Smooth-barked tree (5)
I believe the answer is:
beech
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">smooth-barked tree</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for beech that I've seen before include "It has branches" , "Common forest tree" , "Timber tree" , "Copper or silver tree" , "Tree of Fagus genus" .)