Ligneous plant (4)
I believe the answer is:
tree
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">ligneous plant</span>' is the definition.<br/ ><span class="explanation-format__explanation">(tree is a kind of ligneous plant)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for tree that I've seen before include "Eg, a baobab" , "Hazel for instance" , "Large woody plant (4)" , "Big plant" , "eg Lime" .)