There are a number of different plants with a complex ‘dandelion’ like flower and they can be quite confusing at first, indeed they can be quite confusing to even experienced botanists! The secret (if there is one) is to look beyond the flower at the plant itself.
Cat’s-ear (Hypochaeris radicata) gets its name from little ‘ear-shaped’ leaflets that can be found on the otherwise smooth stems and this is the defining factor. The overall ‘look’ of this plant is different from many of its relatives when you get to know it; it is totally smooth and hairless whereas many others in the family are very scruffy and hairy, even prickly. A single plant will have multiple stems and each stem will have multiple flowers. As I say, given the similarity of the flowers in this group you need to look at the leaves and stems if you want to tell them apart.
Cat’s-ear is in flower from June onwards until the frosts put an end to them. It is a widespread plant, often abundant where they occur, and you can find them just about anywhere; on roadside verges, in hedgerows, in meadows and grassland, on sea cliffs, sand dunes, indeed anywhere as long as the soil is not too chalky.