Abstract:

Leaf anatomy of six genera was investigated. The petiole of Brasenia

schreberi possesses a pair of bundles, the other five possess closed, scattered

vascular bundles, resembling those of the Monocotyledons. True vessels are ab-

sent. Air passages are present in the ground tissue of the petiole except for Nuphar

pumilum. Leaves are all dorsiventral. Stomatal apparatuses of the Ranunculaceous

type are generally confined to the upper surface of the  lamina,  but  fewer

stomata are found on the lower surface of the lamina of Nelumbo nucifera. The

stomatal apparatuses of Nelumbo nucifera are of the Haplocheilic type in develop-

ment,  but  of  the Ranunculaceous  type  at  maturity.  Hydathodes  and

sclerenchymatous idioblasts are present only in Nelumbo nucifera. Glandular hairs

and hydropotens occur on the lower surface of the lamina in all the investigated

species except Nelumbo nucifera. Astrosclereids are present in all the taxa except

Brasenia schreberi and Nelumbo nucifera. According to observations we consider

that the genus Brasenia is a primitive one in Nymphaeaceae and it has a close

phylogenetic relationship with Cabomba. They may be treated as an independent

family,  Cabombaceae,  which is better included  in  the  order Nymphaeales.

Nymphaea, Nuphar, Euryale and Victoria are closely related to one another and

should be retained in the family Nymphaeaceae. Nelumbo shows, specialized fea-

tures distinct from those of the rest of the Nymphaeaceae. It should be segregated

not only as a distinct family but also as a distinct order, Nelumboales.

Key words: Nymphaeaceae, Leaf, Comparative anatomy