Abstract: Background and Objective: Tragus berteronianus Schult. is an annual grass in dry habitats of southwestern Saudi Arabia. This species reveals dissimilar wettability on both leaf surfaces with dew collecting ability. Therefore, the objective of this study was to determine the micromorphological features of Tragus berteronianus Schult, responsible for those characters and their ecological significance. Materials and Methods: Both leaf surfaces were studied by SEM. Dimensions of surface microstructures were measured and analyzed. Elemental analysis of the leaf epidermal surface was determined by energy-dispersive X-ray spectroscopy (EDS). Dew collecting ability was observed in the field as well as in the laboratory by exposing leaf surfaces to the mist stream generated by a cold mist humidifier. Contact angles of droplets precipitated on the leaf surfaces were measured from digital images. Results: Adaxial leaf surface showed hierarchical structures from sub-millimetric to micro- and nano-scale, in which dimensions of micro projections and spacing between them denoting to Cassie state. Abaxial leaf surface, in contrast, showed a different pattern of microstructures, in which dimensions of micro projections and spacing between them denoting to Wenzel state. The adaxial leaf surface was superhydrophobic, whereas the abaxial surface was hydrophilic. Spines of leaf margin have a high ability to collect dew. Conclusion: Wettability in Tragus berteronianus leaf differs on both leaf surfaces due to microstructure traits and can explain high adaptation in dry habitats by using dew efficiently as an alternative source of water.