Date with X-man - plus one is a plant! (9)
I believe the answer is:
dandelion
'one is a plant' is the definition.
(I know that dandelion is a type of herb)
'date with x-man plus' is the wordplay.
I cannot quite see how this works, but
'date' could be 'd' (common abbreviation eg in DOB, date of birth) and 'd' is present in the answer.
'with' could be 'and' and 'and' is found in the answer.
'man' could be 'lion' and 'lion' is found within the answer.
A single letter 'e' remains which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for dandelion that I've seen before include "Common yellow-flowered weed" , "Yellow weed" , "It has a bright yellow flower followed by a fluffy seed ball" , "Weed with deeply incised leaves" , "salad leaves" .)