Clue: Wild Erica2,3 Arborea1,2,3 (5)
Answer: BRIAR
Explanation: Wild Erica2,3 Arborea1,2,3 (5)
An anagram ('wild') of RI ('e**RI**ca2,3) plus ARB ('**ARB**orea1,2,3), The wood of Erica arborea, tree heath, is known as briar root, and is used to make briar pipes. In the original, the figures are superscripts.