Green began his botanical career in 1954 as assistant botanist in the Western Australian Herbarium.
He remained in that position until 1958, in his final year serving as botanical adviser to phytochemical surveys in the southwest.
In 1970 he moved to Ontario, Canada, taking up a post as professor at the Laurentian University.
In 1975, Green returned to Australia, taking on the post of curator to the Western Australian Herbarium.
Green has published a number of plant taxa, among which the following are still current: He was also collector of the type specimen of Eucalyptus dolichorhyncha.