Yellow Blossom?

I don't know much about plants, gardening and all that sort of thing. Hence the question mark over blossom.

I tend to subscribe to the view expressed by some of concreting the lot and painting it green.

However in search of today's blip I took a quick stroll in the garden and saw this obliging thing whatever it is.

It well might be a weed. Oh well, publish and be damned!