Flexible willow twigs (6)
I believe the answer is:
osiers
'flexible willow twigs' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for osiers that I've seen before include "Willow twigs used in basket-making" , "Kind of willows for weaving - Rosie's?" , "Roses I find with flexible willow twigs" , "Flexible twigs used in basketwork" , "Willow twigs used in basket-work" .)