Primula veris

Cowslip. Sweetly perfumed and widespread European plant, its natural habitat extends throughout large areas of eastern and western Europe, Iran, Siberia, Turkey, the upper Amur valley northeast of Mongolia, finally almost reaching the Pacific coast. A favourite in the British woodlands.

The plants grow well in well-drained neutral grassy fields or on banks, more open sites than usual for primroses and also in light woodland.  Smaller in the open.  Don't think you can grow them here in grass unless it is very thin, weedy and damp. Our grasses are smotherers if it is moist. I find it very tolerant and it seeds in cracks and crannies round the paving in our light woodland area. Once flowering it will set seed and if you don't hoe or have huge plants everywhere, babies will appear and clumps form. Heaven.

They were  fantastic in the UK on some of the motorway banks, great hills full of yellow in full sun, but then they have damper weather than we do!

If you collect the seed and sow, it will take a while, but keep them cool.