Abstract
The nine extant genera within the Nymphaeaceae s l (Water Lilies) are shown to be separable from one another on the basis of seed morphology In particular, epidermal detail, vertical section of the testa and relative position of the micropyle and hilum are diagnostic for each genus These features are considered in connection with current systematic treatments of this family Fossil seeds are reviewed at the generic level and many of the seeds previously assigned to Brasenia ovula (Brong ) Reid and Chandler are shown to belong to an extinct genus of Nymphaeaceae intermediate between the currently accepted families Cabombacaceae and Nymphaeaceae s s They are redescribed as Sabrenia chandlerae gen et sp nov. The British Tertiary fossils Brasenia spinosa Chandler, Palaeonymphaea eocenica Chandler emend and ?Nymphaea liminis sp nov are described Fossil material of Carpolithes ovulum Brongniart 1822a, Brasenia victoria (Casp ) Weberbauer 1893, B teumeri Kirchheimer 1935, B tenuicostata Nikitin 1965 and Nymphaea arethusae Grambast 1962 has been studied for comparative purposes The use of ‘?’ before the extant generic name is advocated when all features of a fossil indicate that it may be placed in a living genus but when certain additional, critical features of the living genus are lacking on the fossil.