This post is aimed at some Yankee (& South American, & European) readers who won’t be familiar with Australian flowers.
These are hanging in our back yard, from a gum tree. The “bud” opens out to be a few flowers, via the smaller, red buds. These shed the little plastic-looking red cap to reveal the (yellow) flower proper. The main bud is a bit larger than an inch across, & the (European) bee should give you a good idea about the scale of the flowers.
These are quite moderate. There are other (introduced) gum trees in the area which flower about January, a single huge (4-6 inches across) bright-red flower from a single bud.
No, this isn’t the oddest Aussie flower, not to some degree. (-: