Growing our knowledge of grasses

Maria Vorontsova, Research Leader in Comparative Plant & Fungal Biology discusses the importance of grasses and reflects on Growing the Grass Classification: an international scientific meeting which took place in July.

Grasses feed the world

Many people do not realise that ‘grasses’ are not just the ubiquitous little plants we find in our gardens and on our lawns. Grasses are actually one of the most diverse and useful of all plant groups, with almost 12,000 species known across the world. The grass family (known as Poaceae) feeds the world: with wheat, rice, maize, sorghum and sugar cane all belonging to Poaceae. The grass family also covers over 25% of the world’s land surface with natural grasslands and savannas.

130 years of grass classification at Kew

Scientists at Kew have specialised in the study of grasses for 130 years, handling specimens from across the world. Using their knowledge of the small and complex reproductive parts, Kew scientists have constructed a grass classification system which is relied upon throughout the world. Kew grass specimens have been consistently identified to a high standard, and Kew’s herbarium collection serves as a reference library of grass diversity. 

Kew’s grass celebrity Derek Clayton turns 90

The most famous modern grass taxonomist at Kew is Derek Clayton. He assembled data on all grasses of the world and published the reference book Genera Graminum in 1986. This compendium of information allowed the study of grass diversity to take a leap forwards, and paved the way for later computerised systems. Despite the success of the book, Derek realised that a database would be more suitable, providing a more flexible means of storing and presenting information in the longer term. He built the first comprehensive taxonomic database, called GrassBase, which is now an active repository for species descriptions and associated data (Vorontsova et al 2015; Clayton 2016). 

On 18–19 July 2016 members of the worldwide community of scientists studying grasses gathered at The Linnean Society of London to congratulate Derek on his 90th birthday, thank him for his amazing work, discuss future research directions, and the continued development of GrassBase. Eighty delegates attended and listened to 29 presentations by scientists from Australia, China, France, Madagascar, Russia, South Africa, Switzerland, UK, and the USA (Linnean Society of London, 2016).

Meeting day 1: growing the grass classification

Following a welcome from Kew’s Director, Richard Deverell, the morning session traced the history of plant classification at Kew as the centre of the plant specimen exchange network of the British Empire. Gren Lucas and Steve Renvoize set the scene describing the generations of scientists who built the grass species knowledge base. Tom Cope spoke about the principles of classification, Derek Clayton presented his work on GrassBase, and Terry Macfarlane described other taxonomic databases using similar software. Rob Soreng compared the two latest Poaceae classification systems in current use: Kellogg (2015) and Soreng et al. (2015).

In the afternoon session Jerrold Davis reviewed the current state of knowledge on the origin of the grass family. Specialists then presented their latest research findings on different parts of the family.

Meeting day 2: biogeography, ecology and early career scientists

On the second day the discussion stepped beyond the grasses themselves and into broader interdisciplinary science. Caroline Lehmann and Colin Osborne put plants into the context of the global ecological importance of grasslands, savannas, the impact of fire, and vegetation change. Paula Rudall and Lynn Clark described their research on grass anatomy and its significance providing a deeper understanding of grass evolution and function. Pascal-Antoine Christin and Guillaume Besnard demonstrated the use of novel large-scale DNA sequencing to study extinct species and uncover surprises in the evolutionary history of photosynthesis. The new generation of grass specialists, graduate students and postdoctoral researchers also presented their work. The meeting concluded with a talk by Abigail Barker on Kew’s Plants of the World Online Portal, followed by a general discussion of ways forward in grass systematics and nomenclature.

Growing forward

Scientific research moves ahead through a myriad of independent research projects, advised by the globally interconnected community of scientists. This meeting provided a platform to showcase all of the multifaceted work being carried out on so many different aspects of the grass family. All our research programmes have been given a boost of inspiration by everything we learned. We will continue to collaborate and build on Derek’s work to understand grasses better, to help produce better crops and to build our understanding on managing the world’s ecosystems.

Acknowledgements

Meeting Organising Committee:

Maria S. Vorontsova (RBG Kew, UK)

Sylvia Phillips (RBG Kew, UK)

David Simpson (RBG Kew, UK)

Elizabeth Kellogg (Donald Danforth Plant Science Center, USA)

Rob Soreng (Smithsonian Institution, USA)

References

Clayton, W. D., Vorontsova, M. S., Harman, K. T. & Williamson, H. (2016). GrassBase - The Online World Grass Flora. Available online 

Kellogg, E. A. (2015). Poaceae. XIII: i–xv, 1–416. In K. Kubitzki (ed.) The Families and Genera of Vascular Plants. Springer Verlag, Berlin.

Soreng, R. J., Peterson, P. M., Romaschenko, K., Davidse, G., Zuloaga, F. O., Judziewicz, E. J., Filgueiras, T. S., Davis, J. I. & Morrone, O. (2015). A worldwide phylogenetic classification of the Poaceae (Gramineae). Journal of Systematics and Evolution 53(2), pp.117–137. Available online

Vorontsova M. S., Clayton,W. D. & Simon, B. K. (2015). Grassroots e-floras in the Poaceae: growing GrassBase and GrassWorld. PhytoKeys 48: 73–84. doi:10.3897/phytokeys.48.7159. Available online