Next time you are out and about, take a look around you. Wherever you are, there will be plants. And probably quite a few plant species. The flora of Scotland contains some 1,000 species of flowering plants with many more introduced from abroad. Which, although it might sound a lot, is a tiny percentage of what we already know to be out there. And those we are yet to discover.
While all individual Scottish plant species are important, our flora is tiny on the global scale. Scotland’s flora includes only 1 in 20 of all European plant species. Compare this with Brazil, for example, which alone harbours more than 35,000 species of flowering plant. Yet, impressive as this is, even the flora of Brazil pales in comparison to the largest flora in the world. So, where is that? As a botanist it shames me to admit that we do not know. The largest flora in the world consists of the undiscovered and undescribed species scattered across the continents. Every single Scottish plant species is matched by 70 species growing, unnoticed, unnamed and undiscovered.
At the Royal Botanic Garden Edinburgh (RBGE), we are doing our utmost to find these species. I am a taxonomist, which means I categorise plants. When a plant does not fit into an existing species, my role is to “describe” a new one. In this quest, I travel to the field – in my case South America.RBGE has one of the largest concentrations of plant taxonomists in the world. Collectively, our taxonomists describe an average of one new plant species per week. Recent discoveries range from a 45m tall, 105 tonne rainforest tree in the pea and bean family to the world’s smallest Begonia, reaching fewer than 3cm tall, weighing less than a penny, and described on Friday, 17 February. While vastly different in scale, these two new species and many more have something in common. They are critically endangered in the wild. For many, including the giant bean relative, the threats are the usual suspects: destruction of habitats by loggers, industry and agriculture. The Begonia is threatened by something more unusual. Only around 5,000 live on a single Peruvian cave mouth roughly the size of a two-up two-down. A proposed “ecotourism” trail will disturb this pristine habitat, perhaps so much so that the species will not survive.
We simply do not know what useful properties undescribed plants will have, but without knowing species exist how can the scientific community study them? Can we afford to miss out on the next cure for cancer or super-crop?
Finding and describing 70,000 unknown species is a daunting task, but taxonomy is not the slow and crusty old science it may seem. Our ability to share herbarium data and images around the world instantly has had a huge impact upon the speed of taxonomic work, while DNA techniques allow us to find and describe species hiding in plain sight.
There is hope too for the world’s smallest Begonia. Following its description RBGE scientists and the Peruvian authorities are working together to promote a more sustainable tourism. at its only known locality.
Peter Moonlight is a Research Scientist at the Royal Botanic Garden Edinburgh, specialising on understanding the links between species richness and ecology in Begonia