Indonesian 'coffee plant' named after Leiden researcher
Research on Asian plants is his life's work. Now a crown is added to that: a plant from the coffee family bearing his name. Paul Kessler is LUF professor of botanical gardens and botany of South East Asia and Scientific Director of the Hortus botanicus. 'Completely unexpectedly, you get to see the results of your work 30 years later. I find that really special.’
As a child, Paul Kessler actually wanted to become a zoo director, because he loved animals. But that changed. From the age of 12, he went to stay with his parents’ friends in De Bilt every summer. ‘They had a perennial plant nursery and that’s where my love for plants was born.’ Kessler discovered that he loved weeding, and in the process he became fascinated by the plant world. ‘I learned about the distribution of plants and what care they needed. I knew the Latin names and learned to collect seeds.’
‘When it comes to South East Asia you have to be in Leiden anyway’
Kessler went on to study Biology in Kaiserslautern in Germany. He did his master’s and PhD in plant systematics with a professor who researched a tree family (Annonaceae) in Sri Lanka. That really fascinated him. And that choice also meant he ended up in Leiden. ‘They didn’t have a herbarium in Kaiserslautern and when it comes to Southeast Asia, you have to be in Leiden anyway. Leiden has had a long-standing connection with Indonesia, and has built up impressive plant collections over the past few centuries. And of course I already spoke Dutch; it was a subject at school and I practised it every summer.’
Fifteen years of research in Indonesia
After completing his PhD in Germany, Kessler eventually went to work as a researcher in Indonesia for the National Herbarium of Leiden University. For six to nine months a year, he conducted research in Borneo. As a biologist, he inventoried the lowland forests. For fifteen years. His family was in the Netherlands. And yes, that was quite difficult. ‘I didn’t often take my children to school,’ Kessler says. ‘But anyway, there was not much choice, we had to deal with the situation.’
During that period, in 1992 to be precise, he also collected the plant now named after him. It was a plant from the coffee family Rubiaceae, of the genus Timonius. ‘At least that’s what we thought at the time. Recently, two fellow researchers took another look at the entire genus. And they found out that the plant I had collected was an unknown species. New to science. And so it had to have a name.
He heard about it through the mail. In his colleagues’ publication, Kessler read to his surprise that the plant was now called Timonius kessleri. ‘It was really a big surprise. You have been doing years of fieldwork, mapping plants and trees for science. And then 30 years later it turns out that you had discovered a new species. The fact that it now bears my name is incredibly honourable.’
Text and photo: Christi Waanders