Rosie broke tree (5)
I believe the answer is:
osier
'tree' is the definition.
(I know that osier is a type of osier)
'rosie broke' is the wordplay.
'broke' indicates anagramming the letters.
'rosie' with letters rearranged gives 'OSIER'.
(Other definitions for osier that I've seen before include "Basket material" , "Basket-maker" , "Willow for basket making" , "Willow used in weaving" , "Willow growing shoots used in basketwork" .)