Agaricus perobscurus
... that toxic puffball Agaricus praeclaresquamosus can be distinguished from its close relative Agaricus perobscurus by a stipe base which turns yellow immediately when injured?
... that toxic <a href="./Puffball" id="mwEhM" rel="mw:WikiLink" title="Puffball">puffball</a> <i id="mwEhQ"><a class="mw-redirect" href="./Agaricus_praeclaresquamosus" id="mwEhU" rel="mw:WikiLink" title="Agaricus praeclaresquamosus">Agaricus praeclaresquamosus</a></i> can be distinguished from its close relative <i id="mwEhY"><b id="mwEhc"><a href="./Agaricus_perobscurus" id="mwEhg" rel="mw:WikiLink" title="Agaricus perobscurus">Agaricus perobscurus</a></b></i> by a <a href="./Stipe_(mycology)" id="mwEhk" rel="mw:WikiLink" title="Stipe (mycology)">stipe</a> base which turns <a href="./Yellow" id="mwEho" rel="mw:WikiLink" title="Yellow">yellow</a> immediately when injured?