Zahra Tavakkoli - Dept. of Plant Biology, Faculty of Biological Sciences, Kharazmi Univ. Tehran - Iran
Mostafa Assadi - Research Institute of Forests and Rangelands,Tehran, Iran.

The leaf epidermal structure of seven taxa from the genus Papaver  L. sect. Oxytona are investigated. All taxa have the type of anomocytic stomata on abaxial surface and no stomata is present on the adaxial surface. Within the section, the species and interspecific hybrids could be identified by the following characters: stomata size, the shape of the epidermal cells and anticlinal walls on leaf abaxial surface. Seed characteristics of the species of this section were studied using scanning electron microscopy and stereomicroscope. Seeds are reniform or sometimes falcate; the epidermal cells shape varies from polygonal and rectangular to irregular polygonal and rectangular; anticlinal walls are nearly straight in P. bracteatum and slightly sinuate in P. orientale and P. setiferum. The sculpturing pattern of testa is granulate-perforate in all taxa. Pollen grains size of seven taxa  and the exine structure of P. bracteatum and P. lasiothrix were studied by SEM. P. bracteatum has the smallest pollen grains and P. setiferum × P. bracteatum the largest pollen. The basic shape of the pollen grains is prolate-spheroidal. The aperture is tri-to tetracolpate. Moreover, taxonomically important characters of taxa were observed and measured. A positive correlation is found between stomata and pollen grains size and chromosome number. Our results revealed that seed morphological characteristics have not taxonomic value in separation of taxa from each other. Also, P. lasiothrix could be reduced as synonymy of P. bracteatum. Interspecific hybrid of P. setiferum × P. bracteatum is recorded here for the first time from NW Iran. For these taxa, taxonomical characteristics, localities and geographical distributions are presented.

Papaver, leaf epidermis, seed, Pollen grains, Morphology, Iran