As the main flush of European gorse flowers fade in May and June so July brings the flowers to western gorse (Ulex gallii). Western gorse will continue flowering until October by which time the European gorse will start to bear blossom prior to the main flowering in the spring. This succession gives rise to the belief that gorse flowers continuously. Gorse may well flower almost continuously throughout the year but that is because there are, in fact, three species flowering at different times.
There are other differences between western and European gorse than flower times. The flower of western gorse is smaller and more slender being a paler yellow and lacking the coconut fragrance of its cousin. The spines on western gorse are akin to razor wire whereas European gorse is just very prickly! There are other minor differences for the specialist botanist to ponder too. The two species do grow side by side and do hybridise just to complicate matters. However, whilst the southern heaths of Purbeck are dominated by European gorse so around Poole and further north one will encounter more western gorse.