Recalled hellebore essentially had a flared shape (4)
I believe the answer is:
bell
'a flared shape' is the definition.
'bell' can be an answer for 'shape' (bell shape is a kind of shape). I am not certain of the 'a flared' bit.
'recalled hellebore essentially' is the wordplay.
'recalled' is a reversal indicator (to recall can mean to bring something back).
'essentially' indicates a hidden word (essence can mean the inside of something).
'lleb' can be found hidden inside 'hellebore'.
'lleb' back-to-front is 'BELL'.
'had' is the link.
Can you help me to learn more?
(Other definitions for bell that I've seen before include "Boxing match signal" , "ring" , "Telephone call?" , "Metal instrument" , "Alternative to knocker" .)