The most common and most likely answer to this crossword clue is the 14 letter word FORGET-ME-NOTS
I've seen this crossword clue in The Guardian
F
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Buddy explains!
The straight part
We know that "flowers" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case flowers = forget-me-nots.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.
What does FORGET-ME-NOTS mean?
FORGET-ME-NOTS noun- Any of the flowering plants of the genus Myosotis, mostly with a small five-petalled blue flower.
- A light tint of blue, the color of the flower.
- Any of various light-blue coloured lycaenid butterflies of the Asian and Australasian genus Catochrysops, especially Catochrysops strabo native to India and Southeast Asia.