Morphological Studies of the Nymphaeaceae II. The Flower of Nymphaea

Abstract

1. The vascular anatomy and organogeny of eleven species and two hybrids of N ymphaea have been examined and described. 2. The arrangement of the floral organs is in a transitional stage between the ancient spiral phyllotaxy and a whorled condition, although superficially the carpels and, in some species, the appendicular organs appear to be in whorls. 3. Ovules are laminar and are attached between the dorsal and ventral carpellary veins. They have not been observed attached to the ventral limits of the locules. Rarely, they are attached to the median dorsal regions. 4. The peduncle typically has a large central vascular strand, a peripheral circle of large vascular strands which alternate with smaller ones, and an intermediate ring found in the septa between the principal air canals. Variations of this pattern are described. The central and the larger peripheral vascular strands are generally composed of two radially adjacent, collateral bundles. The inner bundle of each large peripheral strand is invert...