You say tomato: Professor Sandy Knapp FSB

Botanist Dr Sandy Knapp tells Tom Ireland how her fascination with plants took her across the globe and into the Natural History Museum, London

The Biologist Vol 62(3) p24-27

Sandy Knapp has travelled to countless countries in her search for new species in the genus Solanum, a hugely diverse group of flowering plants that includes tomato, potato, aubergine and pepper plants. She grew up in New Mexico, where a love of the outdoors eventually led to an interest in natural history. Knapp now manages the Natural History Museum's vast plant collections as well as the Flora Mesoamericana, an inventory of the 18,000 plant species found in southern Mexico and the isthmus of Central America.

What led to you becoming a specialist in Solanum?

I went to a liberal arts college in California, where you don't decide what subject you want to focus on until later. I wanted to do marine biology but the class was full, so I took a field botany class instead. We went out into the desert with microscopes, and it was amazing. So I just decided "this is really fun, I am going to do this".

Initially I was interested in desert habitats and did a lot of exploration and hiking in the American south west. Then I went to Cornell and studied with Michael Whalen, who said I should work on Solanum, the plant he worked on. I didn't really want to work on something he had already worked on, but he suggested I go on a course in Costa Rica for six weeks. I fell in love with the tropics and it was clear that these plants were fascinating and really complicated, and there were lots of them still to be discovered and described.

It has kept me busy ever since. It's one of about 10 genera of flowering plants that have more than 1,000 species, which is unusual. Why are there so many? I see my work as an exploration of the diversity of this megadiverse genus. One reason they are put in the same genus is that their flowers all look the same. However, the rest of their bodies are really very different – I am interested in that.

When looking for new species, how do you decide where to look?

There are two types of collecting. When you're looking for something in particular, you go to places people have found it before or places like them. Another kind is going where people haven't been collecting before, and then you just collect everything that has flowers or fruits. Not necessarily biodiversity hotspots, either: just because something has a lot of species doesn't mean it is more interesting. Sometimes places are thought of as biodiversity hotspots because we've recorded everything that's there, so going to places that are less well known is important. There are very few regions people haven't been, but there are gaps. There are places that are not species rich, but knowing more about them is still important.

Wherever you collect, it is important to have permission to do so. Biodiversity is part of the national heritage of a country, as well as being of global importance, so getting the correct permits from local authorities is crucial. What's great is that you form working relationships with the scientists in those countries. However, it's no longer just hopping on a ship, collecting stuff and popping back.

Where has been your favourite place to collect species?

It's really hard to say. I've liked everywhere: I love the deserts, the tropics, the Andes. I had a job once where I was the Missouri Botanical Gardens' 'Man in Panama' – they gave me a trailer to live in and a truck to drive, and I had to collect a certain number of plants a month. It was fantastic. I tried to go to the Darién because nobody had collected there very intensively.

How does working in a draughty British museum compare to that?
What's fantastic here are the collections. They are like an incredible physical database of things that occurred somewhere at some time. I find more species in the collections here than in the field – specimens that were collected a long time ago and have never been described.

Do you have a favourite species or specimen?

I wrote a book called Flora, and the reason I wrote it was I was inspired by a painting by George Ehret from the museum that the librarians showed me, which is now on display at the museum. It's on vellum and shows Magnolia grandiflora – the southern magnolia – with its evergreen leaves and big, creamy flowers, and if the museum were burning down, that's what I would save. I absolutely love it.

Do you think the museum displays enough plants?

There are some plants represented in our Treasures gallery and there are a lot of plants around in our new exhibitions. However, if you look up instead of sideways at the Diplodocus, the ceiling is covered in beautiful plant paintings. In fact, it is so magnificent that a colleague and I wrote a book on the botany of the ceiling.
The world is essentially divided into two types of person: people who look up at the ceiling and those who don't. Having something hanging from the ceiling means plants will really become more of a focus, which is great.

Did you ever imagine that changing the Diplodocus display in the Hintze Hall would cause such a furore?

I think we did because it's something that people care about. It's great for us because it shows people care about us. I think it's going to be exciting to have something new, and the Diplodocus hasn't been there forever anyway – there was a sperm whale and some elephants before that. When we were discussing the new display, I joked that we could suspend a huge potato from the ceiling.

In our latest issue, Dawn Sanders argues that we suffer from 'plant blindness', a sort of inability to see the importance of plants. Do you think they are overlooked by society compared to animals?

People care, but they don't know they do. I think people recognise that plants provide the oxygen that we breathe, which is pretty important. I sometimes give talks to schoolchildren and once asked: "Who has eaten a plant today?" None of them put up their hand. I said: "Who's eaten toast, or cereal, then?" Many of them had, but we just have so much less contact with nature due to our urbanised lifestyles.

Plants are interesting because they do behave, even though they appear to just sit there. It's just on a very different time scale, and we as a species struggle to perceive what's going on unless we can see it on sped-up footage or in some other way. Signalling between plants is fascinating – for example: if your neighbour is being eaten by a caterpillar, it produces signals that tell you to increase your alkaloid content – that's extraordinary. They do behave, it's just we don't see it – it's not like antelopes posturing.

Do you worry taxonomy is in decline?

I worry about the biology of looking at whole organisms in the field. But I think it's making a comeback, actually, with our emphasis on food security and caring for a planet. It's like a pendulum. There are fads in science, just like fashion goes back and forth between tight jeans and loose jeans. The pendulum is swinging back and we really do need to understand the organism if we are going to think about things in a more comprehensive way.

How do you explain why your work is important?

If you think about how things evolve and change, there are changes in the DNA sequence and at the molecular level but those changes are driven by the interaction and selection of the whole organisms themselves. Understanding those things – the whole organisms, how they're put together and how they interact with the environment – is really important as an additional set of information about life. Across biology, things are becoming more 'molecular'. Molecular isn't more modern, it's just a different data set. It's not intrinsically better. Unlike physics, which often throws obsolete techniques away, we still use our old techniques. We keep adding different views on different scales, which is great.

Some scientists think the requirement to prove the impact of their work is narrowing the ambition of science. What do you think?

It could if impact were defined in a narrow commercial sort of way, but it isn't. Actually, that's one of the good things about the impact agenda. Scientists tend to think it means a commercial impact, but it can also be a societal impact – for example, coming to a museum can change people's lives. That is real impact, but demonstrating it is tricky – not as easy as showing commercial success, but arguably much more important. It's good for scientists to think how their work might change somebody's life.

Dr Sandy Knapp FSB is head of the plants division of the Natural History Museum, London. She specialises in the megadiverse genus Solanum