An Overview of Ecological Anatomy of Poaceae Halophytes from Iran Maryam Keshavarzi Contents 1 Introduction ................................................................................... 2 2 Halophytic Poaceae in Iran ................................................................... 4 3 Effect of Salinity on Poaceae ................................................................. 5 4 Anatomical Adaptation to Salinity in Poaceae ............................................... 8 4.1 Kranz Anatomy ......................................................................... 8 4.2 Sclerenchyma Tissue ................................................................... 9 4.3 Vascular Bundles ....................................................................... 10 4.4 Cortex and Pith ......................................................................... 11 4.5 Bulliform Cells ......................................................................... 14 4.6 Silica Bodies ............................................................................ 15 4.7 Epicuticular Wax ....................................................................... 18 4.8 Salt Glands .............................................................................. 19 5 Conclusion .................................................................................... 25 References ........................................................................................ 26 Abstract The Poaceae, as the most important monocotyledons, are adapted to different environmental conditions. Some grasses are distributed in saline soils or encoun- tered with the waterlogging in saline habitats. There are some adaptive structural features which are efficient in both salt and drought tolerance. Some aspects of plant tolerance to salinity are based on anatomical traits. Halophytes show differences in anatomical features, such as adaptive responses to salinity. In this chapter, the general ecological anatomy of grasses of saline habitats is considered, aiming to provide a detailed review on the typical anatomical features of halo- phyte grasses. This kind of grasses uses two main strategies to overcome the toxicity of salt uptake: dilution of salts by increasing succulence; or by excreting excess salts by use of secretory structures such as salt glands. Besides these two M. Keshavarzi (*) Plant Sciences Department, Alzahra University, Tehran, Iran e-mail: M.keshavarzi@alzahra.ac.ir © Springer Nature Switzerland AG 2020 M. N. Grigore (ed.), Handbook of Halophytes, https://doi.org/10.1007/978-3-030-17854-3_35-1 1