All the stages ......

..... of a Spiny Sowthistle.
This plant grows everywhere from tropical to arid, farm crops to parks and gardens. The plant produces thousands of seeds, as many as 25,000 per plant.
The flower is similar to a dandelion in shape, colour and behaviour ...... bright yellow, opening up when the sun shines and then closing again at night. Just like the dandelion the Sowthistle has a puffy seed head, with the seed 'parachutes' blowing in the wind when ready.
Sowthistles will always have several flowers per stalk .... dandelions will only ever have one flower per stalk.

In almost every walk I take in Pollok Park I find something growing that I don't immediately recognise. Google is a veritable treasure chest of info.