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 1954, Green began his botanical career as an assistant botanist at the Western Australian Herbarium and remained in that position until 1958. During his last year, he served as a botanical advisor to phytochemical surveys in the southwest.