Order for nice tree (7)
I believe the answer is:
conifer
'tree' is the definition.
(I know that conifer is a type of gymnospermous tree)
'order for nice' is the wordplay.
'order' is an anagram indicator.
'for'+'nice'='fornice'
'fornice' is an anagram of 'CONIFER'.
(Other definitions for conifer that I've seen before include "The tree doesn't lose its leaves" , "Type of tree" , "one branching out" , "The tree keeps its leaves" , "Evergreen tree" .)