The other possibility was Brachyscome obovata, which according to Vicflora has 20-29 green bracts surrounding the flower head. Brachyscome graminea has 15-20 green bracts around the flower head.
Thanks Betty, I was having some trouble trying to distinguish between those two species. In the end I used the paper by Short (2014) and to some extent I relied on leaf width and shape and ecological factors such as habitat and altitude of the sighting. I should have looked for some seeds, but it was getting very hot and it slipped my mind. If you don’t have it the Short paper is available as a PDF, full reference being: Short PS (2014) A taxonomic review of Brachyscome Cass. s.lat. (Asteraceae: Astereae), including descriptions of a new genus, Roebuckia, new species and new infraspecific taxa. Journal of the Adelaide Botanic Gardens 28 (2014) 1–219.