Banksia is a genus of plants that occur in Australia and New Guinea.  Most are found in Western Australia, including the Banksia Grandis, the species that generates these large seed pods.  These cones (lower left) can be from 4 to 16 inches long.  Once the golden yellow or red flowers fall off, the cone matures on the tree and the seeds develop.  Often it is the heat of a forest fire that causes the seed holes to burst open and release their seeds.