Mushrooms and toadstools (5)
I believe the answer is:
fungi
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">mushrooms and toadstools</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 fungi that I've seen before include "Spore-producing organisms" , "Toadstools, say" , "Eg, toadstools" , "Yeasts, moulds, mushrooms etc" , "life in woodland?" .)