University of Isfahan Taxonomy and Biosystematics 3115-9001 14 50 2022 05 22 A Study of Flora, Life Form, and Chorology of Plant Species in Gamasiab Region of Nahavand, Iran بررسی فلور، شکل زیستی و عناصر رویشی منطقۀ گاماسیاب در نهاوند ‏(استان همدان)‏ 25 64 26632 10.22108/tbj.2022.133362.1197 EN Keivan SafiKhani Assistant Professor, Research Division of Natural Resources Department, Hamadan Agricultural and Natural Resources Research and ‎Education Center, (AREEO), Hamadan, Iran Journal Article 2022 04 20 The present study aimed to provide a floristic list and determine the life forms and chorology of species in the Gamasiab region in Nahavand, Iran. The region includes part of the Zagros Mountain (i.e., Garin Mountain or Geru), which includes several peaks. The highest peak of these heights in Hamedan province is the Yalkabud, with an altitude of 3541 meters above sea level, and this width area is 1899 hectares. Plant specimens were collected and identified from different points of the Gamasiab region during the appropriate seasons between 1993-2021. The plant biological spectrum of this region was plotted by determining the percentage of species belonging to each biological form. The percentage of regional vegetative elements was determined based on the geographical distribution data of identified species and resources. The plants identified in this area involved 51 families, 203 genera, and 311 species. Totally, the region included 7 families of monocots, 43 families of dicots, and 1 family of pteridophytes. The largest families were Asteraceae, Lamiaceae, Fabaceae, Poaceae, Apiaceae, and Caryophyllaceae. In regards to biological form, the plants consisted of 41.1% of Hemicryptophytes, 26% of Therophytes, 13.41% of Champhytes, 13.41% of Geophytes, 3.2% of Phanorphytes, 1.6% of Parasites, and 0.96% of the Helophytes. For geographical distribution, the largest share of IranoTuranian elements (67.52%), and other species belonged to two or more geographic areas. Finally, 34 plant species were endemics of Iran. https://tbj.ui.ac.ir/article_26632_808d9b33fabe5c2746184966a2d6bfcc.pdf