Large plant beginning to bottle four different types of claret (6)
I believe the answer is:
baobab
'large plant' is the definition.
The definition and answer can be both plants as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for baobab that I've seen before include "Tree indigenous to Africa and Australia" , "African or Australian tree with very thick trunk" , "Gigantic tropical tree with very thick trunk" , "Exotic tree" , "Monkey-bread tree" .)