Micromorphologic study of flowers and seeds in Amaranthus subgen. Amaranthus sect. Amaranthus from Iran

The genus Amaranthus, with about ۷۵ to ۹۵ species, is more distributed in temperate and tropical regions of the world. Species of this genus are considered from various aspects of agriculture as food, medicinal plants and important weeds. The genus Amaranthus, with ۱۴ species in two subgenuses is distributed in Iran. From Iran, in each subgenus, there are members of two sections. Six species (A. caudatus, A. cruentus, A. hybridus, A. hypochondriacus, A. powellii and A. retroflexus) from sect. Amaranthus have been reported from Iran so far. Due to morphological diversity and hybridization between these species, accurate identification of these taxa is difficult and requires study and attention to different morphological characteristics. Therefore, in this study, an attempt has been made to facilitate the separation of these taxa from each other by accurately describing the reproductive traits related to inflorescences, flowers and seeds. The predominant form of the inflorescence in the sect. Amaranthus species is the terminal inflorescence, but axial form are also scattered throughout all of these plants. The distinct difference between A. hybridus and A. powellii is in the length of their leaves. In addition, the smaller seeds in A. powellii, despite the similarity of the two species, help to distinguish them. Also, the length ratio of A. hypochondriacus bracts to its tepals is more than A. caudatus and A. cruentus and its seeds are clearly larger. A. retroflexus is distinguished from the rest of the species in this section by its long, acute bracts and often having tepals with emarginate or retuse tips.

کلیدواژه ها:

Amaranthaceae ، Flora of Iran ، Morphology ، Weed