Those in the leaves of tangled vines? (5)
I believe the answer is:
veins
'those in the leaves' is the definition.
The definition suggests an adverb but the answer is not.
'tangled vines?' is the wordplay.
'tangled' indicates anagramming the letters.
'vines' with letters rearranged gives 'VEINS'.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for veins that I've seen before include "Characteristic styles" , "Circulation aids" , "Blood vessels" , "Layers of ore" .)