Minor branch’s special apparatus (5)
I believe the answer is:
sprig
'minor branch's' is the definition.
'sprig' can be an answer for 'branch's' (sprig is a kind of branch). I'm not sure about the 'minor' bit.
'special apparatus' is the wordplay.
'special' becomes 'sp' (abbreviation).
'apparatus' becomes 'rig' (I've seen this before).
'sp'+'rig'='SPRIG'
Can you help me to learn more?
(Other definitions for sprig that I've seen before include "Shoot - twig" , "Small branch or shoot" , "Tree shoot; headless nail" , "Spray - youngster" , "Small spray of leaves or flowers" .)