Biosystematic studies for some Egyptian Amaranthus L. taxa and their significance in their identification.

Abstract

Ten Egyptian Amaranthus species have been collected from the field and their inflorescence, floral characters, pollen grains, fruits, and seeds have been studied carefully by using both stereo-and Scanning electron microscopes. The results has been analyzed using PAST program and gave clustering dendrogram for the studied taxa. The result obtained showed that from the most important character in the identification of the taxa is the number of flowers/unit area of the terminal panicle, beside the type of inflorescence. Pollen morphology gave little account in the circumscription of the studied taxa. Type of fruits dehiscent versus indehiscent fruits can be used in the recognition of some species. Seed shape, micropyle position and microstructure features are more efficient in the identification of the studied taxa beside the fruit characters. In spite of that, seed characters can help in distinguishing the species, but they are not in accordance with the division of the taxa into distinct sections.