A plant with a slender woody stem bearing stout prickles; especially, species of Rosa, Rubus, and Smilax.

Fig.: Anything sharp or unpleasant to the feelings.

The wood from the burl found at the base of the White Heath Tree used in pipe making. Found only in the Mediterranean Sea area.

Eurasian rose with prickly stems and fragrant leaves and bright pink flowers followed by scarlet hips

a very prickly woody vine of the eastern United States growing in tangled masses having tough round stems with shiny leathery leaves and small greenish flowers followed by clusters of inedible shiny black berries

evergreen treelike Mediterranean shrub having fragrant white flowers in large terminal panicles and hard woody roots used to make tobacco pipes

a pipe made from the root (briarroot) of the tree heath

a bramble, or thorned stem of some sort, so I'd imagine it's some kind of thorny vine to which he refers

King of pipes. From the wood of the white heath.

The name is a corruption of the French word "bruyere", or heath tree, a low shrub found throughout Europe, though mainly around the Mediterranean. The true briar is only made out of the very hard, dry root of the mature shrub which may be anything up to 250 years old.