[xerula]

These types of complex mutualistic interaction between multiple species are precisely what biologists predict are most prone to being disrupted by environmental degradation and climate change, leading to high extinction risk for the dependent species. This fascinating flower (one of the few "living fossils" in the yam family) has been successful in persisting over vast evolutionary time scales, yet is now critically endangered. In the face of the mass extinction event we humans seem determined to inflict on our biosphere, conservationists often advocate concentrating our efforts on saving ancient species like Borderea chouardii, because they present relatively isolated, long branches on the tree of life. This means that saving them equates to saving the maximum evolutionary history - and thus the maximum phylogenetic diversity - with the minimum effort. (In practice, many other factors have to be taken into account.)