Taro dish nibbled initially by a lot of agents with sodium in a tree (9)

'sodium in a tree' is the definition.
The definition and answer can be both plants as well as being singular nouns.
Maybe you can see a link between them that I can't see?

'taro dish nibbled initially by a lot of agents' is the wordplay.
I cannot quite understand how this works, but
'dish' could be 'poi' (poi is a kind of dish) and 'poi' is found in the answer.
'a' could be 'an' and 'an' is found within the answer.
'lot' could be 'c' and 'c' is present in the answer.
The remaining letters 'nia' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).

'with' acts as a link.

Can you help me to learn more?