"Hundreds of medicinal plants are at risk of
extinction, threatening the discovery of future cures for disease,
according to experts."
source: http://news.bbc.co.uk/2/hi/health/7196702.stm
I wonder if we could co plant some of these plants as an added reason to buy green. Even if there is no benefit towards production you may be keeping a species going until someone finds a use for it and you may be one of the few places a feedstock can be started.
Socialy and politically it would give people and governments another reason to support biofuels.