PREFACE. 
The late Mr. C. B. Clarke, whose lamented death was recorded 
in the Kew Bulletin for 1906, p. 271, devoted much of his time 
during the last twenty years of his life to a critical study, in the 
Herbarium at Kew, of the natural family Cyperaceae. The work | 
he had set before him was the completion of a general monograph 
of the family. As this work progressed he became by degrees 
the recognised authority on the subject, to whom botanists of 
every nationality submitted for examination collections of 
Cyperaceae from all parts of the world. The results of his 
studies were incorporated in his monograph which was still 
unpublished when he died. The monograph was complete so 
far as references to material submitted to him for study are 
concerned, but was not arranged for publication. When the task 
of arranging the manuscript was taken in hand it was found that 
the monograph in its entirety must occupy 4,000 pages in octavo, 
and, apart from the cost of printing, for which there is at present 
no provision, the task of passing it through the press must 
occupy the time of a eompetent editor for several years. 
At the same time a few of the genera and a considerable 
number of the species described in the monograph have not been 
published. The specimens in the Herbarium at Kew which 
represent these unpublished species are authentically named by 
Mr. Clarke. The names attached being, however, nomina nuda, do 
not lend themselves for use in the routine work of botanical 
determination. As the issue of the whole of the manuscript is 
not immediately practicable it is a matter of urgent public interest 
that the unpublished species therein described be provided with 
references that admit of formal citation. The only satisfactory 
way in which the object in view can be effected involves the 
presentation of the author’s own diagnoses of all the new genera 
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