Stem in different vein (4)
I believe the answer is:
vine
'stem' is the definition.
The answer and definition can be both plants as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'different vein' is the wordplay.
'different' is an anagram indicator.
'vein' anagrammed gives 'VINE'.
'in' is the link.
Can you help me to learn more?
(Other definitions for vine that I've seen before include "Woody-stemmed climber" , "Climber - creeper" , "Plant bearing grapes" , "Fruiting climber" , "Climbing plant that needs support" .)