Periodical trouble working over in plant (8)
I believe the answer is:
magnolia
'in plant' is the definition.
'magnolia' can be an answer for 'plant' (I've seen this before). I'm not sure about the 'in' bit.
'periodical trouble working over' is the wordplay.
'periodical' becomes 'mag' (abbreviation for magazine).
'trouble' becomes 'ail' ('ail' can be a synonym of 'trouble').
'working' becomes 'on'.
'over' is a reversal indicator.
'ail'+'on'='ailon'
'ailon' in reverse letter order is 'nolia'.
'mag'+'nolia'='MAGNOLIA'
Can you help me to learn more?
(Other definitions for magnolia that I've seen before include "Tree with creamy-white flowers" , "Fragrant bloom and popular paint colour" , "Whitish-flowered tree" , "Tree; pale creamy-white" , "Early-blooming tree; off-white colour" .)