Coming up in winter, a deciduous tree (5)
I believe the answer is:
cedar
'tree' is the definition.
(cedar is a kind of tree)
'coming up in winter a deciduous' is the wordplay.
'coming up' says the letters should be written in reverse.
'in' says the answer is hidden in the clue.
'radec' is hidden in the letters of 'winter a deciduous'.
'radec' back-to-front is 'CEDAR'.
(Other definitions for cedar that I've seen before include "Tall conifer" , "may have needles?" , "Raced around a mighty tree" , "representative of Lebanon?" , "Raced around a great hardwood tree" .)