Studies on some anatomical features of selected plant species grown in sand dune areas of North Sinai, Egypt Anwar A. Elkharbotly Desert Research Center, Sand dunes Dept., Environment and Arid Lands Cultivation Division, Matariya, P.O. Box 11753, Cairo, Egypt abstract article info Article history: Received 17 August 2015 Received in revised form 17 March 2016 Accepted 18 March 2016 The present investigation aims at studying some anatomical features of some selected native plant species in arid environments of sand dunes at North Sinai, Egypt. Plant samples were collected from three localities; Coastal sand dunes of Balouza (Zygophyllum album, Zygophyllaceae; root, stem and leaf); sand sheets of El-Arish city (stems of Anabasis articulata, Amaranthaceae and Salsola tetrandra, Chenopodiaceae) and El-Owga interdune areas (Fagonia indica, Zygophyllaceae; stem and root, Zygophyllum album, stem). Anatomical adaptations in leaves of Zygophyllum album include the presence of palisade layers on the adaxial and abaxial surfaces, thick cu- ticle layer cover the epidermis, spongy mesophyll and the presence of water storage cells. Stem anatomical ad- aptations in different plant species as general observations were the presence of thick cuticle, multiepidermal layers, palisade shape chlorenchyma, patches of sclerenchymatous fiber in the cortex and the precipitation of raphid and druse crystals of different sizes in plant tissues. Root adaptations in Zygophyllum album and Fagonia indica include the presence of periderm layers composed of compacted and elongated cells of different origins and increase the number of small xylem vessels which can guarantee the continuity of water uptake from soil in the case of xylem embolism. © 2016 Ecological Society of China. Published by Elsevier B.V. All rights reserved. Keywords: Anatomical adaptations Palisade layer multiepidermal layers Cuticle Spongy mesophyll Periderm Water storage cells Arid environments Native plants to sand dunes 1. Introduction Native plants to arid environments in sand dune areas are very im- portant for sand dune stabilization and reducing wind and water ero- sion resulting from severe floods. Such plants have different anatomical and physiological adaptations to maintain survive under ad- verse conditions of limited water resources and active sand encroach- ment. Hence plants can exhibit a quick growth development to overcome being buried by sand accumulation. Substantial leaf loss and more developed vascular are also noticeable and the presence of water storage tissues in mesophyll cells to withstand drought, this is consider as a prevalent character of xeromorphic leaves [31,33]. Plants in such circumstances tend to reduce it by transpiring surface area by means of substantial leaf loss. Therefore, plants with small leaves are more common in dry habitats [8,22–24]. A very common characteristic of xeromorphic leaves is a lower surface area to volume ratio, thick cu- ticle and sunken stomata, thus reducing water loss [19,20,30]. The pres- ence of a palisade layer on both leaf surface, together with a mesophyll composed of smaller cells and reduced intracellular spaces is reported to be a characteristic of xerophytic species [9,25]. The increase of meso- phyll thickness enhances the photosynthetic capacity if it is accompanied by an increase in the number of chloroplasts exposed near the surface area facing the intercellular spacing [21]. The presence of additional layers of palisade parenchyma at the ex- pense of spongy tissue is also considered a way to increase the path of water through intercellular spaces to reach stomata; this would be a strategy to increase water use efficiency (ratio of carbon dioxide fixed to water lost) [17]. Many plants in desert environments produce differ- ent shapes and volumes of crystals in plant tissues. Calcium (Ca) oxa- lates are among the most abundant crystals present in different plant tissues, it is found as crystalline deposits [2,7,12,32]. The formation of calcium (Ca) oxalate crystal is considered to be a high capacity mecha- nism for regulating Ca in many plants. Needle shaped raphides and mul- tifaceted druse crystals are the two common types of crystals formed in the plant tissues. [18]. In a study on four genera of the tribe Salsoleae, Chenopodiaceae, crystals of calcium (Ca) oxalate are formed in Anabasis articulata, they precipitated in epidermis, palisade shape chlorenchyma, cortex and in the vascular cylinder and also they found fibers in the cor- tex and in the vascular bundles [10]. Fibers are found in many plant tissues and in various organs of the plant and vary in position, they are sclerenchymatous (thick-walled) cells that form the bulk of mechanical or supporting tissue in the plants, [29]. The chief function of the fibers to the plant is to give it mechanical strength and save the plant from the various stresses and strains of the environmental factors e.g., strong winds. Their presence in the leaf gives Acta Ecologica Sinica 36 (2016) 246–251 E-mail address: anwar_online@yahoo.com. http://dx.doi.org/10.1016/j.chnaes.2016.03.004 1872-2032/© 2016 Ecological Society of China. Published by Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Acta Ecologica Sinica journal homepage: www.elsevier.com/locate/chnaes