This is my drawing of a shrub I studied for two years. Its name is Dillwynia sieberi. The drawing shows an inflorescence. The flowers are pollinated by bees. Marked "a" on the drawing is the chamber formed by two ‘keel’ petals housing pistil and stamens. Marked "b" is the location of nectaries and marked "c" is one of the ‘wing’ petals. When a bee lands on the flower in search of nectar it pushes the 'wing' petals which open up the chamber to expose pistil and stamens for pollination.
I am growing a Dillwynia plant in a shallow pot in my garden, but I don't think this species makes good bonsai material.