FLORAL ONTOGENY IN CYCLAMEN PERSICUM ‘F‐1 ROSEMUNDE ROSE’ (PRIMULACEAE)

Abstract

Floral ontogeny was examined in Cyclamen persicum ‘F‐1 Rosemunde Rose’ using a combination of light and scanning electron microscopy. The leaf plastochron index (LPI), earlier calculated for leaf elongation, was used to determine the length of each stage of floral development. LPI will provide a useful tool for selecting flowers of a given stage from large plant populations or from plants where flowers are small or inaccessible during early ontogenetic stages. Most features of floral development are similar to those previously described for other primulaceous genera. The petal‐stamen relationship, however, is unusual; stamens arise through periclinal cell divisions in the adaxial surface layers of common petal‐stamen primordia. Anatomical evidence suggests that the placenta is formed both by appendicular initials which give rise to the ovules and ventral carpellary bundles, and receptacular cells which form some, if not all, of the central axis.