The most common and most likely answer to this crossword clue is the 8 letter word NARCISSI
I've seen this crossword clue in The Guardian
N
A
R
C
I
S
S
I
More clues leading to the result NARCISSI
- Plants in island thus smuggled from the east
- For transplant, scan iris and other flowers
- Flowers, ones thus having managed to climb
- US drug cops capture one from Mexico — yes, with plants
- An iris starts to seed cultivated hybrid fowers
- Son thus goes into country, returning for flowers
- Haphazardly scan iris and other flowers
- Has life in Cairns destroyed flowers?
Buddy explains!

The straight part
We know that "plants /plants" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case plants /plants = narcissi.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 NARCISSI mean?
NARCISSI noun- Any of several bulbous flowering plants, of the genus Narcissus, having white or yellow cup- or trumpet-shaped flowers, notably the daffodil
- A beautiful young man, like the mythological Greek Narcissus