| Abstract: | Leaf anatomy of six genera was investigated. The petiole of Braseniaschreberi possesses a pair of bundles, the other five possess closed, scatteredvascular bundles, resembling those of the Monocotyledons. True vessels are absent. Air passages are present in the ground tissue of the petiole except for Nupharpumilum. Leaves are all dorsiventral. Stomatal apparatuses of the Ranunculaceoustype are generally confined to the upper surface of the lamina, but fewerstomata are found on the lower surface of the lamina of Nelumbo nucifera. Thestomatal apparatuses of Nelumbo nucifera are of the Haplocheilic type in development, but of the Ranunculaceous type at maturity. Hydathodes andsclerenchymatous idioblasts are present only in Nelumbo nucifera. Glandular hairsand hydropotens occur on the lower surface of the lamina in all the investigatedspecies except Nelumbo nucifera. Astrosclereids are present in all the taxa exceptBrasenia schreberi and Nelumbo nucifera. According to observations we considerthat the genus Brasenia is a primitive one in Nymphaeaceae and it has a closephylogenetic relationship with Cabomba. They may be treated as an independentfamily, Cabombaceae, which is better included in the order Nymphaeales.Nymphaea, Nuphar, Euryale and Victoria are closely related to one another andshould be retained in the family Nymphaeaceae. Nelumbo shows, specialized features distinct from those of the rest of the Nymphaeaceae. It should be segregatednot only as a distinct family but also as a distinct order, Nelumboales. |
