Evolution, diversity and conservation of Cyperaceae

Researching the evolution, diversity and conservation of Cyperaceae, one of the World’s most diverse monocot families.

Microdracoides squamosus

Cyperaceae (95 genera, 5,600 species) is the third largest monocot family. Sedges have been the subject of research at Kew for many years and a profound knowledge of this beautiful family has been built up during the past decades. Our research focuses on the biodiversity, evolution and conservation of Cyperaceae, using a multidisciplinary approach and focusing on a range of genera and geographical areas.

Current research by Isabel Larridon is aimed at investigate evolution, diversity and conservation of the genus Bulbostylis (hairsedges) using an integrative taxonomic approach incorporating (micro)morphological and targeted sequencing data obtained using the Angiosperm-353 baits developed for Kew’s Trees of Life Initiative. This involves the work of 3 PhD students: Jérémie Morel (NERC SSCP DTP student) working on mainland Africa, Fitiavana Rasaminirina (funded through the Today’s Flora for Tomorrow project) working on Madagascar, and Juliene Maciel (based at Museu Paraense Emílio Goeldi and Universidade Federal Rural da Amazônia) working on the Neotropics.

The largest Cyperaceae genus in the tropics Cyperus with more than 960 species. Species delimitation in Cyperus is often problematic. Currently, Martin Xanthos is trying to resolve the taxonomy of an African species complex characterised by white-glumed spikelets which includes amongst others Cyperus margaritaceus and Cyperus niveus. Luciana Pereira da Silva is working to complete her PhD at the Universidade Federal de Santa Catarina on the taxonomy, phylogeny and evolution of Cyperus in the Neotropics.

Recent research of Isabel Larridon was aimed building a framework to investigate evolution if Cyperaceae using targeted sequencing data obtained using the Angiosperm-353 baits This resulted several high impact papers and a Special Issue on Cyperaceae in Journal of Systematics and Evolution.

The genus Scleria (about 250 species), commonly known as nut rushes or razor grasses, has a pantropical distribution and can occasionally be found in (warm) temperate regions. This genus was the topic of a PhD project by Kenneth Bauters at Ghent University under the guidance of Isabel Larridon and David Simpson at Kew. His research resulted in a new infrageneric classification, new species to science, and a taxonomic revision of Scleria subgenus Hypoporum. The Scleria species from Madagascar were studied during a Master project by Javier Galán Díaz at Kew supervised by Isabel Larridon. Currently, Javier is applying the EDGE approach to investigate the conservation of the genus.

Previous research focused on Cyperaceae tribe Schoeneae. This research resulted in the publication of two new genera to science, one endemic to New Caledonia and the other endemic to the Seychelles, and aided in resolving the very confusing relationships in this group of Cyperaceae. This research also enabled redelimiting the genera Costularia and Tetraria. Research into Cyperaceae tribe Abildgaardieae among others resulted in the small African genus Nemum being lumped in the large pantropical genus Bulbostylis. This was followed by a phylogenomic study of the tribe stabilizing the generic level classification of the tribe.

Through fieldwork, data and plant specimens and samples are assembled which are incorporated into Kew’s collections and provide further baseline data and plant material needed for research and conservation purposes.

Objectives

  • Avoid the extinction of (near) endemic and threatened Cyperaceae species in Africa and Madagascar through inclusion in the IUCN Red List and in Important Plant Areas.
  • Contribute to Kew’s Science Strategy including the Tropical Important Plant Areas and Plant and Fungal Trees of Life projects.
  • Construct a new DNA-based classification for the Cyperaceae family at tribal and generic level.
  • Build a solid framework to investigate evolution in Cyperaceae.
  • Assess the species limits in the Cyperus margaritaceus-Cyperus niveus species complex.
  • Investigate generic limits and relationships in Cyperaceae tribes Abildgaardieae and Schoeneae.
  • Construct a molecular phylogeny of Scleria and trace evolution of taxonomically important characters to obtain insights into its biodiversity and evolution, and establish a new infrageneric classification for the whole genus.
  • New phylogenomics-based classification of the Cyperaceae
  • Revision of the African Cyperus species with white-glumed spikelets
  • Revision of Cyperus in Brazil
  • Revision of the African and Malagasy species of Costularia
  • Molecular phylogenetic study of Costularia s.l.
  • A new infrageneric classification of the genus Scleria.
  • Conservation assessments of the (near) endemic and threatened Cyperaceae from Africa and Madagascar.

International

  • Prof. Paul Goetghebeur, Ghent University, Belgium
  • Prof. Muthama Muasya, University of Cape Town, Republic of South Africa
  • Prof. Marcial Escudero, Universidad de Sevilla, Spain
  • Prof. Santiago Martin-Bravo and Dr Pedro Jimenez-Meijas, Universidad Pablo de Olavide, Spain
  • Prof. Eric H. Roalson, Washington State University, United States of America
  • Prof. Julian R. Starr, University of Ottawa, Canada

Larridon I, Zuntini A, Léveillé-Bourret É, Barrett RL, et al. (2021)

A new classification of Cyperaceae (Poales) supported by phylogenomic data.

Journal of Systematics and Evolution 59(4): 852-895.

 

Larridon I, Spalink D, Jiménez-Mejías P, Márquez-Corro JI, Martin-Bravo S, Muasya AM, Escudero M (2021)

The evolutionary history of sedges in Madagascar.

Journal of Biogeography 48: 917-932.

 

Larridon I, Villaverde T, Zuntini A, Pokorny L, et al. (2020)

Tackling rapid radiations with targeted sequencing.

Front Plant Sci 10: 1655.

 

Larridon, I., Rabarivola. L., Xanthos. M. & Muasya, A.M. (2019)

Revision of the Afro-Madagascan genus Costularia (Cyperaceae): infrageneric relationships and species delimitation

PeerJ 7:e6528.

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Related links

Trees of Life Initiative