University of Isfahan Taxonomy and Biosystematics 3115-9001 14 50 2022 05 22 An Overview of the Evolution of the Genus Astragalus (Fabaceae) in the Old World مروری بر روند تکامل سردۀ گون (باقلاییان) در دنیای قدیم 1 24 26608 10.22108/tbj.2022.133218.1196 EN Ali Asghar Maassoumi Professor, Botany Research Division, Research Institute of Forests & Rangelands, Agricultural Research, Education and Extension ‎Organization (AREEO), Tehran, Iran Parvaneh Ashouri Assistant Professor, Rangeland Research Division, Research Institute of Forests & Rangelands, Agricultural Research, Education and ‎Extension Organization (AREEO), Tehran, Iran Farzaneh Khajoei Nasab Ph. D. Graduate of Plant Systematics, Department of Plant Sciences and Biotechnology, Faculty of Life Sciences and ‎Biotechnology, ‎ Shahid Beheshti University, Tehran, Iran‏.‏ Journal Article 2022 04 11 The present study investigated the trend of divergence and fragmentation of different sections of <em>Astragalus</em> in the Old World. <em>Astragalus</em> species are divided into three groups: primitive, intermediate, and advanced based on previous research and the distribution maps of each of these groups in the Old World were presented. The primitive group consisted of herbaceous sections with simple hairs and an old drought-tolerant section with woody stems and bifurcating hairs, which were densely distributed in Asia and Africa and scattered in Europe. The intermediate group, with thorny cushion shapes, was often scattered in the Zagros and Alborz mountains, mountainous regions of Turkey, Lebanon, and Jordan, and extended from the east to Afghanistan, the Hindu Kush, and the southern parts of the Himalayas. The results of the study showed that the distribution pattern of the advanced group was very heterogeneous and its pattern was consistent with the primitive group. The simple hair sections were scattered below 35 degrees north latitude and the bifurcated hairs sections were more frequently distributed above 35 degrees north latitude. Annual <em>Astragalus</em> species were heterogeneously distributed in all three main groups. In all three groups, parallel evolution took place at the level of sections and species. At each point of distribution, their number had a limited distribution. In addition, some species achieved non-genetic diversity by functional or regulatory genetic, hereditary or structural mechanisms and created distinct species that adapted in nature to the ecological conditions of the same areas and continued to regenerate with even more distributions. https://tbj.ui.ac.ir/article_26608_57a72c573d08f48fd6c14977e1102e25.pdf