River Test perhaps associated with certain types of plant (10)
I believe the answer is:
industrial
'associated with certain types of plant' is the definition.
I can't judge whether this definition defines the answer.
'river test' is the wordplay.
'river' becomes 'indus' (Indian river).
'test' becomes 'trial' (synonyms).
'indus'+'trial'='INDUSTRIAL'
'perhaps' is the link.
Can you help me to learn more?
(Other definitions for industrial that I've seen before include "Relating to manufacture" , "fabricating things?" , "plants may be so described" , "Inlaid rust (anag.)" , "Rapid social changes, starting in Britain from about 1760" .)