The most common and most likely answer to this crossword clue is the 7 plus 8 letter word EVENING PRIMROSE
I've seen this crossword clue in Financial Times
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More clues leading to the result EVENING PRIMROSE
- Medicinal plant cultivated in vigneron's empire
- Having drunk limitless wine, ailing emperor's given herbal remedy
- Regimen is proven to regenerate flower
- Herbal remedy still popular with grand prissy girl
- Its oil is refreshing, improving and serene
- Regimen is proven to generate a flower
- One Pole following straightforward German writing about border flower
- Medicinal plant cultivated in vigneron’s empire
- Pressing a flower that opens late
- Plant genre improves in process
Buddy explains!
The straight part
We know that "Its oil is refreshing" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case its oil is refreshing = evening primrose.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.