Area yielded plant of the aloe family (5)
I believe the answer is:
agave
'plant of the aloe family' is the definition.
(agave is an aloe plant)
'area yielded' is the wordplay.
'area' becomes 'a' (maths abbreviation).
'yielded' becomes 'gave' ('give' can be a synonym of 'yield').
'a'+'gave'='AGAVE'
(Other definitions for agave that I've seen before include "plant in Mexico" , "Plant, source of sisal" , "Succulent plant" , "Tropical plant" , "native growing up in tropical America" .)