Map outlines most endangered plants of the U.S.

A recent study estimates that the number of plants that have disappeared since 1750 is double that of all birds, mammals, and amphibians combined.

Sadly, not many people seem to be aware of that.

To raise awareness, a team of researchers and artists collaborated to celebrate the fragile existence of plants that are teetering on the brink of extinction.

The result is a series of botanical art posters that hide a disturbing secret -- they illustrate the most vulnerable plant in all 50 states.

See the full list here.