全球变化知识资源中心

Carex L., representing approximately 2,100 species, is one of the world's largest angiosperm genera and nearly cosmopolitan in distribution. However, limited studies are conducted on this genus in the Western Himalayas, from both a molecular and a morphologic perspective. In this study, Carex species were explored across the Western Himalayan range to identify Carex species previously unknown from the region and to contextualize collected plants in a large barcoding dataset generated by the Global Carex Group. Phylogenetic relationships among collected specimens were estimated using maximum likelihood (ML) analysis of three barcoding genes (the external and internal transcribed spacer regions of nuclear ribosomal DNA, ETS and ITS respectively, and the plastid matK gene). Micromorphological traits including epidermal features of the pistillate scale were inspected using light and scanning electron microscopy. Eighteen Carex species were sampled from the Western Himalayan region of Pakistan. Among these, Carex simpliciuscula Wahlenb. (1803: 141), previously with doubtful record in the Flora of Pakistan, was confirmed for the region. Further, 12 range extensions for Carex species were identified in the Western Himalayas. Additionally, ten variable micro- and macromorphological characters of pistillate scale were evident that may serve useful for future taxonomic work and identification of the genus in the region; combinations of hooks, prickles, papillae and various trichomes under the scanning electron microscope. These results have great implications for understanding taxonomic and floristic scope of Carex species in the Western Himalayas region particularly in global climate change and its associated impacts. (C) 2019 Friends Science Publishers