Historically, the collection is particularly strong in specimens from Africa, India and Brazil, but there is a wide range of material from all parts of the worldsedges are present. It is fair to say that nearly all the sedge species known to science are represented by specimens in the Herbarium. About two-thirds of the specimens sent to Kew require naming and it is from this material that new species may be discovered. Surveys of these using scanning electron microscopy are yielding many useful characters. New techniques and sources of data, including DNA sequencing, are continually being looked at in order to improve the classification of sedges.
Special emphasis is placed on cladistic and phenetic techniques to analyse data.
Their inflorescence structure is unique in Cyperaceae but difficult to interpret due to its reduced nature. A better understanding of the tribe may hold important clues on the evolution of Cyperaceae. The genus Mapania has been revised and work is proceeding on Hypolytrum . Attention is also being given to Scirpus s.l. These occur worldwide and have considerable economic importance, but are rather poorly known.