Ontogeny of generative organs in Chimonanthus praecox L.

Comparative floral ontogeny provides new characters for systematics studies. Winter sweet (Chimonanthus praecox L.) is an aromatic, medicinal and ornamental plant. In the present study, the flowers were collected during different development stages and then, subjected to investigations through conventional histological methods. Samples were stained with Hematoxylin and Eosin. Results of microscopic studies have shown that anthers are tetrasporangiate. The anther wall composes 5-6 layers. The tapetum layer cells were multinuclear, indicating their high level of metabolic activity. Tapetum, tetrads and microsporogenesis are respectively secretory, tetrahedral and simultaneous types in Wintersweet. Anther dehiscence was completed through longitudinal splits. Through the inspection of pollen grains via SEM, it was revealed that the average length of polar axis of the pollen grains was 38.4 µm while the exine sculpture of pollen grains was identified as reticuloporait type. Through the investigation of the gynoecium it was revealed that winter sweet has 9-12 carpels that contain anatropous bitegmic ovules in which the tetrads are arranged in a linear form. The development of the embryo sac was of polygonum type.Studying flower characteristics such as organ formation can be useful in recognition of co-family species in this plant.