Succulents (5)
(Another definition for agaves that I've seen is " Spiky plants".)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">succulents</span>' is the definition.<br/ ><span class="explanation-format__explanation">(cactus is a kind of succulent)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for cacti that I've seen before include "Desert features" , "They store water" , "Spiny succulent plants" , "Prickly plants" , "Spiky plants found in deserts" .)