The Collaborative International Dictionary
Brier \Bri"er\, n.
the white heath Erica arborea.
--RHUD.-
a smoking pipe made of the root of the brier[1].
Note: Brierroot seems to have been used formerly as a term meaning root of the Smilax laurifolia and is now defined as root of the Erica arborea. Not clear when this changed. -- PJC.
briarwood \briarwood\ n. wood from the hard woody root of the briar Erica arborea; used to make tobacco pipes.
Syn: brierwood.
brierwood \bri"er*wood`\ n. 1. wood from the hard woody root of the briar Erica arborea; it is used to make tobacco pipes. See also 2nd brier and brier root.
Syn: briarwood.
briarroot \briarroot\ n. the hard woody root of the briar Erica arborea. [Also spelled brierroot.]
Wikipedia
Erica arborea (tree heath) is a species of flowering plant (angiosperms) in the heather family, Ericaceae. There are disjunct populations in Africa including the Ethiopian Highlands, the mountains of Ruwenzori and the Cameroon Mountains. In Africa it is normally referred to as giant heather. It is native to the maquis shrublands surrounding the Mediterranean Basin and west to Portugal and the Canary and Madeira Islands. Naturalised populations occur in south-eastern Australia.