Heather genus (5)
I believe the answer is:
erica
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">heather genus</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for erica that I've seen before include "hardy shrub" , "Plant of the heath genus" , "Moorland plant, girl's name" , "Heather, for instance" , "growing up on the moors" .)