This is why we can't have nice species: Last week one of the world's rarest plants was stolen from public display in London at the Royal Botanic Gardens, Kew. An unknown thief or thieves walked in, pulled or dug up the plant and disappeared with it.

The tiny thermal water lily (Nymphaea thermarum) is the smallest water lily in the world, with a flower barely the size of a human fingernail. Native to a single hot spring in Rwanda, the plant went extinct in the wild a few years ago after the spring was drained for local agricultural use. As I wrote back in 2010, the water lily was saved from extinction by botanist Eberhard Fischer, who discovered the species back in 1985 but never figured out how to propagate it in captivity. That changed in 2009 when Kew horticulturist Carlos Magdalena figured out that the lily thrived not in water, like all other water lilies, but in damp mud at very specific temperatures and atmospheric conditions.

Since then Kew has managed to grow about 50 of the plants, and has transferred a handful to other facilities. Nevertheless it remains critically endangered. Kew considers the stolen lily to be "priceless" and vital to the conservation of the species. Police are currently investigating the crime of the lifted lily.

Guy Barter, chief adviser to the Royal Horticultural Society (which runs Kew Gardens), told the Telegraph that theft from a public garden is unfortunately common as well as dangerous to the plants. In this case he blamed something more sinister than the general public: "plants stolen to order and sold for profit" for collectors who will "sink to any depth to have something they really want."

Look, I get the collector's mentality. I'm the kind of guy who has spent hundreds of hours in dingy used bookstores or comic book shops to track down that one last early Joe R. Lansdale paperback or obscure Matt Howarth comic that I must have for my collection. But stealing rare plants and animals from captivity and the wild or checking off the list of species that you have hunted and killed, that's a drive I don't understand. This is why smuggled, endangered tortoises sell for tens of thousands of dollars, why rare orchids are black-market treasures and why a permit to hunt an endangered black rhino can sell for $350,000. And for what? For a head to hang on your wall, a tortoise to wander the grounds of your estate or a plant you'll have to struggle to keep alive under incredibly precise conditions?

It might not be easy to find whomever stole this water lily. Kew, unfortunately, didn't have a security camera pointed at right spot. The tiny plant was no doubt easy to hide as the thief slipped out of the garden. Even with police investigating, it may be gone forever. Unfortunately, with precious few plants and seeds available to keep the population of this species growing, the footprint of this one plant's loss may be felt for a long time to come.

Photo: Nymphaea thermarum, courtesy of Kew Gardens