Australians use sally for eucalypts and acacias that resemble willows.
Nilson, Timber trees of New South Wales, 1884; also later.

sallow 1. a plant of the genus Salix, willows.
Old word, 14th C. or earlier, OHG and OE, many variants; sally is common in Ireland. 'Salwes' in Chaucer. In poetry by Shelley, Tennyson and Cowper as well as Yeats.

No particular willow species is indicated.

All of the above from the OED.