In Mali, a natural climber (5)
I believe the answer is:
liana
'climber' is the definition.
(climbing plant)
'in mali a natural' is the wordplay.
'in' says the answer is hidden in the clue.
'LIANA' is hidden within 'mali a natural'.
(Other definitions for liana that I've seen before include "Rainforest climber" , "Woody climbing (usually tropical) plant" , "Tropical vine" , "Jungle creeper" , "Climbing-plant" .)