It grows in some parts of Ireland (3)
I believe the answer is:
fir
'it grows in' is the definition.
The definition suggests a singular noun which matches the answer.
'parts of ireland' is the wordplay.
'parts' indicates the answer is hidden within the clue (I've seen 'part' mean this).
'FIR' can be found hidden inside 'of ireland'.
'some' acts as a link.
Can you help me to learn more?
(Other definitions for fir that I've seen before include "Coniferous tree" , "Tree for Irishmen" , "Kind of cone-bearing tree" , "Scots pine" , "Evergreen tree for Irish men?" .)