Succulent plants (5)
'succulent plants' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for cacti that I've seen before include "Spiny desert plants" , "growing group" , "Desert features" , "Spiny succulents" , "They're decidedly prickly" .)
'succulent plants' is the definition.
(I've seen this in another clue)
This is all the clue.
(Another definition for aloes that I've seen is " purgative drug".)