Live Science has a story about the Wollemi pine.  Thought extinct, the Wollemi pine was “rediscovered” in 1994 by some hikers near Sydney, Australia.  Wollemia nobilis is pretty much unchanged since the Cretaceous Peiod.  A group of scientists from Australia, the US, and Italy have recently published the plant’s genome.  The genome gives insight into both its evolution and unique reproduction, which is mostly through self cloning.

The pine has 26 chromosomes — containing a staggering 12.2 billion base pairs. In comparison, humans have only around 3 billion base pairs. Despite the size of their genome, Wollemi pines are extremely low in genetic diversity, suggesting a bottleneck (when the population is reduced dramatically) some 10,000 to 26,000 years ago. 

Indeed, the plants do not exchange much genetic material. The remaining trees appear to reproduce mostly by cloning themselves through coppicing — in which suckers emerge from the base and become new trees.