The passion flower Passiflora spp is associated with the Passion of Christ because of the shape of its flowers. Wikipedia explains the Christian symbolism in handy dot points. You often see passion flowers used as a motif in churches in Holy Week, particularly in embroidered altar cloths and priestly regalia. Sadly this one, which is the common commercial fruit producing species P. edulis, is an escapee, growing in the bush on Brown Mountain in New South Wales. It is native to South America.