Polygala flowers share a keel shaped petal feature with gorse.
Despite this similarity they belong to different families. (Polygalaceae and Fabaceae for gorse).
Nature's fine artwork.
Decorative headgear on the keel, waving to attract insects. Bees use the appendage as a lever to open the flower up.
Wing petals protect the keel.
Polygala Unplugged.
Anthers and stigma unplugged. They curve into the shelter provided by the keel.
Gorse flowers for comparison.