Said to be usin' oars made from native tree (5)
I believe the answer is:
rowan
'tree' is the definition.
(type of tree)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for rowan that I've seen before include "-- Williams, theologian" , "Red-berried tree" , "Tree with orange-red berry-like fruits" , "ash native to mountain regions" , "The mountain ash tree" .)