The most common and most likely answer to this crossword clue is the 8 letter word PERIANTH
P
E
R
I
A
N
T
H
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The straight part
We know that "Part of flower" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case part of flower = perianth.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.
Crossword Answer definitions
PERIANTH noun- The sterile parts of a flower; collectively, the sepals and petals (or tepals).
- The sterile, tubelike tissue that surrounds the female reproductive structure in a leafy liverwort.