### Clue: Ponder over trace of ergot on popular plant (7)
### Answer: MULLEIN 
 ### Explanation: Definition: plant
 MULL(to ponder/to think about deeply and at length) **placed above**(over, in a down clue) **1st letter of**(trace of) "ergot"**placed above**(on, in a down clue) IN(popular/in fashion).