The most common and most likely answer to this crossword clue is the 8 letter word LARKSPUR
I've seen this crossword clue in The Times
L
A
R
K
S
P
U
R
More clues leading to the result LARKSPUR
- Flower birds turn up on river
- Birds show pleasure endlessly, finding flowering plant
- It’s a bit of fun to encourage flowering plant
- Mess about with branch in flower
- Birds turned up on river to see plant
- Songbird settled beside egg on delphinium
- Early birds returning, beginning to rip up delphinium plant
- Then are cats heard to soar in 14 down?
- Plant egg behind bird
- Birds half-destroyed purple plant
Buddy explains!

The straight part
We know that "Flower" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case flower = larkspur.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 LARKSPUR mean?
LARKSPUR noun- Any plant of the genera Delphinium or Consolida
- In particular, a tall robust flowering plant with many purplish-blue flowers, Delphinium glaucum.