Sydney's Royal Botanic Gardens occupy a lovely parcel of harbor-side land, right alongside Australia's biggest downtown district. On weekdays, the park fills with joggers, walkers and sandwich-eating hoards picnicking among its lush plantings. But one of the garden's 45,000 plants is strictly off-limits to the wandering public. The Wollemi Pine, an odd and scruffy looking specimen, is tightly encased in a 15 foot high steel cage, well out of reach. A sign nearby explains why; the tree is among the rarest on earth.
In fact, until 11 years ago, the Wollemi Pine (