It looks like Tenacetum parthenium ... English name Feverfew. It is said to be good for megrain. The leaves are very bitter.

I live in the USA- looks like Fleabane to me. A pretty weed of which I had a lot in my garden but for the last several years I don’t see anymore. I will find the scientific name.......Erigeron it is.

I did look at feverfew but that is more daisy-like with central yellow button and foliage is solid this has more delicate foliage similar to discus its an annual. It's also not fleabane it's medium height 2-2.5 ft.

It is Tanacetum parthenum, Hywel's correct - this particular one is the yellow leaved, double flowered form, I used to grow it myself when it was still called Chrysanthemum something or other. Image below, where they describe it as 'Feverfew, Double Golden'

https://www.midsummerherbs.com.au/product-page/feverfew-
double-golden

Its perennial actually, but doesn't always survive, especially in heavy soil if the weather is very wet in winter or its not cut back after flowering. Seeds itself prolifically, just like the standard form of Tanacetum.

I had the single and double flowers in my previous garden but I can't grow them here ... don't know why.

Odd, Hywel, I thought it popped up anywhere really... maybe your soil ph is difficult for it. Sadly, I've only got the single flowered version left now...

We have this, single, double and a yellow leaved form. It seed prolifically and some I leave and some I dispose of. Pretty and loved by hover-flies.

we also call it bachelors buttons as well as fever few. But it is Tanacetum parthenum.

I sometimes get it and some years not.

Bachelors buttons.... a Welsh lady I knew used that name for Kerria japonica... never heard it for feverfew though..

It's odd about common names Bamboo. My mother was Welsh and called Feverfew Bachelor's buttons. I've never heard that name for Kerria japonica .

Ha ha, Hywel... that's the trouble with common names, they vary round the UK, never mind round the world... the same lady I knew called Saponaria 'bouncing bet' but someone else I know calls it 'tumbling ted'... I remember answering a question once about what the OP called their 'quaking plant' because it 'quaked' and all the leaves kept falling off whenever the door opened or closed. Turned out to be Ficus benjamina, kept in a draughty spot and suffering from drought... Really, you might as well be saying Uncle Fred or cousin jane with common names.

I always prefer the botanical names Bamboo :)

Thank you everyone! it's sold now as Tanacetum parthenum "flora peno" a double must have spread from someone's​ garden long time ago on my estate. Does really look like a chrysanthemum i can see the confusion.