Dr Mark Spencer reckons that plants are woven into the fibre of his being. “I’ve been obsessed with them since I was a toddler growing up in rural Warwickshire,” he says. “I dream about them and I navigate my way around towns and cities by remembering something that’s growing on a street corner.” Certainly, his every waking hour is spent working with plant material, whether he is advising on invasive species, teaching a class on plant identification, looking after the unique herbarium samples at London’s renowned natural history institute, the Linnean Society, or studying flora to help piece together what has happened at a crime scene.
A single leaf stuck to a shoe or pollen attached to clothing can pin a suspect to a crime scene
This latter endeavour – forensic botany – has become one of Mark’s specialities over the past 15 years, ever since he received a chance call from a detective when he was working as botany curator at the Natural History Museum in London. “I’d never been involved in forensics before, but a man’s body had been found in a ditch and the police asked me whether I could tell them how long it had lain there.” Plants, it seems, can provide vital evidence in serious crime scenes. The growth patterns of brambles, for example, are surprisingly ordered and can help establish a timeline. “By studying the number of stems and their rates of degradation, you can unpick the chronology. Establishing that a body has been there for, say, eight or nine years is so useful to the police in narrowing down records of missing people.”
I feel I am doing something really valuable that can help give hope and some closure after tragedy
Trace evidence can help unlock a mystery too, when fragments of plant material – a single leaf stuck to a shoe or a car tyre, for example, or pollen attached to clothing – can help pin a suspect to a crime scene. It is painstaking, meticulous work and Mark’s accrued knowledge of British plant life and years of rigorous scientific study make him ideally suited to it. Even so, it has taught him to look at plants in a different way. “You need to take in the whole scene, not derive a hypothesis from the first thing you see. The accuracy of my report is vital and I feel I am doing something really valuable that can help give hope and some closure after tragedy.” Now aged 55, he feels it is one of the things he is most proud of in his life.
Early on, it was always assumed that Mark would go into gardening, but two years into the Kew Diploma in Horticulture he had “the creeping realisation that this was the wrong path” and left. After a few years of dithering, the pull of plants came back, and, at 27, he signed up for a botany degree at Reading University, closely followed by a doctorate in mycology. “That was the most fun – being in my little scientific bubble staring down a microscope looking at fungi grow.” The Linnean Society of London, where he has been honorary curator for the past decade, played a vital role in his achieving his doctorate. “As a working-class lad, I couldn’t have afforded to do a PhD, but the Society, together with my supervisor, helped find the funding from a private donor.”
We are at risk of losing two-thirds of our native flora here and that is tragic
Caring for the Society’s precious resources has helped Mark develop a strong affinity for historic botany. “The vault contains the personal collections of Carl Linnaeus, the father of modern taxonomy. These are globally important foundational materials for understanding plant diversity.” At the Natural History Museum, where he worked for 12 years, until 2016, first as a research assistant on Carl Linnaeus and then as the curator of the British and Irish Herbarium, he and fellow scientists used the collections to research the impacts of climate change on biodiversity, another subject he is passionate about.
One area of plant science that he sees as a ray of hope is mycology
Mark is also the London Natural History Society’s vascular plant recorder, which gives him an overview of Greater London’s flora. “A massive survey, spanning more than 20 years and involving dozens of volunteers, is underway and we know that London’s biodiversity is in serious decline. We are at risk of losing two-thirds of our native flora here and that is tragic.” Causes include habitat degradation, poor conservation management and the expansion of invasive species such as buddleja, which, says Mark, are causing widespread ecological damage by out-competing other native plants. “A depleted natural world is a less beautiful and rich world for all of us. Cities are important early warning systems for what is happening on a wider scale. Globally, loss of biodiversity is a risk to agricultural systems as well as to human wellbeing.”
These losses, together with the threats from climate change, give Mark serious cause for concern, but one area of plant science that he sees as a ray of hope is mycology. “There were no jobs in mycology when I completed my PhD, but now this is one of the great areas of exploration for our biodiversity. Fungi, along with bacteria, are biochemical wonderlands,” he explains. “They are the future, offering so many possibilities in new materials, new science and our understanding of the natural world.”
Useful information Find out more at markspencerbotanist.com. For details of guided tours and upcoming events at the Linnean Society of London, see linnean.org