little burrs that can catch your dress.
The burrs on each head of the burdock plant tend to catch on the fur of passing animals which helps the seeds spread.
The Minnesota cedar logs are left with their natural marks made from nature and could include bug trails and insect tracks, checking, fire scars, elk rubs, burrs or burls.
If you allow your dog to run the fields, as most Welshes love to do, be sure to brush burrs and other debris out of his coat upon his return.
Turning now to outgrowths of a woody nature, the well-known burrs or knaurs, so common on elms and other trees are cases in point.