Many kinds of willows can be grown to produce rods for basketry, by continuously cropping, or coppicing the new growth off stumps. But most of those grown commercially are of the Common osier, Salix viminalis, which has been selected because of its long, supple twigs.
Almost certainly an archaeophyte in Britain, or if it is autochthonous it is not autochthonous to anywhere in the south-west.
At Trebrown Nurseries we maintain our own registered seed stands on Trebrown Farm, which remain the only seed stand registered in Cornwall. Salix viminalis is not a FRM controlled species, but is certified under the voluntary FRM scheme.