Sleuth Jane, not seeing river, finds wood (5)
I believe the answer is:
maple
'wood' is the definition.
(maple is a kind of wood)
'sleuth jane not seeing river' is the wordplay.
'sleuth jane' becomes 'Marple' (Miss Marple's first name is Jane).
'not seeing' indicates named letters should be taken away.
'river' becomes 'r' (abbreviation for river).
'marple' with 'r' taken out is 'MAPLE'.
'finds' acts as a link.
(Other definitions for maple that I've seen before include "Tree cultivated for its sap" , "Cathedral city in Devon" , "Emblematic tree of Canada" , "Hard light-coloured wood used for furniture" , "Canadian flag leaf" .)