Miniature variety of a plant or animal (5)
I believe the answer is:
dwarf
'miniature variety of a plant or animal' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for dwarf that I've seen before include "Stunt the growth of" , "Very small person or thing" , "Grumpy, e.g." , "One of the Snow White Seven?" , "Happy for one" .)