Palm tree native to Madagascar whose large leaves yield a fibre used for weaving (6)
I believe the answer is:
raffia
(Other definitions for raffia that I've seen before include "Woven palm tree fibre" , "Palm fibre for e.g. baskets" , "Tropical palm leaf fibres used to make mats etc" , "Type of palm tree" , "Fibre for tying and weaving" .)