Bamboo stem (4)
I believe the answer is:
cane
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">bamboo stem</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 cane that I've seen before include "Walking stick; punish" , "Slender stem of bamboo etc" , "A stick to lean on" , "Birch" , "Eg, bamboo; punish" .)