This interesting plant is Cryptostylis erecta, the Bonnet Orchid" or the "Tartan Tongue Orchid".
This is the third in a series I have promised to write, of the 4 species of Tongue Orchids which grow in this region. Click on each image to see the flower in its full glory!!!The "Bonnet" is the Labellum, but it is held upright, quite unlike the Large Tongue Orchid about which I wrote recently.
The labellum is not recurved (as the previous one was), but is "very broad, deeply concave, forming a hood" (RBG Sydney PlantNET). Hence the name Bonnet Orchid.
This flower has some structural similarities to the "Leafless (or Furry) Tongue Orchid". At least that one also holds the labellum upright, but it is recurved laterally (rolled back on the sides). Also, as the second name tells you, that flower is totally hairy. unlike this one. It is also a leafless plant, whereas this species has a prominent upright leaf, with a green reverse.
The main "common" factor these "Tongue Orchids" have is the single dominant petal which is the "labellum" and all others are reduced to thin rolled structures, once mature.
I actually like the alternative name, Tartan Orchid, because of the colourations which remind me of some of the more subtle Tartans. It lacks a weave in the pattern, though.
This last photo shows nicely the other buds which have just started to open. If you look closely at the far left top bud, you can see that its dorsal sepal is just starting to separate off from the rest of the flower. Once the sepals and the lateral petals open, they curl around very tightly (lateral curl - keeping the full length), to become the "perches" upon which the male wasps land, before "assuming the position" on the flower. I first wrote about that phenomenon, on this particular species, three years ago. This curling up of the other sepals and petals is a very strange arrangement, when you consider that the labellum is such a fulsome petal - to which all the others become subservient, once they open. This is a very different arrangement from the Sun Orchids, for example, in which all the sepals and petals are virtually "equal" in size and function.
Colin, reported to me the other day that he had found (at Marlo, Victoria) "3 of the tongue orchids species in flower. The large, the furred and the bonnet. All in an area 10m square."
That's pretty good going. Those are the three species I have reported upon so far.
You may see Colin's full page of his excellent photos of this species by clicking here.