Ancient flower lives only on two Spanish cliffs, and uses ants to survive

I love stories like this. The reality that there are tiny, tiny corners of the world that contain plants or animals that exist nowhere else.

This story begins with a cliff-hanger. On the Spanish side of the Pyrenees mountains, around 850 metres above sea level, two adjacent cliff faces hold the entire population of Borderea chouardii – one of the world’s rarest plants. It’s a small herb that grows into crevices in the rock. Its leaves are heart-shaped and its flowers green and unassuming. There are around 10,000 individuals here, all growing on a square kilometre of vertical rock.

In 1973, I visited London for the first and, to this point, only time**. During that visit, I took a bus tour of Hampton Court and Windsor Castle.

Our very voluble guide took care to point out unique items, such as the notch in an outer wall–I have forgotten whether it at Hampton or Windsor–that marked the height of Cromwell’s tallest soldier. But there was something else he said that I remember, and I swear I am not misremembering even though I was 15yo at the time and not as engaged in soaking it all in and looking at all the old stuff as I would be, say, today. He said that there was a tree in the garden–again, I don’t recall at which site–that did not grow anywhere else in the world. I recall the phrase “Eden tree,” but *that* could be misremembrance. I have searched online every so often for information about the gardens, but have yet to find any reference to a unique tree.

**not counting a couple of quick jaunts through Heathrow on the way to and from connecting flights to Glasgow/Intersection ’95.