Vishnevetsky, J., Department of Agricultural Botany, Faculty of Agriculture, Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100, Israel
Lilien-Kipnis, H., Dept. of Ornamental Horticulture, Agricultural Research Organization, Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
Azizbekova, N., Department of Agricultural Botany, Faculty of Agriculture, Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100, Israel
Ziv, M., Department of Agricultural Botany, Faculty of Agriculture, Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100, Israel

Nerine is an autumn flowering perennial bulbous plant native to southern Africa belonging to the family Amaryllidaceae. Irregular flowering is often encountered in commercial flower production. The annual life cycle of Nerine sarniensis is characterized by flowering in autumn prior to leaf emergence, active leaf growth during winter and early spring, followed by leaf senescence and a rest period during the hot dry summer. The objective of this study was to follow the ontogeny of N. sarniensis cv. 'Autumn Glory' with special emphasis on differentiation and development of vegetative and generative apices under outdoor growing conditions in Israel. It was found that leaf development lasted approximately eleven months, with active leaf growth of up to five months, depending on the onset of high temperatures in late spring. For most of the year the bulb contains two inflorescences at different stages of development. Inflorescence development from initiation to anthesis lasted 21-22 months, i.e., active development occurred in the bulb during its rest period. Development was only arrested for approximately two months at the end of summer, just prior to flowering.