Sonchus ...

[BubikolRamios]

Note very fat/thick stem. Loc.: NW Slovenia.
http://agrozoo.net/jsp/Galery_one_image ... 24148f2c4f

Not Picris hieracioides (have/can have top yellow, bottom pink/red petals), I think.

[Anagallis]

Sonchus asper?

[BubikolRamios]

Ok, bad or no good leaf image. But nothing like that: http://agrozoo.net/jsp/Galery_one_image ... a360c123c5

Maybe, according to this image leaf, oleraceus: http://agrozoo.net/jsp/Galery_one_image ... 937dae5647
but the stem on image from OP is really thick, not fertilized ground.
Here what I have currently:

[Anagallis]

Sonchus' leaf shape is very variable. It's definitely not S. oleraceus which has pointed auricles.

[BubikolRamios]

https://uses.plantnet-project.org/e/ind ... ew_desktop

it appears red stem and/or red central leaf vein & leaf edge is an option (as at OP).

[BubikolRamios]

Sonchus' leaf shape is very variable. It's definitely not S. oleraceus which has pointed auricles.

will check more about that, at actual plant tommorow ...

[Anagallis]

The plant shown on that page is Sonchus asper. Pay attention to the shape of the auricles: S. asp. has round auricles that cling to the stem. The auricles of S. ol. point past the stem in the opposite direction of the leaf blade, not clinging to the stem.

[BubikolRamios]

Here is the thing:
1,2 - top, bottom leaf of OP image, all inbetween the same shape.
3. Another find that I think is S. asper, all leaves on plant same shape.

https://postimg.cc/r0y2Hbhv

?