Container with a lentil mistaken for another plant (10)
I believe the answer is:
potentilla
'another 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?
'container with a lentil mistaken' is the wordplay.
'container' becomes 'pot' (pot is a kind of container).
'with' means one lot of letters go next to another.
'mistaken' indicates an anagram.
'a'+'lentil'='alentil'
'alentil' with letters rearranged gives 'entilla'.
'pot'+'entilla'='POTENTILLA'
'for' acts as a link.
(Other definitions for potentilla that I've seen before include "plant" , "Small shrub" , "Cinquefoil genus" .)