Selaginella and 400 million years of separation.

Selaginella (spikemoss) is an enigma in the plant kingdom. Although a fascination to botanists at the turn of the twentieth century, members of this genus are unremarkable in appearance, never flower, and are of no agronomic value. However, members of this genus are relicts from ancient times, and one has to marvel at how this genus has survived virtually unchanged in appearance for hundreds of millions of years. In light of the recent completion of the Selaginella moellendorffii genome sequence, this review is intended to survey what is known about Selaginella, with a special emphasis on recent inquiries into its unique biology and importance in understanding the early evolution of vascular plants.