Can someone identify this plant/weed?

[artful bodger]

This is a plant I have noticed in the last year near where I live in Southern Tassie in a relatively confined space so far but it is spreading.
I have looked at all the "Problem Weeds" on the relevant state government department websites but have drawn a blank.
I have lived in this area for 30+ years and have never seen it before.
Perhaps it is not a problem weed, maybe someone has thrown garden refuse over the side of the road and it has taken off. It is a road that lends itself to illegal dumping as the sides are steep and there are many places that are out of view.
The plants are about 450mm tall.
Hoping there is a greenthumb out there who may know.
Thanks in advance
The weed.JPG

[Wrongwayfirst]

It’s not what you know it’s who you know, I have a “friend” who is very good with weeds

pretty sure it is caper spurge (Euphorbia Lathyris) and yes it is a noxious weed in Tassie

39A86C6B-3372-4BB1-B190-FE1C16188260.jpeg

cheers wrongwayfirst

[artful bodger]

Thank you Wrongwayfirst. Looks like you nailed it.