ID on this NOXIOUS WEED from Australia

Can anyone tell me which noxious Weed it is ?

This Picture shows the Bud, Flower and seed pod.

 

Might this be Mexican prickly poppy (Argemone mexicana) or a relative of it?
A. munita?

 

The white-flowered species widely naturalised in Australia is Argemone ochroleuca

See this link - http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=gn&name=Argemone

 

Intersting key! From it:

I'd say those two colours are the same?

 

You are right, it does seem a bit weak. But the key leads do give two other differentiating characters. Some of our Australian butter is quite a rich yellow and maybe that's what the writer had in mind.

I seem to recall that our identifications of the species naturalised here were based on a 1960s revision of the genus by Ownbey. See also his Flora of North America treatment at http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=102532

 

Depends on how good the butter is...

 

Thanks Tony,

It is indeed a Argemone ochroleuca.
Fancy that, It took an Aussie to find it.
And one who only signed up today as well.


Thanks mate.

I did have a few more Pictures but they won't be needed now.

 

Butter yellow is a deeper yellow than cream to pale yellow. The latter could also be stated as yellowish, rather than definite yellow. The dairy products comparisons cover it, that is butter-colored rather than cream.