Crossword Genius

Mistress places importance on flowers (5-7)

Ross

I believe the answer is:

ladys-tresses

I'm a little stuck... Click here to teach me more about this clue!

'mistress places' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.

'importance on flowers' is the wordplay.
I cannot quite see how this works, but
'importance' could be 'stress' (stress is a kind of importance) and 'stress' is found within the answer.
This explanation may well be incorrect...

Can you help me to learn more?

I've seen this clue in The Times.
Want a hint initially instead of a full solution? Install my app