There has always been a fear of the annihilation of humankind. Plague, global war, global cooling, global warming, judgment day, etc. But, what if not everyone perishes? It seems that a lot of other people have considered this.
As we speak Norway has broken ground on the doomsday vault. If the seeds of all the world's plant life (some 3 million is what they expect) were able to be housed as a form of Noah's Ark, maybe survivors could revive them at a later date. Kind of reminds me of the Lost World idea and maybe a vault containing DNA from many animal species can also be held for future generations. Anyhow, my question to you is: If there was only one herb that you could keep from disappearing from existence, what would it be?